diff --git a/nearby/service/java/com/android/server/nearby/NearbyConfiguration.java b/nearby/service/java/com/android/server/nearby/NearbyConfiguration.java
index 07e6f0c..0c10af2 100644
--- a/nearby/service/java/com/android/server/nearby/NearbyConfiguration.java
+++ b/nearby/service/java/com/android/server/nearby/NearbyConfiguration.java
@@ -22,6 +22,7 @@
 import androidx.annotation.NonNull;
 
 import com.android.internal.annotations.GuardedBy;
+import com.android.server.nearby.managers.DiscoveryProviderManager;
 
 import java.util.concurrent.Executors;
 
@@ -46,6 +47,12 @@
      */
     public static final String NEARBY_SUPPORT_TEST_APP = "nearby_support_test_app";
 
+    /**
+     * Flag to control which version of DiscoveryProviderManager should be used.
+     */
+    public static final String NEARBY_REFACTOR_DISCOVERY_MANAGER =
+            "nearby_refactor_discovery_manager";
+
     private static final boolean IS_USER_BUILD = "user".equals(Build.TYPE);
 
     private final DeviceConfigListener mDeviceConfigListener = new DeviceConfigListener();
@@ -57,11 +64,27 @@
     private int mNanoAppMinVersion;
     @GuardedBy("mDeviceConfigLock")
     private boolean mSupportTestApp;
+    @GuardedBy("mDeviceConfigLock")
+    private boolean mRefactorDiscoveryManager;
 
     public NearbyConfiguration() {
         mDeviceConfigListener.start();
     }
 
+    private static boolean getDeviceConfigBoolean(final String name, final boolean defaultValue) {
+        final String value = getDeviceConfigProperty(name);
+        return value != null ? Boolean.parseBoolean(value) : defaultValue;
+    }
+
+    private static int getDeviceConfigInt(final String name, final int defaultValue) {
+        final String value = getDeviceConfigProperty(name);
+        return value != null ? Integer.parseInt(value) : defaultValue;
+    }
+
+    private static String getDeviceConfigProperty(String name) {
+        return DeviceConfig.getProperty(DeviceConfig.NAMESPACE_NEARBY, name);
+    }
+
     /**
      * Returns whether broadcasting legacy presence spec is enabled.
      */
@@ -86,6 +109,16 @@
         }
     }
 
+    /**
+     * @return {@code true} if use {@link DiscoveryProviderManager} or use
+     * DiscoveryProviderManagerLegacy if {@code false}.
+     */
+    public boolean refactorDiscoveryManager() {
+        synchronized (mDeviceConfigLock) {
+            return mRefactorDiscoveryManager;
+        }
+    }
+
     private class DeviceConfigListener implements DeviceConfig.OnPropertiesChangedListener {
         public void start() {
             DeviceConfig.addOnPropertiesChangedListener(DeviceConfig.NAMESPACE_NEARBY,
@@ -102,21 +135,9 @@
                         NEARBY_MAINLINE_NANO_APP_MIN_VERSION, 0 /* defaultValue */);
                 mSupportTestApp = !IS_USER_BUILD && getDeviceConfigBoolean(
                         NEARBY_SUPPORT_TEST_APP, false /* defaultValue */);
+                mRefactorDiscoveryManager = getDeviceConfigBoolean(
+                        NEARBY_REFACTOR_DISCOVERY_MANAGER, false /* defaultValue */);
             }
         }
     }
-
-    private static boolean getDeviceConfigBoolean(final String name, final boolean defaultValue) {
-        final String value = getDeviceConfigProperty(name);
-        return value != null ? Boolean.parseBoolean(value) : defaultValue;
-    }
-
-    private static int getDeviceConfigInt(final String name, final int defaultValue) {
-        final String value = getDeviceConfigProperty(name);
-        return value != null ? Integer.parseInt(value) : defaultValue;
-    }
-
-    private static String getDeviceConfigProperty(String name) {
-        return DeviceConfig.getProperty(DeviceConfig.NAMESPACE_NEARBY, name);
-    }
 }
diff --git a/nearby/service/java/com/android/server/nearby/NearbyService.java b/nearby/service/java/com/android/server/nearby/NearbyService.java
index 8d35e08..2ac2b00 100644
--- a/nearby/service/java/com/android/server/nearby/NearbyService.java
+++ b/nearby/service/java/com/android/server/nearby/NearbyService.java
@@ -45,7 +45,9 @@
 import com.android.server.nearby.fastpair.FastPairManager;
 import com.android.server.nearby.injector.Injector;
 import com.android.server.nearby.managers.BroadcastProviderManager;
+import com.android.server.nearby.managers.DiscoveryManager;
 import com.android.server.nearby.managers.DiscoveryProviderManager;
+import com.android.server.nearby.managers.DiscoveryProviderManagerLegacy;
 import com.android.server.nearby.presence.PresenceManager;
 import com.android.server.nearby.provider.FastPairDataProvider;
 import com.android.server.nearby.util.identity.CallerIdentity;
@@ -80,18 +82,21 @@
                     }
                 }
             };
-    private final DiscoveryProviderManager mProviderManager;
+    private final DiscoveryManager mDiscoveryProviderManager;
     private final BroadcastProviderManager mBroadcastProviderManager;
 
     public NearbyService(Context context) {
         mContext = context;
         mInjector = new SystemInjector(context);
-        mProviderManager = new DiscoveryProviderManager(context, mInjector);
         mBroadcastProviderManager = new BroadcastProviderManager(context, mInjector);
         final LocatorContextWrapper lcw = new LocatorContextWrapper(context, null);
         mFastPairManager = new FastPairManager(lcw);
         mPresenceManager = new PresenceManager(lcw);
         mNearbyConfiguration = new NearbyConfiguration();
+        mDiscoveryProviderManager =
+                mNearbyConfiguration.refactorDiscoveryManager()
+                        ? new DiscoveryProviderManager(context, mInjector)
+                        : new DiscoveryProviderManagerLegacy(context, mInjector);
     }
 
     @VisibleForTesting
@@ -108,7 +113,7 @@
         CallerIdentity identity = CallerIdentity.fromBinder(mContext, packageName, attributionTag);
         DiscoveryPermissions.enforceDiscoveryPermission(mContext, identity);
 
-        return mProviderManager.registerScanListener(scanRequest, listener, identity);
+        return mDiscoveryProviderManager.registerScanListener(scanRequest, listener, identity);
     }
 
     @Override
@@ -119,7 +124,7 @@
         CallerIdentity identity = CallerIdentity.fromBinder(mContext, packageName, attributionTag);
         DiscoveryPermissions.enforceDiscoveryPermission(mContext, identity);
 
-        mProviderManager.unregisterScanListener(listener);
+        mDiscoveryProviderManager.unregisterScanListener(listener);
     }
 
     @Override
@@ -147,7 +152,7 @@
 
     @Override
     public void queryOffloadCapability(IOffloadCallback callback) {
-        mProviderManager.queryOffloadCapability(callback);
+        mDiscoveryProviderManager.queryOffloadCapability(callback);
     }
 
     /**
@@ -174,7 +179,7 @@
                     // Initialize ContextManager for CHRE scan.
                     ((SystemInjector) mInjector).initializeContextHubManager();
                 }
-                mProviderManager.init();
+                mDiscoveryProviderManager.init();
                 mContext.registerReceiver(
                         mBluetoothReceiver,
                         new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));
diff --git a/nearby/service/java/com/android/server/nearby/managers/DiscoveryManager.java b/nearby/service/java/com/android/server/nearby/managers/DiscoveryManager.java
new file mode 100644
index 0000000..c9b9a43
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/DiscoveryManager.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import android.nearby.IScanListener;
+import android.nearby.NearbyManager;
+import android.nearby.ScanRequest;
+import android.nearby.aidl.IOffloadCallback;
+
+import com.android.server.nearby.util.identity.CallerIdentity;
+
+/**
+ * Interface added for flagging DiscoveryProviderManager refactor. After the
+ * nearby_refactor_discovery_manager flag is fully rolled out, this can be deleted.
+ */
+public interface DiscoveryManager {
+
+    /**
+     * Registers the listener in the manager and starts scan according to the requested scan mode.
+     */
+    @NearbyManager.ScanStatus
+    int registerScanListener(ScanRequest scanRequest, IScanListener listener,
+            CallerIdentity callerIdentity);
+
+    /**
+     * Unregisters the listener in the manager and adjusts the scan mode if necessary afterwards.
+     */
+    void unregisterScanListener(IScanListener listener);
+
+    /** Query offload capability in a device. */
+    void queryOffloadCapability(IOffloadCallback callback);
+
+    /** Called after boot completed. */
+    void init();
+}
diff --git a/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManager.java b/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManager.java
index 29b18f3..4cda93a 100644
--- a/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManager.java
+++ b/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManager.java
@@ -21,320 +21,74 @@
 import static com.android.server.nearby.NearbyService.TAG;
 
 import android.annotation.Nullable;
-import android.app.AppOpsManager;
 import android.content.Context;
 import android.nearby.DataElement;
 import android.nearby.IScanListener;
 import android.nearby.NearbyDeviceParcelable;
 import android.nearby.NearbyManager;
 import android.nearby.PresenceScanFilter;
-import android.nearby.ScanCallback;
 import android.nearby.ScanFilter;
 import android.nearby.ScanRequest;
 import android.nearby.aidl.IOffloadCallback;
-import android.os.IBinder;
-import android.os.RemoteException;
 import android.util.Log;
 
-import com.android.internal.annotations.GuardedBy;
+import androidx.annotation.NonNull;
+
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.server.nearby.injector.Injector;
-import com.android.server.nearby.metrics.NearbyMetrics;
-import com.android.server.nearby.presence.PresenceDiscoveryResult;
+import com.android.server.nearby.managers.registration.DiscoveryRegistration;
 import com.android.server.nearby.provider.AbstractDiscoveryProvider;
 import com.android.server.nearby.provider.BleDiscoveryProvider;
 import com.android.server.nearby.provider.ChreCommunication;
 import com.android.server.nearby.provider.ChreDiscoveryProvider;
-import com.android.server.nearby.provider.PrivacyFilter;
 import com.android.server.nearby.util.identity.CallerIdentity;
-import com.android.server.nearby.util.permissions.DiscoveryPermissions;
 
 import java.util.ArrayList;
-import java.util.HashMap;
+import java.util.Collection;
 import java.util.List;
-import java.util.Map;
-import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
-import java.util.stream.Collectors;
+
+import javax.annotation.concurrent.GuardedBy;
 
 /** Manages all aspects of discovery providers. */
-public class DiscoveryProviderManager implements AbstractDiscoveryProvider.Listener {
+public class DiscoveryProviderManager extends
+        ListenerMultiplexer<IScanListener, DiscoveryRegistration, MergedDiscoveryRequest> implements
+        AbstractDiscoveryProvider.Listener,
+        DiscoveryManager {
 
     protected final Object mLock = new Object();
-    private final Context mContext;
-    private final BleDiscoveryProvider mBleDiscoveryProvider;
     @VisibleForTesting
     @Nullable
     final ChreDiscoveryProvider mChreDiscoveryProvider;
-    private @ScanRequest.ScanMode int mScanMode;
+    private final Context mContext;
+    private final BleDiscoveryProvider mBleDiscoveryProvider;
     private final Injector mInjector;
-
-    @GuardedBy("mLock")
-    private Map<IBinder, ScanListenerRecord> mScanTypeScanListenerRecordMap;
-
-    @Override
-    public void onNearbyDeviceDiscovered(NearbyDeviceParcelable nearbyDevice) {
-        synchronized (mLock) {
-            AppOpsManager appOpsManager = Objects.requireNonNull(mInjector.getAppOpsManager());
-            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
-                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
-                if (record == null) {
-                    Log.w(TAG, "DiscoveryProviderManager cannot find the scan record.");
-                    continue;
-                }
-                CallerIdentity callerIdentity = record.getCallerIdentity();
-                if (!DiscoveryPermissions.noteDiscoveryResultDelivery(
-                        appOpsManager, callerIdentity)) {
-                    Log.w(TAG, "[DiscoveryProviderManager] scan permission revoked "
-                            + "- not forwarding results");
-                    try {
-                        record.getScanListener().onError(ScanCallback.ERROR_PERMISSION_DENIED);
-                    } catch (RemoteException e) {
-                        Log.w(TAG, "DiscoveryProviderManager failed to report error.", e);
-                    }
-                    return;
-                }
-
-                if (nearbyDevice.getScanType() == SCAN_TYPE_NEARBY_PRESENCE) {
-                    List<ScanFilter> presenceFilters =
-                            record.getScanRequest().getScanFilters().stream()
-                                    .filter(
-                                            scanFilter ->
-                                                    scanFilter.getType()
-                                                            == SCAN_TYPE_NEARBY_PRESENCE)
-                                    .collect(Collectors.toList());
-                    if (!presenceFilterMatches(nearbyDevice, presenceFilters)) {
-                        Log.d(TAG, "presence filter does not match for "
-                                + "the scanned Presence Device");
-                        continue;
-                    }
-                }
-                try {
-                    record.getScanListener()
-                            .onDiscovered(
-                                    PrivacyFilter.filter(
-                                            record.getScanRequest().getScanType(), nearbyDevice));
-                    NearbyMetrics.logScanDeviceDiscovered(
-                            record.hashCode(), record.getScanRequest(), nearbyDevice);
-                } catch (RemoteException e) {
-                    Log.w(TAG, "DiscoveryProviderManager failed to report onDiscovered.", e);
-                }
-            }
-        }
-    }
-
-    @Override
-    public void onError(int errorCode) {
-        synchronized (mLock) {
-            AppOpsManager appOpsManager = Objects.requireNonNull(mInjector.getAppOpsManager());
-            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
-                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
-                if (record == null) {
-                    Log.w(TAG, "DiscoveryProviderManager cannot find the scan record.");
-                    continue;
-                }
-                CallerIdentity callerIdentity = record.getCallerIdentity();
-                if (!DiscoveryPermissions.noteDiscoveryResultDelivery(
-                        appOpsManager, callerIdentity)) {
-                    Log.w(TAG, "[DiscoveryProviderManager] scan permission revoked "
-                            + "- not forwarding results");
-                    try {
-                        record.getScanListener().onError(ScanCallback.ERROR_PERMISSION_DENIED);
-                    } catch (RemoteException e) {
-                        Log.w(TAG, "DiscoveryProviderManager failed to report error.", e);
-                    }
-                    return;
-                }
-
-                try {
-                    record.getScanListener().onError(errorCode);
-                } catch (RemoteException e) {
-                    Log.w(TAG, "DiscoveryProviderManager failed to report onError.", e);
-                }
-            }
-        }
-    }
+    private final Executor mExecutor;
 
     public DiscoveryProviderManager(Context context, Injector injector) {
+        Log.v(TAG, "DiscoveryProviderManager: ");
         mContext = context;
         mBleDiscoveryProvider = new BleDiscoveryProvider(mContext, injector);
-        Executor executor = Executors.newSingleThreadExecutor();
-        mChreDiscoveryProvider =
-                new ChreDiscoveryProvider(
-                        mContext, new ChreCommunication(injector, mContext, executor), executor);
-        mScanTypeScanListenerRecordMap = new HashMap<>();
+        mExecutor = Executors.newSingleThreadExecutor();
+        mChreDiscoveryProvider = new ChreDiscoveryProvider(mContext,
+                new ChreCommunication(injector, mContext, mExecutor), mExecutor);
         mInjector = injector;
     }
 
     @VisibleForTesting
-    DiscoveryProviderManager(Context context, Injector injector,
+    DiscoveryProviderManager(Context context, Executor executor, Injector injector,
             BleDiscoveryProvider bleDiscoveryProvider,
-            ChreDiscoveryProvider chreDiscoveryProvider,
-            Map<IBinder, ScanListenerRecord> scanTypeScanListenerRecordMap) {
+            ChreDiscoveryProvider chreDiscoveryProvider) {
         mContext = context;
+        mExecutor = executor;
         mInjector = injector;
         mBleDiscoveryProvider = bleDiscoveryProvider;
         mChreDiscoveryProvider = chreDiscoveryProvider;
-        mScanTypeScanListenerRecordMap = scanTypeScanListenerRecordMap;
     }
 
-    /** Called after boot completed. */
-    public void init() {
-        if (mInjector.getContextHubManager() != null) {
-            mChreDiscoveryProvider.init();
-        }
-        mChreDiscoveryProvider.getController().setListener(this);
-    }
-
-    /**
-     * Registers the listener in the manager and starts scan according to the requested scan mode.
-     */
-    @NearbyManager.ScanStatus
-    public int registerScanListener(ScanRequest scanRequest, IScanListener listener,
-            CallerIdentity callerIdentity) {
-        synchronized (mLock) {
-            ScanListenerDeathRecipient deathRecipient = (listener != null)
-                    ? new ScanListenerDeathRecipient(listener) : null;
-            IBinder listenerBinder = listener.asBinder();
-            if (listenerBinder != null && deathRecipient != null) {
-                try {
-                    listenerBinder.linkToDeath(deathRecipient, 0);
-                } catch (RemoteException e) {
-                    throw new IllegalArgumentException("Can't link to scan listener's death");
-                }
-            }
-            if (mScanTypeScanListenerRecordMap.containsKey(listener.asBinder())) {
-                ScanRequest savedScanRequest =
-                        mScanTypeScanListenerRecordMap.get(listenerBinder).getScanRequest();
-                if (scanRequest.equals(savedScanRequest)) {
-                    Log.d(TAG, "Already registered the scanRequest: " + scanRequest);
-                    return NearbyManager.ScanStatus.SUCCESS;
-                }
-            }
-            ScanListenerRecord scanListenerRecord =
-                    new ScanListenerRecord(scanRequest, listener, callerIdentity, deathRecipient);
-
-            Boolean started = startProviders(scanRequest);
-            if (started == null) {
-                return NearbyManager.ScanStatus.UNKNOWN;
-            }
-            if (!started) {
-                return NearbyManager.ScanStatus.ERROR;
-            }
-            mScanTypeScanListenerRecordMap.put(listenerBinder, scanListenerRecord);
-            NearbyMetrics.logScanStarted(scanListenerRecord.hashCode(), scanRequest);
-            if (mScanMode < scanRequest.getScanMode()) {
-                mScanMode = scanRequest.getScanMode();
-                invalidateProviderScanMode();
-            }
-            return NearbyManager.ScanStatus.SUCCESS;
-        }
-    }
-
-    /**
-     * Unregisters the listener in the manager and adjusts the scan mode if necessary afterwards.
-     */
-    public void unregisterScanListener(IScanListener listener) {
-        IBinder listenerBinder = listener.asBinder();
-        synchronized (mLock) {
-            if (!mScanTypeScanListenerRecordMap.containsKey(listenerBinder)) {
-                Log.w(
-                        TAG,
-                        "Cannot unregister the scanRequest because the request is never "
-                                + "registered.");
-                return;
-            }
-
-            ScanListenerRecord removedRecord =
-                    mScanTypeScanListenerRecordMap.remove(listenerBinder);
-            ScanListenerDeathRecipient deathRecipient = removedRecord.getDeathRecipient();
-            if (listenerBinder != null && deathRecipient != null) {
-                listenerBinder.unlinkToDeath(removedRecord.getDeathRecipient(), 0);
-            }
-            Log.v(TAG, "DiscoveryProviderManager unregistered scan listener.");
-            NearbyMetrics.logScanStopped(removedRecord.hashCode(), removedRecord.getScanRequest());
-            if (mScanTypeScanListenerRecordMap.isEmpty()) {
-                Log.v(TAG, "DiscoveryProviderManager stops provider because there is no "
-                        + "scan listener registered.");
-                stopProviders();
-                return;
-            }
-
-            // TODO(b/221082271): updates the scan with reduced filters.
-
-            // Removes current highest scan mode requested and sets the next highest scan mode.
-            if (removedRecord.getScanRequest().getScanMode() == mScanMode) {
-                Log.v(TAG, "DiscoveryProviderManager starts to find the new highest scan mode "
-                        + "because the highest scan mode listener was unregistered.");
-                @ScanRequest.ScanMode int highestScanModeRequested = ScanRequest.SCAN_MODE_NO_POWER;
-                // find the next highest scan mode;
-                for (ScanListenerRecord record : mScanTypeScanListenerRecordMap.values()) {
-                    @ScanRequest.ScanMode int scanMode = record.getScanRequest().getScanMode();
-                    if (scanMode > highestScanModeRequested) {
-                        highestScanModeRequested = scanMode;
-                    }
-                }
-                if (mScanMode != highestScanModeRequested) {
-                    mScanMode = highestScanModeRequested;
-                    invalidateProviderScanMode();
-                }
-            }
-        }
-    }
-
-    /**
-     * Query offload capability in a device.
-     */
-    public void queryOffloadCapability(IOffloadCallback callback) {
-        mChreDiscoveryProvider.queryOffloadCapability(callback);
-    }
-
-    /**
-     * @return {@code null} when all providers are initializing
-     * {@code false} when fail to start all the providers
-     * {@code true} when any one of the provider starts successfully
-     */
-    @VisibleForTesting
-    @Nullable
-    Boolean startProviders(ScanRequest scanRequest) {
-        if (!scanRequest.isBleEnabled()) {
-            Log.w(TAG, "failed to start any provider because client disabled BLE");
-            return false;
-        }
-        List<ScanFilter> scanFilters = getPresenceScanFilters();
-        boolean chreOnly = isChreOnly(scanFilters);
-        Boolean chreAvailable = mChreDiscoveryProvider.available();
-        if (chreAvailable == null) {
-            if (chreOnly) {
-                Log.w(TAG, "client wants CHRE only and Nearby service is still querying CHRE"
-                        + " status");
-                return null;
-            }
-            startBleProvider(scanFilters);
-            return true;
-        }
-
-        if (!chreAvailable) {
-            if (chreOnly) {
-                Log.w(TAG, "failed to start any provider because client wants CHRE only and CHRE"
-                        + " is not available");
-                return false;
-            }
-            startBleProvider(scanFilters);
-            return true;
-        }
-
-        if (scanRequest.getScanType() == SCAN_TYPE_NEARBY_PRESENCE) {
-            startChreProvider(scanFilters);
-            return true;
-        }
-
-        startBleProvider(scanFilters);
-        return true;
-    }
-
-    private static boolean isChreOnly(List<ScanFilter> scanFilters) {
+    private static boolean isChreOnly(Set<ScanFilter> scanFilters) {
         for (ScanFilter scanFilter : scanFilters) {
             List<DataElement> dataElements =
                     ((PresenceScanFilter) scanFilter).getExtendedProperties();
@@ -355,41 +109,160 @@
         return false;
     }
 
-    private void startBleProvider(List<ScanFilter> scanFilters) {
+    @Override
+    public void onNearbyDeviceDiscovered(NearbyDeviceParcelable nearbyDevice) {
+        synchronized (mMultiplexerLock) {
+            Log.d(TAG, "Found device" + nearbyDevice);
+            deliverToListeners(registration -> {
+                try {
+                    return registration.onNearbyDeviceDiscovered(nearbyDevice);
+                } catch (Exception e) {
+                    Log.w(TAG, "DiscoveryProviderManager failed to report callback.", e);
+                    return null;
+                }
+            });
+        }
+    }
+
+    @Override
+    public void onError(int errorCode) {
+        synchronized (mMultiplexerLock) {
+            Log.e(TAG, "Error found during scanning.");
+            deliverToListeners(registration -> {
+                try {
+                    return registration.reportError(errorCode);
+                } catch (Exception e) {
+                    Log.w(TAG, "DiscoveryProviderManager failed to report error.", e);
+                    return null;
+                }
+            });
+        }
+    }
+
+    /** Called after boot completed. */
+    public void init() {
+        if (mInjector.getContextHubManager() != null) {
+            mChreDiscoveryProvider.init();
+        }
+        mChreDiscoveryProvider.getController().setListener(this);
+    }
+
+    /**
+     * Registers the listener in the manager and starts scan according to the requested scan mode.
+     */
+    @NearbyManager.ScanStatus
+    public int registerScanListener(ScanRequest scanRequest, IScanListener listener,
+            CallerIdentity callerIdentity) {
+        DiscoveryRegistration registration = new DiscoveryRegistration(this, scanRequest, listener,
+                mExecutor, callerIdentity, mMultiplexerLock, mInjector.getAppOpsManager());
+        synchronized (mMultiplexerLock) {
+            putRegistration(listener.asBinder(), registration);
+            return NearbyManager.ScanStatus.SUCCESS;
+        }
+    }
+
+    @Override
+    public void onRegister() {
+        Log.v(TAG, "Registering the DiscoveryProviderManager.");
+        startProviders();
+    }
+
+    @Override
+    public void onUnregister() {
+        Log.v(TAG, "Unregistering the DiscoveryProviderManager.");
+        stopProviders();
+    }
+
+    /**
+     * Unregisters the listener in the manager and adjusts the scan mode if necessary afterwards.
+     */
+    public void unregisterScanListener(IScanListener listener) {
+        Log.v(TAG, "Unregister scan listener");
+        synchronized (mMultiplexerLock) {
+            removeRegistration(listener.asBinder());
+        }
+        // TODO(b/221082271): updates the scan with reduced filters.
+    }
+
+    /**
+     * Query offload capability in a device.
+     */
+    public void queryOffloadCapability(IOffloadCallback callback) {
+        mChreDiscoveryProvider.queryOffloadCapability(callback);
+    }
+
+    /**
+     * @return {@code null} when all providers are initializing
+     * {@code false} when fail to start all the providers
+     * {@code true} when any one of the provider starts successfully
+     */
+    @VisibleForTesting
+    @Nullable
+    Boolean startProviders() {
+        synchronized (mMultiplexerLock) {
+            if (!mMerged.getMediums().contains(MergedDiscoveryRequest.Medium.BLE)) {
+                Log.w(TAG, "failed to start any provider because client disabled BLE");
+                return false;
+            }
+            Set<ScanFilter> scanFilters = mMerged.getScanFilters();
+            boolean chreOnly = isChreOnly(scanFilters);
+            Boolean chreAvailable = mChreDiscoveryProvider.available();
+            Log.v(TAG, "startProviders: chreOnly " + chreOnly + " chreAvailable " + chreAvailable);
+            if (chreAvailable == null) {
+                if (chreOnly) {
+                    Log.w(TAG, "client wants CHRE only and Nearby service is still querying CHRE"
+                            + " status");
+                    return null;
+                }
+                startBleProvider(scanFilters);
+                return true;
+            }
+
+            if (!chreAvailable) {
+                if (chreOnly) {
+                    Log.w(TAG,
+                            "failed to start any provider because client wants CHRE only and CHRE"
+                                    + " is not available");
+                    return false;
+                }
+                startBleProvider(scanFilters);
+                return true;
+            }
+
+            if (mMerged.getScanTypes().contains(SCAN_TYPE_NEARBY_PRESENCE)) {
+                startChreProvider(scanFilters);
+                Log.d(TAG, "startProviders: heeey");
+                return true;
+            }
+
+            Log.d(TAG, "startProviders: geagewage");
+
+            startBleProvider(scanFilters);
+            return true;
+        }
+    }
+
+    @GuardedBy("mMultiplexerLock")
+    private void startBleProvider(Set<ScanFilter> scanFilters) {
         if (!mBleDiscoveryProvider.getController().isStarted()) {
             Log.d(TAG, "DiscoveryProviderManager starts Ble scanning.");
             mBleDiscoveryProvider.getController().setListener(this);
-            mBleDiscoveryProvider.getController().setProviderScanMode(mScanMode);
-            mBleDiscoveryProvider.getController().setProviderScanFilters(scanFilters);
+            mBleDiscoveryProvider.getController().setProviderScanMode(mMerged.getScanMode());
+            mBleDiscoveryProvider.getController().setProviderScanFilters(
+                    new ArrayList<>(scanFilters));
             mBleDiscoveryProvider.getController().start();
         }
     }
 
     @VisibleForTesting
-    void startChreProvider(List<ScanFilter> scanFilters) {
-        Log.d(TAG, "DiscoveryProviderManager starts CHRE scanning.");
-        mChreDiscoveryProvider.getController().setProviderScanFilters(scanFilters);
-        mChreDiscoveryProvider.getController().setProviderScanMode(mScanMode);
+    @GuardedBy("mMultiplexerLock")
+    void startChreProvider(Collection<ScanFilter> scanFilters) {
+        Log.d(TAG, "DiscoveryProviderManager starts CHRE scanning. " + mMerged);
+        mChreDiscoveryProvider.getController().setProviderScanFilters(new ArrayList<>(scanFilters));
+        mChreDiscoveryProvider.getController().setProviderScanMode(mMerged.getScanMode());
         mChreDiscoveryProvider.getController().start();
     }
 
-    private List<ScanFilter> getPresenceScanFilters() {
-        synchronized (mLock) {
-            List<ScanFilter> scanFilters = new ArrayList();
-            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
-                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
-                List<ScanFilter> presenceFilters =
-                        record.getScanRequest().getScanFilters().stream()
-                                .filter(
-                                        scanFilter ->
-                                                scanFilter.getType() == SCAN_TYPE_NEARBY_PRESENCE)
-                                .collect(Collectors.toList());
-                scanFilters.addAll(presenceFilters);
-            }
-            return scanFilters;
-        }
-    }
-
     private void stopProviders() {
         stopBleProvider();
         stopChreProvider();
@@ -407,96 +280,40 @@
     @VisibleForTesting
     void invalidateProviderScanMode() {
         if (mBleDiscoveryProvider.getController().isStarted()) {
-            mBleDiscoveryProvider.getController().setProviderScanMode(mScanMode);
+            synchronized (mMultiplexerLock) {
+                mBleDiscoveryProvider.getController().setProviderScanMode(mMerged.getScanMode());
+            }
         } else {
-            Log.d(
-                    TAG,
-                    "Skip invalidating BleDiscoveryProvider scan mode because the provider not "
-                            + "started.");
+            Log.d(TAG, "Skip invalidating BleDiscoveryProvider scan mode because the provider not "
+                    + "started.");
         }
     }
 
-    @VisibleForTesting
-    static boolean presenceFilterMatches(
-            NearbyDeviceParcelable device, List<ScanFilter> scanFilters) {
-        if (scanFilters.isEmpty()) {
-            return true;
-        }
-        PresenceDiscoveryResult discoveryResult = PresenceDiscoveryResult.fromDevice(device);
-        for (ScanFilter scanFilter : scanFilters) {
-            PresenceScanFilter presenceScanFilter = (PresenceScanFilter) scanFilter;
-            if (discoveryResult.matches(presenceScanFilter)) {
-                return true;
+    @Override
+    public MergedDiscoveryRequest mergeRegistrations(
+            @NonNull Collection<DiscoveryRegistration> registrations) {
+        MergedDiscoveryRequest.Builder builder = new MergedDiscoveryRequest.Builder();
+        int scanMode = ScanRequest.SCAN_MODE_NO_POWER;
+        for (DiscoveryRegistration registration : registrations) {
+            builder.addActions(registration.getActions());
+            builder.addScanFilters(registration.getPresenceScanFilters());
+            Log.d(TAG,
+                    "mergeRegistrations: type is " + registration.getScanRequest().getScanType());
+            builder.addScanType(registration.getScanRequest().getScanType());
+            if (registration.getScanRequest().isBleEnabled()) {
+                builder.addMedium(MergedDiscoveryRequest.Medium.BLE);
+            }
+            int requestScanMode = registration.getScanRequest().getScanMode();
+            if (scanMode < requestScanMode) {
+                scanMode = requestScanMode;
             }
         }
-        return false;
+        builder.setScanMode(scanMode);
+        return builder.build();
     }
 
-    /**
-     * Class to make listener unregister after the binder is dead.
-     */
-    public class ScanListenerDeathRecipient implements IBinder.DeathRecipient {
-        public IScanListener listener;
-
-        ScanListenerDeathRecipient(IScanListener listener) {
-            this.listener = listener;
-        }
-
-        @Override
-        public void binderDied() {
-            Log.d(TAG, "Binder is dead - unregistering scan listener");
-            unregisterScanListener(listener);
-        }
-    }
-
-    @VisibleForTesting
-    static class ScanListenerRecord {
-
-        private final ScanRequest mScanRequest;
-
-        private final IScanListener mScanListener;
-
-        private final CallerIdentity mCallerIdentity;
-
-        private final ScanListenerDeathRecipient mDeathRecipient;
-
-        ScanListenerRecord(ScanRequest scanRequest, IScanListener iScanListener,
-                CallerIdentity callerIdentity, ScanListenerDeathRecipient deathRecipient) {
-            mScanListener = iScanListener;
-            mScanRequest = scanRequest;
-            mCallerIdentity = callerIdentity;
-            mDeathRecipient = deathRecipient;
-        }
-
-        IScanListener getScanListener() {
-            return mScanListener;
-        }
-
-        ScanRequest getScanRequest() {
-            return mScanRequest;
-        }
-
-        CallerIdentity getCallerIdentity() {
-            return mCallerIdentity;
-        }
-
-        ScanListenerDeathRecipient getDeathRecipient()  {
-            return mDeathRecipient;
-        }
-
-        @Override
-        public boolean equals(Object other) {
-            if (other instanceof ScanListenerRecord) {
-                ScanListenerRecord otherScanListenerRecord = (ScanListenerRecord) other;
-                return Objects.equals(mScanRequest, otherScanListenerRecord.mScanRequest)
-                        && Objects.equals(mScanListener, otherScanListenerRecord.mScanListener);
-            }
-            return false;
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(mScanListener, mScanRequest);
-        }
+    @Override
+    public void onMergedRegistrationsUpdated() {
+        invalidateProviderScanMode();
     }
 }
diff --git a/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManagerLegacy.java b/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManagerLegacy.java
new file mode 100644
index 0000000..e68d22a
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/DiscoveryProviderManagerLegacy.java
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import static android.nearby.ScanRequest.SCAN_TYPE_NEARBY_PRESENCE;
+
+import static com.android.server.nearby.NearbyService.TAG;
+
+import android.annotation.Nullable;
+import android.app.AppOpsManager;
+import android.content.Context;
+import android.nearby.DataElement;
+import android.nearby.IScanListener;
+import android.nearby.NearbyDeviceParcelable;
+import android.nearby.NearbyManager;
+import android.nearby.PresenceScanFilter;
+import android.nearby.ScanCallback;
+import android.nearby.ScanFilter;
+import android.nearby.ScanRequest;
+import android.nearby.aidl.IOffloadCallback;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.nearby.injector.Injector;
+import com.android.server.nearby.metrics.NearbyMetrics;
+import com.android.server.nearby.presence.PresenceDiscoveryResult;
+import com.android.server.nearby.provider.AbstractDiscoveryProvider;
+import com.android.server.nearby.provider.BleDiscoveryProvider;
+import com.android.server.nearby.provider.ChreCommunication;
+import com.android.server.nearby.provider.ChreDiscoveryProvider;
+import com.android.server.nearby.provider.PrivacyFilter;
+import com.android.server.nearby.util.identity.CallerIdentity;
+import com.android.server.nearby.util.permissions.DiscoveryPermissions;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+/** Manages all aspects of discovery providers. */
+public class DiscoveryProviderManagerLegacy implements AbstractDiscoveryProvider.Listener,
+        DiscoveryManager {
+
+    protected final Object mLock = new Object();
+    @VisibleForTesting
+    @Nullable
+    final ChreDiscoveryProvider mChreDiscoveryProvider;
+    private final Context mContext;
+    private final BleDiscoveryProvider mBleDiscoveryProvider;
+    private final Injector mInjector;
+    @ScanRequest.ScanMode
+    private int mScanMode;
+    @GuardedBy("mLock")
+    private final Map<IBinder, ScanListenerRecord> mScanTypeScanListenerRecordMap;
+
+    public DiscoveryProviderManagerLegacy(Context context, Injector injector) {
+        mContext = context;
+        mBleDiscoveryProvider = new BleDiscoveryProvider(mContext, injector);
+        Executor executor = Executors.newSingleThreadExecutor();
+        mChreDiscoveryProvider =
+                new ChreDiscoveryProvider(
+                        mContext, new ChreCommunication(injector, mContext, executor), executor);
+        mScanTypeScanListenerRecordMap = new HashMap<>();
+        mInjector = injector;
+        Log.v(TAG, "DiscoveryProviderManagerLegacy: ");
+    }
+
+    @VisibleForTesting
+    DiscoveryProviderManagerLegacy(Context context, Injector injector,
+            BleDiscoveryProvider bleDiscoveryProvider,
+            ChreDiscoveryProvider chreDiscoveryProvider,
+            Map<IBinder, ScanListenerRecord> scanTypeScanListenerRecordMap) {
+        mContext = context;
+        mInjector = injector;
+        mBleDiscoveryProvider = bleDiscoveryProvider;
+        mChreDiscoveryProvider = chreDiscoveryProvider;
+        mScanTypeScanListenerRecordMap = scanTypeScanListenerRecordMap;
+    }
+
+    private static boolean isChreOnly(List<ScanFilter> scanFilters) {
+        for (ScanFilter scanFilter : scanFilters) {
+            List<DataElement> dataElements =
+                    ((PresenceScanFilter) scanFilter).getExtendedProperties();
+            for (DataElement dataElement : dataElements) {
+                if (dataElement.getKey() != DataElement.DataType.SCAN_MODE) {
+                    continue;
+                }
+                byte[] scanModeValue = dataElement.getValue();
+                if (scanModeValue == null || scanModeValue.length == 0) {
+                    break;
+                }
+                if (Byte.toUnsignedInt(scanModeValue[0]) == ScanRequest.SCAN_MODE_CHRE_ONLY) {
+                    return true;
+                }
+            }
+
+        }
+        return false;
+    }
+
+    @VisibleForTesting
+    static boolean presenceFilterMatches(
+            NearbyDeviceParcelable device, List<ScanFilter> scanFilters) {
+        if (scanFilters.isEmpty()) {
+            return true;
+        }
+        PresenceDiscoveryResult discoveryResult = PresenceDiscoveryResult.fromDevice(device);
+        for (ScanFilter scanFilter : scanFilters) {
+            PresenceScanFilter presenceScanFilter = (PresenceScanFilter) scanFilter;
+            if (discoveryResult.matches(presenceScanFilter)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public void onNearbyDeviceDiscovered(NearbyDeviceParcelable nearbyDevice) {
+        synchronized (mLock) {
+            AppOpsManager appOpsManager = Objects.requireNonNull(mInjector.getAppOpsManager());
+            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
+                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
+                if (record == null) {
+                    Log.w(TAG, "DiscoveryProviderManager cannot find the scan record.");
+                    continue;
+                }
+                CallerIdentity callerIdentity = record.getCallerIdentity();
+                if (!DiscoveryPermissions.noteDiscoveryResultDelivery(
+                        appOpsManager, callerIdentity)) {
+                    Log.w(TAG, "[DiscoveryProviderManager] scan permission revoked "
+                            + "- not forwarding results");
+                    try {
+                        record.getScanListener().onError(ScanCallback.ERROR_PERMISSION_DENIED);
+                    } catch (RemoteException e) {
+                        Log.w(TAG, "DiscoveryProviderManager failed to report error.", e);
+                    }
+                    return;
+                }
+
+                if (nearbyDevice.getScanType() == SCAN_TYPE_NEARBY_PRESENCE) {
+                    List<ScanFilter> presenceFilters =
+                            record.getScanRequest().getScanFilters().stream()
+                                    .filter(
+                                            scanFilter ->
+                                                    scanFilter.getType()
+                                                            == SCAN_TYPE_NEARBY_PRESENCE)
+                                    .collect(Collectors.toList());
+                    if (!presenceFilterMatches(nearbyDevice, presenceFilters)) {
+                        Log.d(TAG, "presence filter does not match for "
+                                + "the scanned Presence Device");
+                        continue;
+                    }
+                }
+                try {
+                    record.getScanListener()
+                            .onDiscovered(
+                                    PrivacyFilter.filter(
+                                            record.getScanRequest().getScanType(), nearbyDevice));
+                    NearbyMetrics.logScanDeviceDiscovered(
+                            record.hashCode(), record.getScanRequest(), nearbyDevice);
+                } catch (RemoteException e) {
+                    Log.w(TAG, "DiscoveryProviderManager failed to report onDiscovered.", e);
+                }
+            }
+        }
+    }
+
+    @Override
+    public void onError(int errorCode) {
+        synchronized (mLock) {
+            AppOpsManager appOpsManager = Objects.requireNonNull(mInjector.getAppOpsManager());
+            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
+                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
+                if (record == null) {
+                    Log.w(TAG, "DiscoveryProviderManager cannot find the scan record.");
+                    continue;
+                }
+                CallerIdentity callerIdentity = record.getCallerIdentity();
+                if (!DiscoveryPermissions.noteDiscoveryResultDelivery(
+                        appOpsManager, callerIdentity)) {
+                    Log.w(TAG, "[DiscoveryProviderManager] scan permission revoked "
+                            + "- not forwarding results");
+                    try {
+                        record.getScanListener().onError(ScanCallback.ERROR_PERMISSION_DENIED);
+                    } catch (RemoteException e) {
+                        Log.w(TAG, "DiscoveryProviderManager failed to report error.", e);
+                    }
+                    return;
+                }
+
+                try {
+                    record.getScanListener().onError(errorCode);
+                } catch (RemoteException e) {
+                    Log.w(TAG, "DiscoveryProviderManager failed to report onError.", e);
+                }
+            }
+        }
+    }
+
+    /** Called after boot completed. */
+    public void init() {
+        if (mInjector.getContextHubManager() != null) {
+            mChreDiscoveryProvider.init();
+        }
+        mChreDiscoveryProvider.getController().setListener(this);
+    }
+
+    /**
+     * Registers the listener in the manager and starts scan according to the requested scan mode.
+     */
+    @NearbyManager.ScanStatus
+    public int registerScanListener(ScanRequest scanRequest, IScanListener listener,
+            CallerIdentity callerIdentity) {
+        synchronized (mLock) {
+            ScanListenerDeathRecipient deathRecipient = (listener != null)
+                    ? new ScanListenerDeathRecipient(listener) : null;
+            IBinder listenerBinder = listener.asBinder();
+            if (listenerBinder != null && deathRecipient != null) {
+                try {
+                    listenerBinder.linkToDeath(deathRecipient, 0);
+                } catch (RemoteException e) {
+                    throw new IllegalArgumentException("Can't link to scan listener's death");
+                }
+            }
+            if (mScanTypeScanListenerRecordMap.containsKey(listener.asBinder())) {
+                ScanRequest savedScanRequest =
+                        mScanTypeScanListenerRecordMap.get(listenerBinder).getScanRequest();
+                if (scanRequest.equals(savedScanRequest)) {
+                    Log.d(TAG, "Already registered the scanRequest: " + scanRequest);
+                    return NearbyManager.ScanStatus.SUCCESS;
+                }
+            }
+            ScanListenerRecord scanListenerRecord =
+                    new ScanListenerRecord(scanRequest, listener, callerIdentity, deathRecipient);
+
+            Boolean started = startProviders(scanRequest);
+            if (started == null) {
+                return NearbyManager.ScanStatus.UNKNOWN;
+            }
+            if (!started) {
+                return NearbyManager.ScanStatus.ERROR;
+            }
+            mScanTypeScanListenerRecordMap.put(listenerBinder, scanListenerRecord);
+            NearbyMetrics.logScanStarted(scanListenerRecord.hashCode(), scanRequest);
+            if (mScanMode < scanRequest.getScanMode()) {
+                mScanMode = scanRequest.getScanMode();
+                invalidateProviderScanMode();
+            }
+            return NearbyManager.ScanStatus.SUCCESS;
+        }
+    }
+
+    /**
+     * Unregisters the listener in the manager and adjusts the scan mode if necessary afterwards.
+     */
+    public void unregisterScanListener(IScanListener listener) {
+        IBinder listenerBinder = listener.asBinder();
+        synchronized (mLock) {
+            if (!mScanTypeScanListenerRecordMap.containsKey(listenerBinder)) {
+                Log.w(
+                        TAG,
+                        "Cannot unregister the scanRequest because the request is never "
+                                + "registered.");
+                return;
+            }
+
+            ScanListenerRecord removedRecord =
+                    mScanTypeScanListenerRecordMap.remove(listenerBinder);
+            ScanListenerDeathRecipient deathRecipient = removedRecord.getDeathRecipient();
+            if (listenerBinder != null && deathRecipient != null) {
+                listenerBinder.unlinkToDeath(removedRecord.getDeathRecipient(), 0);
+            }
+            Log.v(TAG, "DiscoveryProviderManager unregistered scan listener.");
+            NearbyMetrics.logScanStopped(removedRecord.hashCode(), removedRecord.getScanRequest());
+            if (mScanTypeScanListenerRecordMap.isEmpty()) {
+                Log.v(TAG, "DiscoveryProviderManager stops provider because there is no "
+                        + "scan listener registered.");
+                stopProviders();
+                return;
+            }
+
+            // TODO(b/221082271): updates the scan with reduced filters.
+
+            // Removes current highest scan mode requested and sets the next highest scan mode.
+            if (removedRecord.getScanRequest().getScanMode() == mScanMode) {
+                Log.v(TAG, "DiscoveryProviderManager starts to find the new highest scan mode "
+                        + "because the highest scan mode listener was unregistered.");
+                @ScanRequest.ScanMode int highestScanModeRequested = ScanRequest.SCAN_MODE_NO_POWER;
+                // find the next highest scan mode;
+                for (ScanListenerRecord record : mScanTypeScanListenerRecordMap.values()) {
+                    @ScanRequest.ScanMode int scanMode = record.getScanRequest().getScanMode();
+                    if (scanMode > highestScanModeRequested) {
+                        highestScanModeRequested = scanMode;
+                    }
+                }
+                if (mScanMode != highestScanModeRequested) {
+                    mScanMode = highestScanModeRequested;
+                    invalidateProviderScanMode();
+                }
+            }
+        }
+    }
+
+    /**
+     * Query offload capability in a device.
+     */
+    public void queryOffloadCapability(IOffloadCallback callback) {
+        mChreDiscoveryProvider.queryOffloadCapability(callback);
+    }
+
+    /**
+     * @return {@code null} when all providers are initializing
+     * {@code false} when fail to start all the providers
+     * {@code true} when any one of the provider starts successfully
+     */
+    @VisibleForTesting
+    @Nullable
+    Boolean startProviders(ScanRequest scanRequest) {
+        if (!scanRequest.isBleEnabled()) {
+            Log.w(TAG, "failed to start any provider because client disabled BLE");
+            return false;
+        }
+        List<ScanFilter> scanFilters = getPresenceScanFilters();
+        boolean chreOnly = isChreOnly(scanFilters);
+        Boolean chreAvailable = mChreDiscoveryProvider.available();
+        if (chreAvailable == null) {
+            if (chreOnly) {
+                Log.w(TAG, "client wants CHRE only and Nearby service is still querying CHRE"
+                        + " status");
+                return null;
+            }
+            startBleProvider(scanFilters);
+            return true;
+        }
+
+        if (!chreAvailable) {
+            if (chreOnly) {
+                Log.w(TAG, "failed to start any provider because client wants CHRE only and CHRE"
+                        + " is not available");
+                return false;
+            }
+            startBleProvider(scanFilters);
+            return true;
+        }
+
+        if (scanRequest.getScanType() == SCAN_TYPE_NEARBY_PRESENCE) {
+            startChreProvider(scanFilters);
+            return true;
+        }
+
+        startBleProvider(scanFilters);
+        return true;
+    }
+
+    private void startBleProvider(List<ScanFilter> scanFilters) {
+        if (!mBleDiscoveryProvider.getController().isStarted()) {
+            Log.d(TAG, "DiscoveryProviderManager starts Ble scanning.");
+            mBleDiscoveryProvider.getController().setListener(this);
+            mBleDiscoveryProvider.getController().setProviderScanMode(mScanMode);
+            mBleDiscoveryProvider.getController().setProviderScanFilters(scanFilters);
+            mBleDiscoveryProvider.getController().start();
+        }
+    }
+
+    @VisibleForTesting
+    void startChreProvider(List<ScanFilter> scanFilters) {
+        Log.d(TAG, "DiscoveryProviderManager starts CHRE scanning.");
+        mChreDiscoveryProvider.getController().setProviderScanFilters(scanFilters);
+        mChreDiscoveryProvider.getController().setProviderScanMode(mScanMode);
+        mChreDiscoveryProvider.getController().start();
+    }
+
+    private List<ScanFilter> getPresenceScanFilters() {
+        synchronized (mLock) {
+            List<ScanFilter> scanFilters = new ArrayList();
+            for (IBinder listenerBinder : mScanTypeScanListenerRecordMap.keySet()) {
+                ScanListenerRecord record = mScanTypeScanListenerRecordMap.get(listenerBinder);
+                List<ScanFilter> presenceFilters =
+                        record.getScanRequest().getScanFilters().stream()
+                                .filter(
+                                        scanFilter ->
+                                                scanFilter.getType() == SCAN_TYPE_NEARBY_PRESENCE)
+                                .collect(Collectors.toList());
+                scanFilters.addAll(presenceFilters);
+            }
+            return scanFilters;
+        }
+    }
+
+    private void stopProviders() {
+        stopBleProvider();
+        stopChreProvider();
+    }
+
+    private void stopBleProvider() {
+        mBleDiscoveryProvider.getController().stop();
+    }
+
+    @VisibleForTesting
+    protected void stopChreProvider() {
+        mChreDiscoveryProvider.getController().stop();
+    }
+
+    @VisibleForTesting
+    void invalidateProviderScanMode() {
+        if (mBleDiscoveryProvider.getController().isStarted()) {
+            mBleDiscoveryProvider.getController().setProviderScanMode(mScanMode);
+        } else {
+            Log.d(
+                    TAG,
+                    "Skip invalidating BleDiscoveryProvider scan mode because the provider not "
+                            + "started.");
+        }
+    }
+
+    @VisibleForTesting
+    static class ScanListenerRecord {
+
+        private final ScanRequest mScanRequest;
+
+        private final IScanListener mScanListener;
+
+        private final CallerIdentity mCallerIdentity;
+
+        private final ScanListenerDeathRecipient mDeathRecipient;
+
+        ScanListenerRecord(ScanRequest scanRequest, IScanListener iScanListener,
+                CallerIdentity callerIdentity, ScanListenerDeathRecipient deathRecipient) {
+            mScanListener = iScanListener;
+            mScanRequest = scanRequest;
+            mCallerIdentity = callerIdentity;
+            mDeathRecipient = deathRecipient;
+        }
+
+        IScanListener getScanListener() {
+            return mScanListener;
+        }
+
+        ScanRequest getScanRequest() {
+            return mScanRequest;
+        }
+
+        CallerIdentity getCallerIdentity() {
+            return mCallerIdentity;
+        }
+
+        ScanListenerDeathRecipient getDeathRecipient() {
+            return mDeathRecipient;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            if (other instanceof ScanListenerRecord) {
+                ScanListenerRecord otherScanListenerRecord = (ScanListenerRecord) other;
+                return Objects.equals(mScanRequest, otherScanListenerRecord.mScanRequest)
+                        && Objects.equals(mScanListener, otherScanListenerRecord.mScanListener);
+            }
+            return false;
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(mScanListener, mScanRequest);
+        }
+    }
+
+    /**
+     * Class to make listener unregister after the binder is dead.
+     */
+    public class ScanListenerDeathRecipient implements IBinder.DeathRecipient {
+        public IScanListener listener;
+
+        ScanListenerDeathRecipient(IScanListener listener) {
+            this.listener = listener;
+        }
+
+        @Override
+        public void binderDied() {
+            Log.d(TAG, "Binder is dead - unregistering scan listener");
+            unregisterScanListener(listener);
+        }
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/managers/ListenerMultiplexer.java b/nearby/service/java/com/android/server/nearby/managers/ListenerMultiplexer.java
new file mode 100644
index 0000000..a6a9388
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/ListenerMultiplexer.java
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import static com.android.server.nearby.NearbyService.TAG;
+
+import android.annotation.NonNull;
+import android.os.IBinder;
+import android.util.ArrayMap;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.server.nearby.managers.registration.BinderListenerRegistration;
+import com.android.server.nearby.managers.registration.BinderListenerRegistration.ListenerOperation;
+
+import java.util.Collection;
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * A simplified class based on {@link com.android.server.location.listeners.ListenerMultiplexer}.
+ * It is a base class to multiplex broadcast and discovery events to multiple listener
+ * registrations. Every listener is represented by a registration object which stores all required
+ * state for a listener.
+ * Registrations will be merged to one request for the service to operate.
+ *
+ * @param <TListener>           callback type for clients
+ * @param <TRegistration>       child of {@link BinderListenerRegistration}
+ * @param <TMergedRegistration> merged registration type
+ */
+public abstract class ListenerMultiplexer<TListener,
+        TRegistration extends BinderListenerRegistration<TListener>, TMergedRegistration> {
+
+    /**
+     * The lock object used by the multiplexer. Acquiring this lock allows for multiple operations
+     * on the multiplexer to be completed atomically. Otherwise, it is not required to hold this
+     * lock. This lock is held while invoking all lifecycle callbacks on both the multiplexer and
+     * any registrations.
+     */
+    public final Object mMultiplexerLock = new Object();
+
+    @GuardedBy("mMultiplexerLock")
+    final ArrayMap<IBinder, TRegistration> mRegistrations = new ArrayMap<>();
+
+    // this is really @NonNull in many ways, but we explicitly null this out to allow for GC when
+    // not
+    // in use, so we can't annotate with @NonNull
+    @GuardedBy("mMultiplexerLock")
+    public TMergedRegistration mMerged;
+
+    /**
+     * Invoked when the multiplexer goes from having no registrations to having some registrations.
+     * This is a convenient entry point for registering listeners, etc, which only need to be
+     * present
+     * while there are any registrations. Invoked while holding the multiplexer's internal lock.
+     */
+    @GuardedBy("mMultiplexerLock")
+    public void onRegister() {
+        Log.v(TAG, "ListenerMultiplexer registered.");
+    }
+
+    /**
+     * Invoked when the multiplexer goes from having some registrations to having no registrations.
+     * This is a convenient entry point for unregistering listeners, etc, which only need to be
+     * present while there are any registrations. Invoked while holding the multiplexer's internal
+     * lock.
+     */
+    @GuardedBy("mMultiplexerLock")
+    public void onUnregister() {
+        Log.v(TAG, "ListenerMultiplexer unregistered.");
+    }
+
+    /**
+     * Puts a new registration with the given key, replacing any previous registration under the
+     * same key. This method cannot be called to put a registration re-entrantly.
+     */
+    public final void putRegistration(@NonNull IBinder key, @NonNull TRegistration registration) {
+        Objects.requireNonNull(key);
+        Objects.requireNonNull(registration);
+        synchronized (mMultiplexerLock) {
+            boolean wasEmpty = mRegistrations.isEmpty();
+
+            int index = mRegistrations.indexOfKey(key);
+            if (index > 0) {
+                BinderListenerRegistration<TListener> oldRegistration = mRegistrations.valueAt(
+                        index);
+                oldRegistration.onUnregister();
+                mRegistrations.setValueAt(index, registration);
+            } else {
+                mRegistrations.put(key, registration);
+            }
+
+            registration.onRegister();
+            onRegistrationsUpdated();
+            if (wasEmpty) {
+                onRegister();
+            }
+        }
+    }
+
+    /**
+     * Removes the registration with the given key.
+     */
+    public final void removeRegistration(IBinder key) {
+        synchronized (mMultiplexerLock) {
+            int index = mRegistrations.indexOfKey(key);
+            if (index < 0) {
+                return;
+            }
+
+            removeRegistration(index);
+        }
+    }
+
+    @GuardedBy("mMultiplexerLock")
+    private void removeRegistration(int index) {
+        TRegistration registration = mRegistrations.valueAt(index);
+
+        registration.onUnregister();
+        mRegistrations.removeAt(index);
+
+        onRegistrationsUpdated();
+
+        if (mRegistrations.isEmpty()) {
+            onUnregister();
+        }
+    }
+
+    /**
+     * Invoked when a registration is added, removed, or replaced. Invoked while holding the
+     * multiplexer's internal lock.
+     */
+    @GuardedBy("mMultiplexerLock")
+    public final void onRegistrationsUpdated() {
+        TMergedRegistration newMerged = mergeRegistrations(mRegistrations.values());
+        if (newMerged.equals(mMerged)) {
+            return;
+        }
+        mMerged = newMerged;
+        onMergedRegistrationsUpdated();
+    }
+
+    /**
+     * Called in order to generate a merged registration from the given set of active registrations.
+     * The list of registrations will never be empty. If the resulting merged registration is equal
+     * to the currently registered merged registration, nothing further will happen. If the merged
+     * registration differs,{@link #onMergedRegistrationsUpdated()} will be invoked with the new
+     * merged registration so that the backing service can be updated.
+     */
+    @GuardedBy("mMultiplexerLock")
+    public abstract TMergedRegistration mergeRegistrations(
+            @NonNull Collection<TRegistration> registrations);
+
+    /**
+     * The operation that the manager wants to handle when there is an update for the merged
+     * registration.
+     */
+    @GuardedBy("mMultiplexerLock")
+    public abstract void onMergedRegistrationsUpdated();
+
+    protected final void deliverToListeners(
+            Function<TRegistration, ListenerOperation<TListener>> function) {
+        synchronized (mMultiplexerLock) {
+            final int size = mRegistrations.size();
+            for (int i = 0; i < size; i++) {
+                TRegistration registration = mRegistrations.valueAt(i);
+                BinderListenerRegistration.ListenerOperation<TListener> operation = function.apply(
+                        registration);
+                if (operation != null) {
+                    registration.executeOperation(operation);
+                }
+            }
+        }
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/managers/MergedDiscoveryRequest.java b/nearby/service/java/com/android/server/nearby/managers/MergedDiscoveryRequest.java
new file mode 100644
index 0000000..dcfb602
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/MergedDiscoveryRequest.java
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import android.annotation.IntDef;
+import android.nearby.ScanFilter;
+import android.nearby.ScanRequest;
+import android.util.ArraySet;
+
+import com.google.common.collect.ImmutableSet;
+
+import java.util.Collection;
+import java.util.Set;
+
+/** Internal discovery request to {@link DiscoveryProviderManager} and providers */
+public class MergedDiscoveryRequest {
+
+    private static final MergedDiscoveryRequest EMPTY_REQUEST = new MergedDiscoveryRequest(
+            /* scanMode= */ ScanRequest.SCAN_MODE_NO_POWER,
+            /* scanTypes= */ ImmutableSet.of(),
+            /* actions= */ ImmutableSet.of(),
+            /* scanFilters= */ ImmutableSet.of(),
+            /* mediums= */ ImmutableSet.of());
+    @ScanRequest.ScanMode
+    private final int mScanMode;
+    private final Set<Integer> mScanTypes;
+    private final Set<Integer> mActions;
+    private final Set<ScanFilter> mScanFilters;
+    private final Set<Integer> mMediums;
+
+    private MergedDiscoveryRequest(@ScanRequest.ScanMode int scanMode, Set<Integer> scanTypes,
+            Set<Integer> actions, Set<ScanFilter> scanFilters, Set<Integer> mediums) {
+        mScanMode = scanMode;
+        mScanTypes = scanTypes;
+        mActions = actions;
+        mScanFilters = scanFilters;
+        mMediums = mediums;
+    }
+
+    /**
+     * Returns an empty discovery request.
+     *
+     * <p>The empty request is used as the default request when the discovery engine is enabled,
+     * but
+     * there is no request yet. It's also used to notify the discovery engine all clients have
+     * removed
+     * their requests.
+     */
+    public static MergedDiscoveryRequest empty() {
+        return EMPTY_REQUEST;
+    }
+
+    /** Returns the priority of the request */
+    @ScanRequest.ScanMode
+    public final int getScanMode() {
+        return mScanMode;
+    }
+
+    /** Returns all requested scan types. */
+    public ImmutableSet<Integer> getScanTypes() {
+        return ImmutableSet.copyOf(mScanTypes);
+    }
+
+    /** Returns the actions of the request */
+    public ImmutableSet<Integer> getActions() {
+        return ImmutableSet.copyOf(mActions);
+    }
+
+    /** Returns the scan filters of the request */
+    public ImmutableSet<ScanFilter> getScanFilters() {
+        return ImmutableSet.copyOf(mScanFilters);
+    }
+
+    /** Returns the enabled scan mediums */
+    public ImmutableSet<Integer> getMediums() {
+        return ImmutableSet.copyOf(mMediums);
+    }
+
+    /**
+     * The medium where the broadcast request should be sent.
+     *
+     * @hide
+     */
+    @IntDef({Medium.BLE})
+    public @interface Medium {
+        int BLE = 1;
+    }
+
+    /** Builder for {@link MergedDiscoveryRequest}. */
+    public static class Builder {
+        private final Set<Integer> mScanTypes;
+        private final Set<Integer> mActions;
+        private final Set<ScanFilter> mScanFilters;
+        private final Set<Integer> mMediums;
+        @ScanRequest.ScanMode
+        private int mScanMode;
+
+        public Builder() {
+            mScanMode = ScanRequest.SCAN_MODE_NO_POWER;
+            mScanTypes = new ArraySet<>();
+            mActions = new ArraySet<>();
+            mScanFilters = new ArraySet<>();
+            mMediums = new ArraySet<>();
+        }
+
+        /**
+         * Sets the priority for the engine request.
+         */
+        public Builder setScanMode(@ScanRequest.ScanMode int scanMode) {
+            mScanMode = scanMode;
+            return this;
+        }
+
+        /**
+         * Adds scan type to the request.
+         */
+        public Builder addScanType(@ScanRequest.ScanType int type) {
+            mScanTypes.add(type);
+            return this;
+        }
+
+        /** Add actions to the request. */
+        public Builder addActions(Collection<Integer> actions) {
+            mActions.addAll(actions);
+            return this;
+        }
+
+        /** Add actions to the request. */
+        public Builder addScanFilters(Collection<ScanFilter> scanFilters) {
+            mScanFilters.addAll(scanFilters);
+            return this;
+        }
+
+        /**
+         * Add mediums to the request.
+         */
+        public Builder addMedium(@Medium int medium) {
+            mMediums.add(medium);
+            return this;
+        }
+
+        /** Builds an instance of {@link MergedDiscoveryRequest}. */
+        public MergedDiscoveryRequest build() {
+            return new MergedDiscoveryRequest(mScanMode, mScanTypes, mActions, mScanFilters,
+                    mMediums);
+        }
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/managers/registration/BinderListenerRegistration.java b/nearby/service/java/com/android/server/nearby/managers/registration/BinderListenerRegistration.java
new file mode 100644
index 0000000..4aaa08f
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/registration/BinderListenerRegistration.java
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers.registration;
+
+import static com.android.server.nearby.NearbyService.TAG;
+
+import android.annotation.Nullable;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.util.Log;
+
+import com.android.server.nearby.managers.ListenerMultiplexer;
+
+import java.util.NoSuchElementException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A listener registration object which holds data associated with the listener, such as an optional
+ * request, and an executor responsible for listener invocations. Key is the IBinder.
+ *
+ * @param <TListener> listener for the callback
+ */
+public abstract class BinderListenerRegistration<TListener> implements IBinder.DeathRecipient {
+
+    private final AtomicBoolean mRemoved = new AtomicBoolean(false);
+    private final Executor mExecutor;
+    private final Object mListenerLock = new Object();
+    @Nullable
+    TListener mListener;
+    @Nullable
+    private final IBinder mKey;
+
+    public BinderListenerRegistration(IBinder key, Executor executor, TListener listener) {
+        this.mKey = key;
+        this.mExecutor = executor;
+        this.mListener = listener;
+    }
+
+    /**
+     * Must be implemented to return the
+     * {@link com.android.server.nearby.managers.ListenerMultiplexer} this registration is
+     * registered
+     * with. Often this is easiest to accomplish by defining registration subclasses as non-static
+     * inner classes of the multiplexer they are to be used with.
+     */
+    public abstract ListenerMultiplexer<TListener, ?
+            extends BinderListenerRegistration<TListener>, ?> getOwner();
+
+    public final IBinder getBinder() {
+        return mKey;
+    }
+
+    public final Executor getExecutor() {
+        return mExecutor;
+    }
+
+    /**
+     * Called when the registration is put in the Multiplexer.
+     */
+    public void onRegister() {
+        try {
+            getBinder().linkToDeath(this, 0);
+        } catch (RemoteException e) {
+            remove();
+        }
+    }
+
+    /**
+     * Called when the registration is removed in the Multiplexer.
+     */
+    public void onUnregister() {
+        this.mListener = null;
+        try {
+            getBinder().unlinkToDeath(this, 0);
+        } catch (NoSuchElementException e) {
+            Log.w(TAG, "failed to unregister binder death listener", e);
+        }
+    }
+
+    /**
+     * Removes this registration. All pending listener invocations will fail.
+     *
+     * <p>Does nothing if invoked before {@link #onRegister()} or after {@link #onUnregister()}.
+     */
+    public final void remove() {
+        IBinder key = mKey;
+        if (key != null && !mRemoved.getAndSet(true)) {
+            getOwner().removeRegistration(key);
+        }
+    }
+
+    @Override
+    public void binderDied() {
+        remove();
+    }
+
+    /**
+     * May be overridden by subclasses to handle listener operation failures. The default behavior
+     * is
+     * to further propagate any exceptions. Will always be invoked on the executor thread.
+     */
+    protected void onOperationFailure(Exception exception) {
+        throw new AssertionError(exception);
+    }
+
+    /**
+     * Executes the given listener operation on the registration executor, invoking {@link
+     * #onOperationFailure(Exception)} in case the listener operation fails. If the registration is
+     * removed prior to the operation running, the operation is considered canceled. If a null
+     * operation is supplied, nothing happens.
+     */
+    public final void executeOperation(@Nullable ListenerOperation<TListener> operation) {
+        if (operation == null) {
+            return;
+        }
+
+        synchronized (mListenerLock) {
+            if (mListener == null) {
+                return;
+            }
+
+            AtomicBoolean complete = new AtomicBoolean(false);
+            mExecutor.execute(() -> {
+                TListener listener;
+                synchronized (mListenerLock) {
+                    listener = mListener;
+                }
+
+                Exception failure = null;
+                if (listener != null) {
+                    try {
+                        operation.operate(listener);
+                    } catch (Exception e) {
+                        if (e instanceof RuntimeException) {
+                            throw (RuntimeException) e;
+                        } else {
+                            failure = e;
+                        }
+                    }
+                }
+
+                operation.onComplete(failure == null);
+                complete.set(true);
+
+                if (failure != null) {
+                    onOperationFailure(failure);
+                }
+            });
+            operation.onScheduled(complete.get());
+        }
+    }
+
+    /**
+     * An listener operation to perform.
+     *
+     * @param <ListenerT> listener type
+     */
+    public interface ListenerOperation<ListenerT> {
+
+        /**
+         * Invoked after the operation has been scheduled for execution. The {@code complete}
+         * argument
+         * will be true if {@link #onComplete(boolean)} was invoked prior to this callback (such as
+         * if
+         * using a direct executor), or false if {@link #onComplete(boolean)} will be invoked after
+         * this
+         * callback. This method is always invoked on the calling thread.
+         */
+        default void onScheduled(boolean complete) {
+        }
+
+        /**
+         * Invoked to perform an operation on the given listener. This method is always invoked on
+         * the
+         * executor thread. If this method throws a checked exception, the operation will fail and
+         * result in {@link #onOperationFailure(Exception)} being invoked. If this method throws an
+         * unchecked exception, this propagates normally and should result in a crash.
+         */
+        void operate(ListenerT listener) throws Exception;
+
+        /**
+         * Invoked after the operation is complete. The {@code success} argument will be true if
+         * the
+         * operation completed without throwing any exceptions, and false otherwise (such as if the
+         * operation was canceled prior to executing, or if it threw an exception). This invocation
+         * may
+         * happen either before or after (but never during) the invocation of {@link
+         * #onScheduled(boolean)}. This method is always invoked on the executor thread.
+         */
+        default void onComplete(boolean success) {
+        }
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/managers/registration/DiscoveryRegistration.java b/nearby/service/java/com/android/server/nearby/managers/registration/DiscoveryRegistration.java
new file mode 100644
index 0000000..bef319ec
--- /dev/null
+++ b/nearby/service/java/com/android/server/nearby/managers/registration/DiscoveryRegistration.java
@@ -0,0 +1,363 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers.registration;
+
+import static android.nearby.ScanRequest.SCAN_TYPE_NEARBY_PRESENCE;
+
+import static com.android.server.nearby.NearbyService.TAG;
+
+import android.annotation.IntDef;
+import android.annotation.Nullable;
+import android.app.AppOpsManager;
+import android.nearby.IScanListener;
+import android.nearby.NearbyDeviceParcelable;
+import android.nearby.PresenceScanFilter;
+import android.nearby.ScanCallback;
+import android.nearby.ScanFilter;
+import android.nearby.ScanRequest;
+import android.util.ArrayMap;
+import android.util.ArraySet;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.nearby.common.CancelableAlarm;
+import com.android.server.nearby.managers.ListenerMultiplexer;
+import com.android.server.nearby.managers.MergedDiscoveryRequest;
+import com.android.server.nearby.presence.PresenceDiscoveryResult;
+import com.android.server.nearby.util.identity.CallerIdentity;
+import com.android.server.nearby.util.permissions.DiscoveryPermissions;
+
+import com.google.common.collect.ImmutableSet;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.stream.Collectors;
+
+/**
+ * Class responsible for all client based operations. Each {@link DiscoveryRegistration} is for one
+ * valid unique {@link android.nearby.NearbyManager#startScan(ScanRequest, Executor, ScanCallback)}
+ */
+public class DiscoveryRegistration extends BinderListenerRegistration<IScanListener> {
+
+    /**
+     * Timeout before a previous discovered device is reported as lost.
+     */
+    @VisibleForTesting
+    static final int ON_LOST_TIME_OUT_MS = 10000;
+    /** Lock for registration operations. */
+    final Object mMultiplexerLock;
+    private final ListenerMultiplexer<IScanListener, DiscoveryRegistration, MergedDiscoveryRequest>
+            mOwner;
+    private final AppOpsManager mAppOpsManager;
+    /** Presence devices that are currently discovered, and not lost yet. */
+    @GuardedBy("mMultiplexerLock")
+    private final Map<Long, NearbyDeviceParcelable> mDiscoveredDevices;
+    /** A map of deviceId and alarms for reporting device lost. */
+    @GuardedBy("mMultiplexerLock")
+    private final Map<Long, DeviceOnLostAlarm> mDiscoveryOnLostAlarmPerDevice = new ArrayMap<>();
+    /**
+     * The single thread executor to run {@link CancelableAlarm} to report
+     * {@link NearbyDeviceParcelable} on lost after timeout.
+     */
+    private final ScheduledExecutorService mAlarmExecutor =
+            Executors.newSingleThreadScheduledExecutor();
+    private final ScanRequest mScanRequest;
+    private final CallerIdentity mCallerIdentity;
+
+    public DiscoveryRegistration(
+            ListenerMultiplexer<IScanListener, DiscoveryRegistration, MergedDiscoveryRequest> owner,
+            ScanRequest scanRequest, IScanListener scanListener, Executor executor,
+            CallerIdentity callerIdentity, Object multiplexerLock, AppOpsManager appOpsManager) {
+        super(scanListener.asBinder(), executor, scanListener);
+        mOwner = owner;
+        mListener = scanListener;
+        mScanRequest = scanRequest;
+        mCallerIdentity = callerIdentity;
+        mMultiplexerLock = multiplexerLock;
+        mDiscoveredDevices = new ArrayMap<>();
+        mAppOpsManager = appOpsManager;
+    }
+
+    /**
+     * Gets the scan request.
+     */
+    public ScanRequest getScanRequest() {
+        return mScanRequest;
+    }
+
+    /**
+     * Gets the actions from the scan filter(s).
+     */
+    public Set<Integer> getActions() {
+        Set<Integer> result = new ArraySet<>();
+        List<ScanFilter> filters = mScanRequest.getScanFilters();
+        for (ScanFilter filter : filters) {
+            if (filter instanceof PresenceScanFilter) {
+                result.addAll(((PresenceScanFilter) filter).getPresenceActions());
+            }
+        }
+        return ImmutableSet.copyOf(result);
+    }
+
+    /**
+     * Gets all the filters that are for Nearby Presence.
+     */
+    public Set<ScanFilter> getPresenceScanFilters() {
+        Set<ScanFilter> result = new ArraySet<>();
+        List<ScanFilter> filters = mScanRequest.getScanFilters();
+        for (ScanFilter filter : filters) {
+            if (filter.getType() == SCAN_TYPE_NEARBY_PRESENCE) {
+                result.add(filter);
+            }
+        }
+        return ImmutableSet.copyOf(result);
+    }
+
+    @VisibleForTesting
+    Map<Long, DeviceOnLostAlarm> getDiscoveryOnLostAlarms() {
+        synchronized (mMultiplexerLock) {
+            return mDiscoveryOnLostAlarmPerDevice;
+        }
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other instanceof DiscoveryRegistration) {
+            DiscoveryRegistration otherRegistration = (DiscoveryRegistration) other;
+            return Objects.equals(mScanRequest, otherRegistration.mScanRequest) && Objects.equals(
+                    mListener, otherRegistration.mListener);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mListener, mScanRequest);
+    }
+
+    @Override
+    public ListenerMultiplexer<
+            IScanListener, DiscoveryRegistration, MergedDiscoveryRequest> getOwner() {
+        return mOwner;
+    }
+
+    @VisibleForTesting
+    ListenerOperation<IScanListener> reportDeviceLost(NearbyDeviceParcelable device) {
+        long deviceId = device.getDeviceId();
+        return reportResult(DiscoveryResult.DEVICE_LOST, device, () -> {
+            synchronized (mMultiplexerLock) {
+                // Remove the device from reporting devices after reporting lost.
+                mDiscoveredDevices.remove(deviceId);
+                DeviceOnLostAlarm alarm = mDiscoveryOnLostAlarmPerDevice.remove(deviceId);
+                if (alarm != null) {
+                    alarm.cancel();
+                }
+            }
+        });
+    }
+
+    /**
+     * Called when there is device discovered from the server.
+     */
+    public ListenerOperation<IScanListener> onNearbyDeviceDiscovered(
+            NearbyDeviceParcelable device) {
+        if (!filterCheck(device)) {
+            Log.d(TAG, "presence filter does not match for the scanned Presence Device");
+            return null;
+        }
+        synchronized (mMultiplexerLock) {
+            long deviceId = device.getDeviceId();
+            boolean deviceReported = mDiscoveredDevices.containsKey(deviceId);
+            scheduleOnLostAlarm(device);
+            if (deviceReported) {
+                NearbyDeviceParcelable oldDevice = mDiscoveredDevices.get(deviceId);
+                if (device.equals(oldDevice)) {
+                    return null;
+                }
+                return reportUpdated(device);
+            }
+            return reportDiscovered(device);
+        }
+    }
+
+    @VisibleForTesting
+    static boolean presenceFilterMatches(NearbyDeviceParcelable device,
+            List<ScanFilter> scanFilters) {
+        if (scanFilters.isEmpty()) {
+            return true;
+        }
+        PresenceDiscoveryResult discoveryResult = PresenceDiscoveryResult.fromDevice(device);
+        for (ScanFilter scanFilter : scanFilters) {
+            PresenceScanFilter presenceScanFilter = (PresenceScanFilter) scanFilter;
+            if (discoveryResult.matches(presenceScanFilter)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Nullable
+    ListenerOperation<IScanListener> reportDiscovered(NearbyDeviceParcelable device) {
+        long deviceId = device.getDeviceId();
+        return reportResult(DiscoveryResult.DEVICE_DISCOVERED, device, () -> {
+            synchronized (mMultiplexerLock) {
+                // Add the device to discovered devices after reporting device is
+                // discovered.
+                mDiscoveredDevices.put(deviceId, device);
+                scheduleOnLostAlarm(device);
+            }
+        });
+    }
+
+    @Nullable
+    ListenerOperation<IScanListener> reportUpdated(NearbyDeviceParcelable device) {
+        long deviceId = device.getDeviceId();
+        return reportResult(DiscoveryResult.DEVICE_UPDATED, device, () -> {
+            synchronized (mMultiplexerLock) {
+                // Update the new device to discovered devices after reporting device is
+                // discovered.
+                mDiscoveredDevices.put(deviceId, device);
+                scheduleOnLostAlarm(device);
+            }
+        });
+
+    }
+
+    /** Reports an error to the client. */
+    public ListenerOperation<IScanListener> reportError(@ScanCallback.ErrorCode int errorCode) {
+        return listener -> listener.onError(errorCode);
+    }
+
+    @Nullable
+    ListenerOperation<IScanListener> reportResult(@DiscoveryResult int result,
+            NearbyDeviceParcelable device, @Nullable Runnable successReportCallback) {
+        // Report the operation to AppOps.
+        // NOTE: AppOps report has to be the last operation before delivering the result. Otherwise
+        // we may over-report when the discovery result doesn't end up being delivered.
+        if (!checkIdentity()) {
+            return reportError(ScanCallback.ERROR_PERMISSION_DENIED);
+        }
+
+        return new ListenerOperation<>() {
+
+            @Override
+            public void operate(IScanListener listener) throws Exception {
+                switch (result) {
+                    case DiscoveryResult.DEVICE_DISCOVERED:
+                        listener.onDiscovered(device);
+                        break;
+                    case DiscoveryResult.DEVICE_UPDATED:
+                        listener.onUpdated(device);
+                        break;
+                    case DiscoveryResult.DEVICE_LOST:
+                        listener.onLost(device);
+                        break;
+                }
+            }
+
+            @Override
+            public void onComplete(boolean success) {
+                if (success) {
+                    if (successReportCallback != null) {
+                        successReportCallback.run();
+                        Log.d(TAG, "Successfully delivered result to caller.");
+                    }
+                }
+            }
+        };
+    }
+
+    private boolean filterCheck(NearbyDeviceParcelable device) {
+        if (device.getScanType() != SCAN_TYPE_NEARBY_PRESENCE) {
+            return true;
+        }
+        List<ScanFilter> presenceFilters = mScanRequest.getScanFilters().stream().filter(
+                scanFilter -> scanFilter.getType() == SCAN_TYPE_NEARBY_PRESENCE).collect(
+                Collectors.toList());
+        return presenceFilterMatches(device, presenceFilters);
+    }
+
+    private boolean checkIdentity() {
+        boolean result = DiscoveryPermissions.noteDiscoveryResultDelivery(mAppOpsManager,
+                mCallerIdentity);
+        Log.v(TAG, "checkIdentity: result is " + result + " mAppOpsManager " + mAppOpsManager);
+        if (!result) {
+            Log.w(TAG, "[DiscoveryProviderManager] scan permission revoked "
+                    + "- not forwarding results for the registration.");
+        }
+        return result;
+    }
+
+    @GuardedBy("mMultiplexerLock")
+    private void scheduleOnLostAlarm(NearbyDeviceParcelable device) {
+        long deviceId = device.getDeviceId();
+        DeviceOnLostAlarm alarm = mDiscoveryOnLostAlarmPerDevice.get(deviceId);
+        if (alarm == null) {
+            alarm = new DeviceOnLostAlarm(device, mAlarmExecutor);
+            mDiscoveryOnLostAlarmPerDevice.put(deviceId, alarm);
+        }
+        alarm.start();
+        Log.d(TAG, "DiscoveryProviderManager updated state for " + device.getDeviceId());
+    }
+
+    /** Status of the discovery result. */
+    @IntDef({DiscoveryResult.DEVICE_DISCOVERED, DiscoveryResult.DEVICE_UPDATED,
+            DiscoveryResult.DEVICE_LOST})
+    public @interface DiscoveryResult {
+        int DEVICE_DISCOVERED = 0;
+        int DEVICE_UPDATED = 1;
+        int DEVICE_LOST = 2;
+    }
+
+    private class DeviceOnLostAlarm {
+
+        private static final String NAME = "DeviceOnLostAlarm";
+        private final NearbyDeviceParcelable mDevice;
+        private final ScheduledExecutorService mAlarmExecutor;
+        @Nullable
+        private CancelableAlarm mTimeoutAlarm;
+
+        DeviceOnLostAlarm(NearbyDeviceParcelable device, ScheduledExecutorService alarmExecutor) {
+            mDevice = device;
+            mAlarmExecutor = alarmExecutor;
+        }
+
+        synchronized void start() {
+            cancel();
+            this.mTimeoutAlarm = CancelableAlarm.createSingleAlarm(NAME, () -> {
+                Log.d(TAG, String.format("%s timed out after %d ms. Reporting %s on lost.", NAME,
+                        ON_LOST_TIME_OUT_MS, mDevice.getName()));
+                synchronized (mMultiplexerLock) {
+                    executeOperation(reportDeviceLost(mDevice));
+                }
+            }, ON_LOST_TIME_OUT_MS, mAlarmExecutor);
+        }
+
+        synchronized void cancel() {
+            if (mTimeoutAlarm != null) {
+                mTimeoutAlarm.cancel();
+                mTimeoutAlarm = null;
+            }
+        }
+    }
+}
diff --git a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
index 2cb9d38..c9098a6 100644
--- a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
+++ b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
@@ -44,12 +44,14 @@
 import com.android.server.nearby.injector.Injector;
 import com.android.server.nearby.presence.ExtendedAdvertisement;
 import com.android.server.nearby.presence.PresenceConstants;
+import com.android.server.nearby.util.ArrayUtils;
 import com.android.server.nearby.util.ForegroundThread;
 import com.android.server.nearby.util.encryption.CryptorImpIdentityV1;
 
 import com.google.common.annotations.VisibleForTesting;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -86,10 +88,12 @@
                 @Override
                 public void onScanResult(int callbackType, ScanResult scanResult) {
                     NearbyDeviceParcelable.Builder builder = new NearbyDeviceParcelable.Builder();
-                    builder.setMedium(NearbyDevice.Medium.BLE)
+                    String bleAddress = scanResult.getDevice().getAddress();
+                    builder.setDeviceId(bleAddress.hashCode())
+                            .setMedium(NearbyDevice.Medium.BLE)
                             .setRssi(scanResult.getRssi())
                             .setTxPower(scanResult.getTxPower())
-                            .setBluetoothAddress(scanResult.getDevice().getAddress());
+                            .setBluetoothAddress(bleAddress);
 
                     ScanRecord record = scanResult.getScanRecord();
                     if (record != null) {
@@ -300,6 +304,9 @@
                             builder.setPresenceDevice(getPresenceDevice(advertisement, deviceName,
                                     rssi));
                             builder.setEncryptionKeyTag(credential.getEncryptedMetadataKeyTag());
+                            if (!ArrayUtils.isEmpty(credential.getSecretId())) {
+                                builder.setDeviceId(Arrays.hashCode(credential.getSecretId()));
+                            }
                             return;
                         }
                     }
diff --git a/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java b/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
index aa18517..7ab0523 100644
--- a/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
+++ b/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
@@ -44,6 +44,7 @@
 
 import com.google.protobuf.ByteString;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -362,6 +363,7 @@
 
                         NearbyDeviceParcelable device =
                                 new NearbyDeviceParcelable.Builder()
+                                        .setDeviceId(Arrays.hashCode(secretId))
                                         .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                                         .setMedium(NearbyDevice.Medium.BLE)
                                         .setTxPower(filterResult.getTxPower())
diff --git a/nearby/tests/unit/src/com/android/server/nearby/NearbyServiceTest.java b/nearby/tests/unit/src/com/android/server/nearby/NearbyServiceTest.java
index 0d46d3e..90c85ab 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/NearbyServiceTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/NearbyServiceTest.java
@@ -36,6 +36,7 @@
 import android.content.Context;
 import android.nearby.IScanListener;
 import android.nearby.ScanRequest;
+import android.os.IBinder;
 import android.provider.DeviceConfig;
 
 import androidx.test.platform.app.InstrumentationRegistry;
@@ -61,10 +62,14 @@
     private IScanListener mScanListener;
     @Mock
     private AppOpsManager mMockAppOpsManager;
+    @Mock
+    private IBinder mIBinder;
 
     @Before
     public void setUp()  {
         initMocks(this);
+        when(mScanListener.asBinder()).thenReturn(mIBinder);
+
         mUiAutomation.adoptShellPermissionIdentity(
                 READ_DEVICE_CONFIG, WRITE_DEVICE_CONFIG, BLUETOOTH_PRIVILEGED);
         mContext = InstrumentationRegistry.getInstrumentation().getContext();
diff --git a/nearby/tests/unit/src/com/android/server/nearby/common/CancelableAlarmTest.java b/nearby/tests/unit/src/com/android/server/nearby/common/CancelableAlarmTest.java
index c7d3e25..719e816 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/common/CancelableAlarmTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/common/CancelableAlarmTest.java
@@ -80,14 +80,14 @@
     @Test
     public void cancelOfRunAlarmReturnsFalse() throws InterruptedException {
         TestCountDownLatch latch = new TestCountDownLatch(1);
-        long delayMillis = 1000;
+        long delayMillis = 500;
         CancelableAlarm alarm =
                 CancelableAlarm.createSingleAlarm(
                         "cancelOfRunAlarmReturnsFalse",
                         new CountDownRunnable(latch),
                         delayMillis,
                         mExecutor);
-        latch.awaitAndExpectDelay(delayMillis);
+        latch.awaitAndExpectDelay(delayMillis - 1);
 
         assertThat(alarm.cancel()).isFalse();
     }
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerLegacyTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerLegacyTest.java
new file mode 100644
index 0000000..aa0dad3
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerLegacyTest.java
@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import static android.nearby.PresenceCredential.IDENTITY_TYPE_PRIVATE;
+import static android.nearby.ScanRequest.SCAN_TYPE_NEARBY_PRESENCE;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.AppOpsManager;
+import android.content.Context;
+import android.nearby.DataElement;
+import android.nearby.IScanListener;
+import android.nearby.NearbyDeviceParcelable;
+import android.nearby.PresenceScanFilter;
+import android.nearby.PublicCredential;
+import android.nearby.ScanRequest;
+import android.os.IBinder;
+
+import com.android.server.nearby.injector.Injector;
+import com.android.server.nearby.provider.BleDiscoveryProvider;
+import com.android.server.nearby.provider.ChreCommunication;
+import com.android.server.nearby.provider.ChreDiscoveryProvider;
+import com.android.server.nearby.provider.DiscoveryProviderController;
+import com.android.server.nearby.util.identity.CallerIdentity;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/**
+ * Unit test for {@link DiscoveryProviderManagerLegacy} class.
+ */
+public class DiscoveryProviderManagerLegacyTest {
+    private static final int SCAN_MODE_CHRE_ONLY = 3;
+    private static final int DATA_TYPE_SCAN_MODE = 102;
+    private static final int UID = 1234;
+    private static final int PID = 5678;
+    private static final String PACKAGE_NAME = "android.nearby.test";
+    private static final int RSSI = -60;
+    @Mock
+    Injector mInjector;
+    @Mock
+    Context mContext;
+    @Mock
+    AppOpsManager mAppOpsManager;
+    @Mock
+    BleDiscoveryProvider mBleDiscoveryProvider;
+    @Mock
+    ChreDiscoveryProvider mChreDiscoveryProvider;
+    @Mock
+    DiscoveryProviderController mBluetoothController;
+    @Mock
+    DiscoveryProviderController mChreController;
+    @Mock
+    IScanListener mScanListener;
+    @Mock
+    CallerIdentity mCallerIdentity;
+    @Mock
+    DiscoveryProviderManagerLegacy.ScanListenerDeathRecipient mScanListenerDeathRecipient;
+    @Mock
+    IBinder mIBinder;
+    private DiscoveryProviderManagerLegacy mDiscoveryProviderManager;
+    private Map<IBinder, DiscoveryProviderManagerLegacy.ScanListenerRecord>
+            mScanTypeScanListenerRecordMap;
+
+    private static PresenceScanFilter getPresenceScanFilter() {
+        final byte[] secretId = new byte[]{1, 2, 3, 4};
+        final byte[] authenticityKey = new byte[]{0, 1, 1, 1};
+        final byte[] publicKey = new byte[]{1, 1, 2, 2};
+        final byte[] encryptedMetadata = new byte[]{1, 2, 3, 4, 5};
+        final byte[] metadataEncryptionKeyTag = new byte[]{1, 1, 3, 4, 5};
+
+        PublicCredential credential = new PublicCredential.Builder(
+                secretId, authenticityKey, publicKey, encryptedMetadata, metadataEncryptionKeyTag)
+                .setIdentityType(IDENTITY_TYPE_PRIVATE)
+                .build();
+
+        final int action = 123;
+        return new PresenceScanFilter.Builder()
+                .addCredential(credential)
+                .setMaxPathLoss(RSSI)
+                .addPresenceAction(action)
+                .build();
+    }
+
+    private static PresenceScanFilter getChreOnlyPresenceScanFilter() {
+        final byte[] secretId = new byte[]{1, 2, 3, 4};
+        final byte[] authenticityKey = new byte[]{0, 1, 1, 1};
+        final byte[] publicKey = new byte[]{1, 1, 2, 2};
+        final byte[] encryptedMetadata = new byte[]{1, 2, 3, 4, 5};
+        final byte[] metadataEncryptionKeyTag = new byte[]{1, 1, 3, 4, 5};
+
+        PublicCredential credential = new PublicCredential.Builder(
+                secretId, authenticityKey, publicKey, encryptedMetadata, metadataEncryptionKeyTag)
+                .setIdentityType(IDENTITY_TYPE_PRIVATE)
+                .build();
+
+        final int action = 123;
+        DataElement scanModeElement = new DataElement(DATA_TYPE_SCAN_MODE,
+                new byte[]{SCAN_MODE_CHRE_ONLY});
+        return new PresenceScanFilter.Builder()
+                .addCredential(credential)
+                .setMaxPathLoss(RSSI)
+                .addPresenceAction(action)
+                .addExtendedProperty(scanModeElement)
+                .build();
+    }
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        when(mInjector.getAppOpsManager()).thenReturn(mAppOpsManager);
+        when(mBleDiscoveryProvider.getController()).thenReturn(mBluetoothController);
+        when(mChreDiscoveryProvider.getController()).thenReturn(mChreController);
+
+        mScanTypeScanListenerRecordMap = new HashMap<>();
+        mDiscoveryProviderManager =
+                new DiscoveryProviderManagerLegacy(mContext, mInjector,
+                        mBleDiscoveryProvider,
+                        mChreDiscoveryProvider,
+                        mScanTypeScanListenerRecordMap);
+        mCallerIdentity = CallerIdentity
+                .forTest(UID, PID, PACKAGE_NAME, /* attributionTag= */ null);
+    }
+
+    @Test
+    public void testOnNearbyDeviceDiscovered() {
+        NearbyDeviceParcelable nearbyDeviceParcelable = new NearbyDeviceParcelable.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .build();
+        mDiscoveryProviderManager.onNearbyDeviceDiscovered(nearbyDeviceParcelable);
+    }
+
+    @Test
+    public void testInvalidateProviderScanMode() {
+        mDiscoveryProviderManager.invalidateProviderScanMode();
+    }
+
+    @Test
+    public void testStartProviders_chreOnlyChreAvailable_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(true);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getChreOnlyPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isTrue();
+    }
+
+    @Test
+    public void testStartProviders_chreOnlyChreAvailable_multipleFilters_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(true);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getChreOnlyPresenceScanFilter())
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isTrue();
+    }
+
+    @Test
+    public void testStartProviders_chreOnlyChreUnavailable_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(false);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getChreOnlyPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isFalse();
+    }
+
+    @Test
+    public void testStartProviders_notChreOnlyChreAvailable_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(true);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isTrue();
+    }
+
+    @Test
+    public void testStartProviders_notChreOnlyChreUnavailable_bleProviderStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(false);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, atLeastOnce()).start();
+        assertThat(start).isTrue();
+    }
+
+    @Test
+    public void testStartProviders_chreOnlyChreUndetermined_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(null);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getChreOnlyPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isNull();
+    }
+
+    @Test
+    public void testStartProviders_notChreOnlyChreUndetermined_bleProviderStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(null);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, atLeastOnce()).start();
+        assertThat(start).isTrue();
+    }
+
+    @Test
+    public void test_stopChreProvider_clearFilters() throws Exception {
+        // Cannot use mocked ChreDiscoveryProvider,
+        // so we cannot use class variable mDiscoveryProviderManager
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        DiscoveryProviderManagerLegacy manager =
+                new DiscoveryProviderManagerLegacy(mContext, mInjector,
+                        mBleDiscoveryProvider,
+                        new ChreDiscoveryProvider(
+                                mContext,
+                                new ChreCommunication(mInjector, mContext, executor), executor),
+                        mScanTypeScanListenerRecordMap);
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(
+                        scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        manager.startChreProvider(List.of(getPresenceScanFilter()));
+        // This is an asynchronized process. The filters will be set in executor thread. So we need
+        // to wait for some time to get the correct result.
+        Thread.sleep(200);
+
+        assertThat(manager.mChreDiscoveryProvider.getController().isStarted())
+                .isTrue();
+        assertThat(manager.mChreDiscoveryProvider.getFiltersLocked()).isNotNull();
+
+        manager.stopChreProvider();
+        Thread.sleep(200);
+        // The filters should be cleared right after.
+        assertThat(manager.mChreDiscoveryProvider.getController().isStarted())
+                .isFalse();
+        assertThat(manager.mChreDiscoveryProvider.getFiltersLocked()).isEmpty();
+    }
+
+    @Test
+    public void test_restartChreProvider() throws Exception {
+        // Cannot use mocked ChreDiscoveryProvider,
+        // so we cannot use class variable mDiscoveryProviderManager
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        DiscoveryProviderManagerLegacy manager =
+                new DiscoveryProviderManagerLegacy(mContext, mInjector,
+                        mBleDiscoveryProvider,
+                        new ChreDiscoveryProvider(
+                                mContext,
+                                new ChreCommunication(mInjector, mContext, executor), executor),
+                        mScanTypeScanListenerRecordMap);
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManagerLegacy.ScanListenerRecord record =
+                new DiscoveryProviderManagerLegacy.ScanListenerRecord(scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        manager.startChreProvider(List.of(getPresenceScanFilter()));
+        // This is an asynchronized process. The filters will be set in executor thread. So we need
+        // to wait for some time to get the correct result.
+        Thread.sleep(200);
+
+        assertThat(manager.mChreDiscoveryProvider.getController().isStarted())
+                .isTrue();
+        assertThat(manager.mChreDiscoveryProvider.getFiltersLocked()).isNotNull();
+
+        // We want to make sure quickly restart the provider the filters should
+        // be reset correctly.
+        // See b/255922206, there can be a race condition that filters get cleared because onStop()
+        // get executed after onStart() if they are called from different threads.
+        manager.stopChreProvider();
+        manager.mChreDiscoveryProvider.getController().setProviderScanFilters(
+                List.of(getPresenceScanFilter()));
+        manager.startChreProvider(List.of(getPresenceScanFilter()));
+        Thread.sleep(200);
+        assertThat(manager.mChreDiscoveryProvider.getController().isStarted())
+                .isTrue();
+        assertThat(manager.mChreDiscoveryProvider.getFiltersLocked()).isNotNull();
+
+        // Wait for enough time
+        Thread.sleep(1000);
+
+        assertThat(manager.mChreDiscoveryProvider.getController().isStarted())
+                .isTrue();
+        assertThat(manager.mChreDiscoveryProvider.getFiltersLocked()).isNotNull();
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerTest.java
index 542ceed..7ecf631 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/DiscoveryProviderManagerTest.java
@@ -23,6 +23,7 @@
 
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -48,10 +49,8 @@
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
 
 public class DiscoveryProviderManagerTest {
@@ -80,12 +79,9 @@
     @Mock
     CallerIdentity mCallerIdentity;
     @Mock
-    DiscoveryProviderManager.ScanListenerDeathRecipient mScanListenerDeathRecipient;
-    @Mock
     IBinder mIBinder;
+    private Executor mExecutor;
     private DiscoveryProviderManager mDiscoveryProviderManager;
-    private Map<IBinder, DiscoveryProviderManager.ScanListenerRecord>
-            mScanTypeScanListenerRecordMap;
 
     private static PresenceScanFilter getPresenceScanFilter() {
         final byte[] secretId = new byte[]{1, 2, 3, 4};
@@ -133,16 +129,16 @@
     @Before
     public void setup() {
         MockitoAnnotations.initMocks(this);
+        mExecutor = Executors.newSingleThreadExecutor();
         when(mInjector.getAppOpsManager()).thenReturn(mAppOpsManager);
         when(mBleDiscoveryProvider.getController()).thenReturn(mBluetoothController);
         when(mChreDiscoveryProvider.getController()).thenReturn(mChreController);
+        when(mScanListener.asBinder()).thenReturn(mIBinder);
 
-        mScanTypeScanListenerRecordMap = new HashMap<>();
         mDiscoveryProviderManager =
-                new DiscoveryProviderManager(mContext, mInjector,
+                new DiscoveryProviderManager(mContext, mExecutor, mInjector,
                         mBleDiscoveryProvider,
-                        mChreDiscoveryProvider,
-                        mScanTypeScanListenerRecordMap);
+                        mChreDiscoveryProvider);
         mCallerIdentity = CallerIdentity
                 .forTest(UID, PID, PACKAGE_NAME, /* attributionTag= */ null);
     }
@@ -162,55 +158,45 @@
 
     @Test
     public void testStartProviders_chreOnlyChreAvailable_bleProviderNotStarted() {
+        reset(mBluetoothController);
         when(mChreDiscoveryProvider.available()).thenReturn(true);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getChreOnlyPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, never()).start();
         assertThat(start).isTrue();
     }
 
     @Test
     public void testStartProviders_chreOnlyChreAvailable_multipleFilters_bleProviderNotStarted() {
+        reset(mBluetoothController);
         when(mChreDiscoveryProvider.available()).thenReturn(true);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
-                .addScanFilter(getChreOnlyPresenceScanFilter())
-                .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+                .addScanFilter(getChreOnlyPresenceScanFilter()).build();
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, never()).start();
         assertThat(start).isTrue();
     }
 
     @Test
     public void testStartProviders_chreOnlyChreUnavailable_bleProviderNotStarted() {
+        reset(mBluetoothController);
         when(mChreDiscoveryProvider.available()).thenReturn(false);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getChreOnlyPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, never()).start();
         assertThat(start).isFalse();
     }
@@ -218,17 +204,14 @@
     @Test
     public void testStartProviders_notChreOnlyChreAvailable_bleProviderNotStarted() {
         when(mChreDiscoveryProvider.available()).thenReturn(true);
+        reset(mBluetoothController);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, never()).start();
         assertThat(start).isTrue();
     }
@@ -236,17 +219,14 @@
     @Test
     public void testStartProviders_notChreOnlyChreUnavailable_bleProviderStarted() {
         when(mChreDiscoveryProvider.available()).thenReturn(false);
+        reset(mBluetoothController);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, atLeastOnce()).start();
         assertThat(start).isTrue();
     }
@@ -254,17 +234,14 @@
     @Test
     public void testStartProviders_chreOnlyChreUndetermined_bleProviderNotStarted() {
         when(mChreDiscoveryProvider.available()).thenReturn(null);
+        reset(mBluetoothController);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getChreOnlyPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, never()).start();
         assertThat(start).isNull();
     }
@@ -272,17 +249,14 @@
     @Test
     public void testStartProviders_notChreOnlyChreUndetermined_bleProviderStarted() {
         when(mChreDiscoveryProvider.available()).thenReturn(null);
+        reset(mBluetoothController);
 
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        mDiscoveryProviderManager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
 
-        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders();
         verify(mBluetoothController, atLeastOnce()).start();
         assertThat(start).isTrue();
     }
@@ -291,22 +265,16 @@
     public void test_stopChreProvider_clearFilters() throws Exception {
         // Cannot use mocked ChreDiscoveryProvider,
         // so we cannot use class variable mDiscoveryProviderManager
-        ExecutorService executor = Executors.newSingleThreadExecutor();
         DiscoveryProviderManager manager =
-                new DiscoveryProviderManager(mContext, mInjector,
+                new DiscoveryProviderManager(mContext, mExecutor, mInjector,
                         mBleDiscoveryProvider,
                         new ChreDiscoveryProvider(
                                 mContext,
-                                new ChreCommunication(mInjector, mContext, executor), executor),
-                        mScanTypeScanListenerRecordMap);
+                                new ChreCommunication(mInjector, mContext, mExecutor), mExecutor));
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(
-                        scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        manager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
         manager.startChreProvider(List.of(getPresenceScanFilter()));
         // This is an asynchronized process. The filters will be set in executor thread. So we need
         // to wait for some time to get the correct result.
@@ -328,21 +296,17 @@
     public void test_restartChreProvider() throws Exception {
         // Cannot use mocked ChreDiscoveryProvider,
         // so we cannot use class variable mDiscoveryProviderManager
-        ExecutorService executor = Executors.newSingleThreadExecutor();
         DiscoveryProviderManager manager =
-                new DiscoveryProviderManager(mContext, mInjector,
+                new DiscoveryProviderManager(mContext, mExecutor, mInjector,
                         mBleDiscoveryProvider,
                         new ChreDiscoveryProvider(
                                 mContext,
-                                new ChreCommunication(mInjector, mContext, executor), executor),
-                        mScanTypeScanListenerRecordMap);
+                                new ChreCommunication(mInjector, mContext, mExecutor), mExecutor));
         ScanRequest scanRequest = new ScanRequest.Builder()
                 .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
                 .addScanFilter(getPresenceScanFilter()).build();
-        DiscoveryProviderManager.ScanListenerRecord record =
-                new DiscoveryProviderManager.ScanListenerRecord(scanRequest, mScanListener,
-                        mCallerIdentity, mScanListenerDeathRecipient);
-        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+        manager.registerScanListener(scanRequest, mScanListener, mCallerIdentity);
+
         manager.startChreProvider(List.of(getPresenceScanFilter()));
         // This is an asynchronized process. The filters will be set in executor thread. So we need
         // to wait for some time to get the correct result.
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/ListenerMultiplexerTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/ListenerMultiplexerTest.java
new file mode 100644
index 0000000..104d762
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/ListenerMultiplexerTest.java
@@ -0,0 +1,302 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import android.os.IBinder;
+
+import androidx.annotation.NonNull;
+
+import com.android.server.nearby.managers.registration.BinderListenerRegistration;
+
+import com.google.common.util.concurrent.MoreExecutors;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collection;
+
+public class ListenerMultiplexerTest {
+
+    @Before
+    public void setUp() {
+        initMocks(this);
+    }
+
+    @Test
+    public void testAdd() {
+        TestMultiplexer multiplexer = new TestMultiplexer();
+
+        Runnable listener = mock(Runnable.class);
+        IBinder binder = mock(IBinder.class);
+        int value = 2;
+        multiplexer.addListener(binder, listener, value);
+
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+        Runnable listener2 = mock(Runnable.class);
+        IBinder binder2 = mock(IBinder.class);
+        int value2 = 1;
+        multiplexer.addListener(binder2, listener2, value2);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(2);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+    }
+
+    @Test
+    public void testReplace() {
+        TestMultiplexer multiplexer = new TestMultiplexer();
+        Runnable listener = mock(Runnable.class);
+        IBinder binder = mock(IBinder.class);
+        int value = 2;
+        multiplexer.addListener(binder, listener, value);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(1)).run();
+        reset(listener);
+
+        // Same key, different value
+        Runnable listener2 = mock(Runnable.class);
+        int value2 = 1;
+        multiplexer.addListener(binder, listener2, value2);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            // Should not be called again
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mOnUnregisterCalledCount).isEqualTo(0);
+            assertThat(multiplexer.mMerged).isEqualTo(value2);
+        }
+        // Run on the new listener
+        multiplexer.notifyListeners();
+        verify(listener, never()).run();
+        verify(listener2, times(1)).run();
+
+        multiplexer.removeRegistration(binder);
+
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isFalse();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mOnUnregisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(Integer.MIN_VALUE);
+        }
+    }
+
+    @Test
+    public void testRemove() {
+        TestMultiplexer multiplexer = new TestMultiplexer();
+        Runnable listener = mock(Runnable.class);
+        IBinder binder = mock(IBinder.class);
+        int value = 2;
+        multiplexer.addListener(binder, listener, value);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(1)).run();
+        reset(listener);
+
+        multiplexer.removeRegistration(binder);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isFalse();
+            assertThat(multiplexer.mMerged).isEqualTo(Integer.MIN_VALUE);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, never()).run();
+    }
+
+    @Test
+    public void testMergeMultiple() {
+        TestMultiplexer multiplexer = new TestMultiplexer();
+
+        Runnable listener = mock(Runnable.class);
+        IBinder binder = mock(IBinder.class);
+        int value = 2;
+
+        Runnable listener2 = mock(Runnable.class);
+        IBinder binder2 = mock(IBinder.class);
+        int value2 = 1;
+
+        Runnable listener3 = mock(Runnable.class);
+        IBinder binder3 = mock(IBinder.class);
+        int value3 = 5;
+
+        multiplexer.addListener(binder, listener, value);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(1)).run();
+        verify(listener2, never()).run();
+        verify(listener3, never()).run();
+
+        multiplexer.addListener(binder2, listener2, value2);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(2);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(1);
+            assertThat(multiplexer.mMerged).isEqualTo(value);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(2)).run();
+        verify(listener2, times(1)).run();
+        verify(listener3, never()).run();
+
+        multiplexer.addListener(binder3, listener3, value3);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(3);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(2);
+            assertThat(multiplexer.mMerged).isEqualTo(value3);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(3)).run();
+        verify(listener2, times(2)).run();
+        verify(listener3, times(1)).run();
+
+        multiplexer.removeRegistration(binder);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(4);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(2);
+            assertThat(multiplexer.mMerged).isEqualTo(value3);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(3)).run();
+        verify(listener2, times(3)).run();
+        verify(listener3, times(2)).run();
+
+        multiplexer.removeRegistration(binder3);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isTrue();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(5);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(3);
+            assertThat(multiplexer.mMerged).isEqualTo(value2);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(3)).run();
+        verify(listener2, times(4)).run();
+        verify(listener3, times(2)).run();
+
+        multiplexer.removeRegistration(binder2);
+        synchronized (multiplexer.mMultiplexerLock) {
+            assertThat(multiplexer.mRegistered).isFalse();
+            assertThat(multiplexer.mOnRegisterCalledCount).isEqualTo(1);
+            assertThat(multiplexer.mMergeOperationCount).isEqualTo(6);
+            assertThat(multiplexer.mMergeUpdatedCount).isEqualTo(4);
+            assertThat(multiplexer.mMerged).isEqualTo(Integer.MIN_VALUE);
+        }
+        multiplexer.notifyListeners();
+        verify(listener, times(3)).run();
+        verify(listener2, times(4)).run();
+        verify(listener3, times(2)).run();
+    }
+
+    private class TestMultiplexer extends
+            ListenerMultiplexer<Runnable, TestMultiplexer.TestListenerRegistration, Integer> {
+        int mOnRegisterCalledCount;
+        int mOnUnregisterCalledCount;
+        boolean mRegistered;
+        private int mMergeOperationCount;
+        private int mMergeUpdatedCount;
+
+        @Override
+        public void onRegister() {
+            mOnRegisterCalledCount++;
+            mRegistered = true;
+        }
+
+        @Override
+        public void onUnregister() {
+            mOnUnregisterCalledCount++;
+            mRegistered = false;
+        }
+
+        @Override
+        public Integer mergeRegistrations(
+                @NonNull Collection<TestListenerRegistration> testListenerRegistrations) {
+            mMergeOperationCount++;
+            int max = Integer.MIN_VALUE;
+            for (TestListenerRegistration registration : testListenerRegistrations) {
+                max = Math.max(max, registration.getValue());
+            }
+            return max;
+        }
+
+        @Override
+        public void onMergedRegistrationsUpdated() {
+            mMergeUpdatedCount++;
+        }
+
+        public void addListener(IBinder binder, Runnable runnable, int value) {
+            TestListenerRegistration registration = new TestListenerRegistration(binder, runnable,
+                    value);
+            putRegistration(binder, registration);
+        }
+
+        public void notifyListeners() {
+            deliverToListeners(registration -> Runnable::run);
+        }
+
+        private class TestListenerRegistration extends BinderListenerRegistration<Runnable> {
+            private final int mValue;
+
+            protected TestListenerRegistration(IBinder binder, Runnable runnable, int value) {
+                super(binder, MoreExecutors.directExecutor(), runnable);
+                mValue = value;
+            }
+
+            @Override
+            public TestMultiplexer getOwner() {
+                return TestMultiplexer.this;
+            }
+
+            public int getValue() {
+                return mValue;
+            }
+        }
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/MergedDiscoveryRequestTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/MergedDiscoveryRequestTest.java
new file mode 100644
index 0000000..9281e42
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/MergedDiscoveryRequestTest.java
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers;
+
+import static android.nearby.PresenceCredential.IDENTITY_TYPE_PRIVATE;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.nearby.DataElement;
+import android.nearby.PresenceScanFilter;
+import android.nearby.PublicCredential;
+import android.nearby.ScanFilter;
+import android.nearby.ScanRequest;
+import android.util.ArraySet;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * Unit test for {@link MergedDiscoveryRequest} class.
+ */
+public class MergedDiscoveryRequestTest {
+
+    @Test
+    public void test_addScanType() {
+        MergedDiscoveryRequest.Builder builder = new MergedDiscoveryRequest.Builder();
+        builder.addScanType(ScanRequest.SCAN_TYPE_FAST_PAIR);
+        builder.addScanType(ScanRequest.SCAN_TYPE_NEARBY_PRESENCE);
+        MergedDiscoveryRequest request = builder.build();
+
+        assertThat(request.getScanTypes()).isEqualTo(new ArraySet<>(
+                Arrays.asList(ScanRequest.SCAN_TYPE_FAST_PAIR,
+                        ScanRequest.SCAN_TYPE_NEARBY_PRESENCE)));
+    }
+
+    @Test
+    public void test_addActions() {
+        MergedDiscoveryRequest.Builder builder = new MergedDiscoveryRequest.Builder();
+        builder.addActions(new ArrayList<>(Arrays.asList(1, 2, 3)));
+        builder.addActions(new ArraySet<>(Arrays.asList(2, 3, 4)));
+        builder.addActions(new ArraySet<>(Collections.singletonList(5)));
+
+        MergedDiscoveryRequest request = builder.build();
+        assertThat(request.getActions()).isEqualTo(new ArraySet<>(new Integer[]{1, 2, 3, 4, 5}));
+    }
+
+    @Test
+    public void test_addFilters() {
+        final int rssi = -40;
+        final int action = 123;
+        final byte[] secreteId = new byte[]{1, 2, 3, 4};
+        final byte[] authenticityKey = new byte[]{0, 1, 1, 1};
+        final byte[] publicKey = new byte[]{1, 1, 2, 2};
+        final byte[] encryptedMetadata = new byte[]{1, 2, 3, 4, 5};
+        final byte[] metadataEncryptionKeyTag = new byte[]{1, 1, 3, 4, 5};
+        final int key = 3;
+        final byte[] value = new byte[]{1, 1, 1, 1};
+
+        PublicCredential mPublicCredential = new PublicCredential.Builder(secreteId,
+                authenticityKey, publicKey, encryptedMetadata,
+                metadataEncryptionKeyTag).setIdentityType(IDENTITY_TYPE_PRIVATE).build();
+        PresenceScanFilter scanFilterBuilder = new PresenceScanFilter.Builder().setMaxPathLoss(
+                rssi).addCredential(mPublicCredential).addPresenceAction(
+                action).addExtendedProperty(new DataElement(key, value)).build();
+
+        MergedDiscoveryRequest.Builder builder = new MergedDiscoveryRequest.Builder();
+        builder.addScanFilters(Collections.singleton(scanFilterBuilder));
+        MergedDiscoveryRequest request = builder.build();
+
+        Set<ScanFilter> expectedResult = new ArraySet<>();
+        expectedResult.add(scanFilterBuilder);
+        assertThat(request.getScanFilters()).isEqualTo(expectedResult);
+    }
+
+    @Test
+    public void test_addMedium() {
+        MergedDiscoveryRequest.Builder builder = new MergedDiscoveryRequest.Builder();
+        builder.addMedium(MergedDiscoveryRequest.Medium.BLE);
+        builder.addMedium(MergedDiscoveryRequest.Medium.BLE);
+        MergedDiscoveryRequest request = builder.build();
+
+        Set<Integer> expectedResult = new ArraySet<>();
+        expectedResult.add(MergedDiscoveryRequest.Medium.BLE);
+        assertThat(request.getMediums()).isEqualTo(expectedResult);
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/registration/BinderListenerRegistrationTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/registration/BinderListenerRegistrationTest.java
new file mode 100644
index 0000000..8814190
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/registration/BinderListenerRegistrationTest.java
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers.registration;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.os.IBinder;
+import android.os.RemoteException;
+
+import androidx.annotation.NonNull;
+
+import com.android.server.nearby.managers.ListenerMultiplexer;
+
+import com.google.common.util.concurrent.MoreExecutors;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collection;
+
+/**
+ * Unit test for {@link BinderListenerRegistration} class.
+ */
+public class BinderListenerRegistrationTest {
+    private TestMultiplexer mMultiplexer;
+    private boolean mOnRegisterCalled;
+    private boolean mOnUnRegisterCalled;
+
+    @Before
+    public void setUp() {
+        mMultiplexer = new TestMultiplexer();
+    }
+
+    @Test
+    public void test_addAndRemove() throws RemoteException {
+        Runnable listener = mock(Runnable.class);
+        IBinder binder = mock(IBinder.class);
+        int value = 2;
+        BinderListenerRegistration<Runnable> registration = mMultiplexer.addListener(binder,
+                listener, value);
+        // First element, onRegister should be called
+        assertThat(mOnRegisterCalled).isTrue();
+        verify(binder, times(1)).linkToDeath(any(), anyInt());
+        mMultiplexer.notifyListeners();
+        verify(listener, times(1)).run();
+        synchronized (mMultiplexer.mMultiplexerLock) {
+            assertThat(mMultiplexer.mMerged).isEqualTo(value);
+        }
+        reset(listener);
+
+        Runnable listener2 = mock(Runnable.class);
+        IBinder binder2 = mock(IBinder.class);
+        int value2 = 1;
+        BinderListenerRegistration<Runnable> registration2 = mMultiplexer.addListener(binder2,
+                listener2, value2);
+        verify(binder2, times(1)).linkToDeath(any(), anyInt());
+        mMultiplexer.notifyListeners();
+        verify(listener2, times(1)).run();
+        synchronized (mMultiplexer.mMultiplexerLock) {
+            assertThat(mMultiplexer.mMerged).isEqualTo(value);
+        }
+        reset(listener);
+        reset(listener2);
+
+        registration2.remove();
+        verify(binder2, times(1)).unlinkToDeath(any(), anyInt());
+        // Remove one element, onUnregister should NOT be called
+        assertThat(mOnUnRegisterCalled).isFalse();
+        mMultiplexer.notifyListeners();
+        verify(listener, times(1)).run();
+        synchronized (mMultiplexer.mMultiplexerLock) {
+            assertThat(mMultiplexer.mMerged).isEqualTo(value);
+        }
+        reset(listener);
+        reset(listener2);
+
+        registration.remove();
+        verify(binder, times(1)).unlinkToDeath(any(), anyInt());
+        // Remove all elements, onUnregister should NOT be called
+        assertThat(mOnUnRegisterCalled).isTrue();
+        synchronized (mMultiplexer.mMultiplexerLock) {
+            assertThat(mMultiplexer.mMerged).isEqualTo(Integer.MIN_VALUE);
+        }
+    }
+
+    private class TestMultiplexer extends
+            ListenerMultiplexer<Runnable, TestMultiplexer.TestListenerRegistration, Integer> {
+        @Override
+        public void onRegister() {
+            mOnRegisterCalled = true;
+        }
+
+        @Override
+        public void onUnregister() {
+            mOnUnRegisterCalled = true;
+        }
+
+        @Override
+        public Integer mergeRegistrations(
+                @NonNull Collection<TestListenerRegistration> testListenerRegistrations) {
+            int max = Integer.MIN_VALUE;
+            for (TestListenerRegistration registration : testListenerRegistrations) {
+                max = Math.max(max, registration.getValue());
+            }
+            return max;
+        }
+
+        @Override
+        public void onMergedRegistrationsUpdated() {
+        }
+
+        public BinderListenerRegistration<Runnable> addListener(IBinder binder, Runnable runnable,
+                int value) {
+            TestListenerRegistration registration = new TestListenerRegistration(binder, runnable,
+                    value);
+            putRegistration(binder, registration);
+            return registration;
+        }
+
+        public void notifyListeners() {
+            deliverToListeners(registration -> Runnable::run);
+        }
+
+        private class TestListenerRegistration extends BinderListenerRegistration<Runnable> {
+            private final int mValue;
+
+            protected TestListenerRegistration(IBinder binder, Runnable runnable, int value) {
+                super(binder, MoreExecutors.directExecutor(), runnable);
+                mValue = value;
+            }
+
+            @Override
+            public TestMultiplexer getOwner() {
+                return TestMultiplexer.this;
+            }
+
+            public int getValue() {
+                return mValue;
+            }
+        }
+    }
+}
diff --git a/nearby/tests/unit/src/com/android/server/nearby/managers/registration/DiscoveryRegistrationTest.java b/nearby/tests/unit/src/com/android/server/nearby/managers/registration/DiscoveryRegistrationTest.java
new file mode 100644
index 0000000..03c4f75
--- /dev/null
+++ b/nearby/tests/unit/src/com/android/server/nearby/managers/registration/DiscoveryRegistrationTest.java
@@ -0,0 +1,252 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.nearby.managers.registration;
+
+import static android.nearby.PresenceCredential.IDENTITY_TYPE_PRIVATE;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import android.app.AppOpsManager;
+import android.nearby.DataElement;
+import android.nearby.IScanListener;
+import android.nearby.NearbyDeviceParcelable;
+import android.nearby.PresenceScanFilter;
+import android.nearby.PublicCredential;
+import android.nearby.ScanCallback;
+import android.nearby.ScanFilter;
+import android.nearby.ScanRequest;
+import android.os.IBinder;
+import android.util.ArraySet;
+
+import androidx.annotation.NonNull;
+
+import com.android.server.nearby.managers.ListenerMultiplexer;
+import com.android.server.nearby.managers.MergedDiscoveryRequest;
+import com.android.server.nearby.util.identity.CallerIdentity;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.Executors;
+
+/**
+ * Unit test for {@link DiscoveryRegistration} class.
+ */
+public class DiscoveryRegistrationTest {
+    private static final int RSSI = -40;
+    private static final int ACTION = 123;
+    private static final byte[] SECRETE_ID = new byte[]{1, 2, 3, 4};
+    private static final byte[] AUTHENTICITY_KEY = new byte[]{0, 1, 1, 1};
+    private static final byte[] PUBLIC_KEY = new byte[]{1, 1, 2, 2};
+    private static final byte[] ENCRYPTED_METADATA = new byte[]{1, 2, 3, 4, 5};
+    private static final byte[] METADATA_ENCRYPTION_KEY_TAG = new byte[]{1, 1, 3, 4, 5};
+    private static final int KEY = 3;
+    private static final byte[] VALUE = new byte[]{1, 1, 1, 1};
+    private final PublicCredential mPublicCredential = new PublicCredential.Builder(SECRETE_ID,
+            AUTHENTICITY_KEY, PUBLIC_KEY, ENCRYPTED_METADATA,
+            METADATA_ENCRYPTION_KEY_TAG).setIdentityType(IDENTITY_TYPE_PRIVATE).build();
+    private final PresenceScanFilter mFilter = new PresenceScanFilter.Builder().setMaxPathLoss(
+            50).addCredential(mPublicCredential).addPresenceAction(ACTION).addExtendedProperty(
+            new DataElement(KEY, VALUE)).build();
+    private DiscoveryRegistration mDiscoveryRegistration;
+    private ScanRequest mScanRequest;
+    private TestDiscoveryManager mOwner;
+    private Object mMultiplexLock;
+    @Mock
+    private IScanListener mCallback;
+    @Mock
+    private CallerIdentity mIdentity;
+    @Mock
+    private AppOpsManager mAppOpsManager;
+    @Mock
+    private IBinder mBinder;
+
+    @Before
+    public void setUp() {
+        initMocks(this);
+        when(mCallback.asBinder()).thenReturn(mBinder);
+        when(mAppOpsManager.noteOp(eq("android:bluetooth_scan"), eq(0), eq(null), eq(null),
+                eq(null))).thenReturn(AppOpsManager.MODE_ALLOWED);
+
+        mOwner = new TestDiscoveryManager();
+        mMultiplexLock = new Object();
+        mScanRequest = new ScanRequest.Builder().setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).addScanFilter(mFilter).build();
+        mDiscoveryRegistration = new DiscoveryRegistration(mOwner, mScanRequest, mCallback,
+                Executors.newSingleThreadExecutor(), mIdentity, mMultiplexLock, mAppOpsManager);
+    }
+
+    @Test
+    public void test_getScanRequest() {
+        assertThat(mDiscoveryRegistration.getScanRequest()).isEqualTo(mScanRequest);
+    }
+
+    @Test
+    public void test_getActions() {
+        Set<Integer> result = new ArraySet<>();
+        result.add(ACTION);
+        assertThat(mDiscoveryRegistration.getActions()).isEqualTo(result);
+    }
+
+    @Test
+    public void test_getOwner() {
+        assertThat(mDiscoveryRegistration.getOwner()).isEqualTo(mOwner);
+    }
+
+    @Test
+    public void test_getPresenceScanFilters() {
+        Set<ScanFilter> result = new ArraySet<>();
+        result.add(mFilter);
+        assertThat(mDiscoveryRegistration.getPresenceScanFilters()).isEqualTo(result);
+    }
+
+    @Test
+    public void test_presenceFilterMatches_match() {
+        NearbyDeviceParcelable device = new NearbyDeviceParcelable.Builder().setDeviceId(
+                123).setName("test").setTxPower(RSSI + 1).setRssi(RSSI).setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).setAction(ACTION).setEncryptionKeyTag(
+                METADATA_ENCRYPTION_KEY_TAG).build();
+        assertThat(DiscoveryRegistration.presenceFilterMatches(device, List.of(mFilter))).isTrue();
+    }
+
+    @Test
+    public void test_presenceFilterMatches_emptyFilter() {
+        NearbyDeviceParcelable device = new NearbyDeviceParcelable.Builder().setDeviceId(
+                123).setName("test").setScanType(ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).build();
+        assertThat(DiscoveryRegistration.presenceFilterMatches(device, List.of())).isTrue();
+    }
+
+    @Test
+    public void test_presenceFilterMatches_actionNotMatch() {
+        NearbyDeviceParcelable device = new NearbyDeviceParcelable.Builder().setDeviceId(
+                12).setName("test").setRssi(RSSI).setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).setAction(5).setEncryptionKeyTag(
+                METADATA_ENCRYPTION_KEY_TAG).build();
+        assertThat(DiscoveryRegistration.presenceFilterMatches(device, List.of(mFilter))).isFalse();
+    }
+
+    @Test
+    public void test_onDiscoveredOnUpdatedCalled() throws Exception {
+        final long deviceId = 122;
+        NearbyDeviceParcelable.Builder builder = new NearbyDeviceParcelable.Builder().setDeviceId(
+                deviceId).setName("test").setTxPower(RSSI + 1).setRssi(RSSI).setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).setAction(ACTION).setEncryptionKeyTag(
+                METADATA_ENCRYPTION_KEY_TAG);
+        runOperation(mDiscoveryRegistration.onNearbyDeviceDiscovered(builder.build()));
+
+        verify(mCallback, times(1)).onDiscovered(eq(builder.build()));
+        verify(mCallback, never()).onUpdated(any());
+        verify(mCallback, never()).onLost(any());
+        verify(mCallback, never()).onError(anyInt());
+        assertThat(mDiscoveryRegistration.getDiscoveryOnLostAlarms().get(deviceId)).isNotNull();
+        reset(mCallback);
+
+        // Update RSSI
+        runOperation(
+                mDiscoveryRegistration.onNearbyDeviceDiscovered(builder.setRssi(RSSI - 1).build()));
+        verify(mCallback, never()).onDiscovered(any());
+        verify(mCallback, times(1)).onUpdated(eq(builder.build()));
+        verify(mCallback, never()).onLost(any());
+        verify(mCallback, never()).onError(anyInt());
+        assertThat(mDiscoveryRegistration.getDiscoveryOnLostAlarms().get(deviceId)).isNotNull();
+    }
+
+    @Test
+    public void test_onLost() throws Exception {
+        final long deviceId = 123;
+        NearbyDeviceParcelable device = new NearbyDeviceParcelable.Builder().setDeviceId(
+                deviceId).setName("test").setTxPower(RSSI + 1).setRssi(RSSI).setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).setAction(ACTION).setEncryptionKeyTag(
+                METADATA_ENCRYPTION_KEY_TAG).build();
+        runOperation(mDiscoveryRegistration.onNearbyDeviceDiscovered(device));
+        assertThat(mDiscoveryRegistration.getDiscoveryOnLostAlarms().get(deviceId)).isNotNull();
+        verify(mCallback, times(1)).onDiscovered(eq(device));
+        verify(mCallback, never()).onUpdated(any());
+        verify(mCallback, never()).onError(anyInt());
+        verify(mCallback, never()).onLost(any());
+        reset(mCallback);
+
+        runOperation(mDiscoveryRegistration.reportDeviceLost(device));
+
+        assertThat(mDiscoveryRegistration.getDiscoveryOnLostAlarms().get(deviceId)).isNull();
+        verify(mCallback, never()).onDiscovered(eq(device));
+        verify(mCallback, never()).onUpdated(any());
+        verify(mCallback, never()).onError(anyInt());
+        verify(mCallback, times(1)).onLost(eq(device));
+    }
+
+    @Test
+    public void test_onError() throws Exception {
+        AppOpsManager manager = mock(AppOpsManager.class);
+        when(manager.noteOp(eq("android:bluetooth_scan"), eq(0), eq(null), eq(null),
+                eq(null))).thenReturn(AppOpsManager.MODE_IGNORED);
+
+        DiscoveryRegistration r = new DiscoveryRegistration(mOwner, mScanRequest, mCallback,
+                Executors.newSingleThreadExecutor(), mIdentity, mMultiplexLock, manager);
+
+        NearbyDeviceParcelable device = new NearbyDeviceParcelable.Builder().setDeviceId(
+                123).setName("test").setTxPower(RSSI + 1).setRssi(RSSI).setScanType(
+                ScanRequest.SCAN_TYPE_NEARBY_PRESENCE).setAction(ACTION).setEncryptionKeyTag(
+                METADATA_ENCRYPTION_KEY_TAG).build();
+        runOperation(r.onNearbyDeviceDiscovered(device));
+
+        verify(mCallback, never()).onDiscovered(any());
+        verify(mCallback, never()).onUpdated(any());
+        verify(mCallback, never()).onLost(any());
+        verify(mCallback, times(1)).onError(eq(ScanCallback.ERROR_PERMISSION_DENIED));
+    }
+
+    private void runOperation(BinderListenerRegistration.ListenerOperation<IScanListener> operation)
+            throws Exception {
+        if (operation == null) {
+            return;
+        }
+        operation.onScheduled(false);
+        operation.operate(mCallback);
+        operation.onComplete(/* success= */ true);
+    }
+
+    private static class TestDiscoveryManager extends
+            ListenerMultiplexer<IScanListener, DiscoveryRegistration, MergedDiscoveryRequest> {
+
+        @Override
+        public MergedDiscoveryRequest mergeRegistrations(
+                @NonNull Collection<DiscoveryRegistration> discoveryRegistrations) {
+            return null;
+        }
+
+        @Override
+        public void onMergedRegistrationsUpdated() {
+
+        }
+    }
+}
diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index 383ed2c..a62ee7f 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -61,6 +61,7 @@
 import com.android.internal.util.State;
 import com.android.internal.util.StateMachine;
 import com.android.net.module.util.DeviceConfigUtils;
+import com.android.net.module.util.InetAddressUtils;
 import com.android.net.module.util.PermissionUtils;
 import com.android.net.module.util.SharedLog;
 import com.android.server.connectivity.mdns.ExecutorProvider;
@@ -1240,16 +1241,10 @@
         }
         for (String ipv6Address : v6Addrs) {
             try {
-                final InetAddress addr = InetAddresses.parseNumericAddress(ipv6Address);
-                if (addr.isLinkLocalAddress()) {
-                    final Inet6Address v6Addr = Inet6Address.getByAddress(
-                            null /* host */, addr.getAddress(),
-                            serviceInfo.getInterfaceIndex());
-                    addresses.add(v6Addr);
-                } else {
-                    addresses.add(addr);
-                }
-            } catch (IllegalArgumentException | UnknownHostException e) {
+                final Inet6Address addr = (Inet6Address) InetAddresses.parseNumericAddress(
+                        ipv6Address);
+                addresses.add(InetAddressUtils.withScopeId(addr, serviceInfo.getInterfaceIndex()));
+            } catch (IllegalArgumentException e) {
                 Log.wtf(TAG, "Invalid ipv6 address", e);
             }
         }
diff --git a/service-t/src/com/android/server/connectivity/mdns/ISocketNetLinkMonitor.java b/service-t/src/com/android/server/connectivity/mdns/AbstractSocketNetlink.java
similarity index 95%
rename from service-t/src/com/android/server/connectivity/mdns/ISocketNetLinkMonitor.java
rename to service-t/src/com/android/server/connectivity/mdns/AbstractSocketNetlink.java
index ef3928c..b792e46 100644
--- a/service-t/src/com/android/server/connectivity/mdns/ISocketNetLinkMonitor.java
+++ b/service-t/src/com/android/server/connectivity/mdns/AbstractSocketNetlink.java
@@ -19,7 +19,7 @@
 /**
  * The interface for netlink monitor.
  */
-public interface ISocketNetLinkMonitor {
+public interface AbstractSocketNetlink {
 
     /**
      * Returns if the netlink monitor is supported or not. By default, it is not supported.
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java b/service-t/src/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
index 31627f8..119c7a8 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsInterfaceSocket.java
@@ -78,7 +78,7 @@
         }
 
         mPacketReader = new MulticastPacketReader(networkInterface.getName(), mFileDescriptor,
-                new Handler(looper), packetReadBuffer, port);
+                new Handler(looper), packetReadBuffer);
         mPacketReader.start();
     }
 
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceCache.java b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceCache.java
new file mode 100644
index 0000000..bfda535
--- /dev/null
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceCache.java
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.server.connectivity.mdns.MdnsSocketProvider.ensureRunningOnHandlerThread;
+import static com.android.server.connectivity.mdns.util.MdnsUtils.equalsIgnoreDnsCase;
+import static com.android.server.connectivity.mdns.util.MdnsUtils.toDnsLowerCase;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.Network;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.ArrayMap;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * The {@link MdnsServiceCache} manages the service which discovers from each socket and cache these
+ * services to reduce duplicated queries.
+ *
+ * <p>This class is not thread safe, it is intended to be used only from the looper thread.
+ *  However, the constructor is an exception, as it is called on another thread;
+ *  therefore for thread safety all members of this class MUST either be final or initialized
+ *  to their default value (0, false or null).
+ */
+public class MdnsServiceCache {
+    private static class CacheKey {
+        @NonNull final String mLowercaseServiceType;
+        @Nullable final Network mNetwork;
+
+        CacheKey(@NonNull String serviceType, @Nullable Network network) {
+            mLowercaseServiceType = toDnsLowerCase(serviceType);
+            mNetwork = network;
+        }
+
+        @Override public int hashCode() {
+            return Objects.hash(mLowercaseServiceType, mNetwork);
+        }
+
+        @Override public boolean equals(Object other) {
+            if (this == other) {
+                return true;
+            }
+            if (!(other instanceof CacheKey)) {
+                return false;
+            }
+            return Objects.equals(mLowercaseServiceType, ((CacheKey) other).mLowercaseServiceType)
+                    && Objects.equals(mNetwork, ((CacheKey) other).mNetwork);
+        }
+    }
+    /**
+     * A map of cached services. Key is composed of service name, type and network. Value is the
+     * service which use the service type to discover from each socket.
+     */
+    @NonNull
+    private final ArrayMap<CacheKey, List<MdnsResponse>> mCachedServices = new ArrayMap<>();
+    @NonNull
+    private final Handler mHandler;
+
+    public MdnsServiceCache(@NonNull Looper looper) {
+        mHandler = new Handler(looper);
+    }
+
+    /**
+     * Get the cache services which are queried from given service type and network.
+     *
+     * @param serviceType the target service type.
+     * @param network the target network
+     * @return the set of services which matches the given service type.
+     */
+    @NonNull
+    public List<MdnsResponse> getCachedServices(@NonNull String serviceType,
+            @Nullable Network network) {
+        ensureRunningOnHandlerThread(mHandler);
+        final CacheKey key = new CacheKey(serviceType, network);
+        return mCachedServices.containsKey(key)
+                ? Collections.unmodifiableList(new ArrayList<>(mCachedServices.get(key)))
+                : Collections.emptyList();
+    }
+
+    private MdnsResponse findMatchedResponse(@NonNull List<MdnsResponse> responses,
+            @NonNull String serviceName) {
+        for (MdnsResponse response : responses) {
+            if (equalsIgnoreDnsCase(serviceName, response.getServiceInstanceName())) {
+                return response;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Get the cache service.
+     *
+     * @param serviceName the target service name.
+     * @param serviceType the target service type.
+     * @param network the target network
+     * @return the service which matches given conditions.
+     */
+    @Nullable
+    public MdnsResponse getCachedService(@NonNull String serviceName,
+            @NonNull String serviceType, @Nullable Network network) {
+        ensureRunningOnHandlerThread(mHandler);
+        final List<MdnsResponse> responses =
+                mCachedServices.get(new CacheKey(serviceType, network));
+        if (responses == null) {
+            return null;
+        }
+        final MdnsResponse response = findMatchedResponse(responses, serviceName);
+        return response != null ? new MdnsResponse(response) : null;
+    }
+
+    /**
+     * Add or update a service.
+     *
+     * @param serviceType the service type.
+     * @param network the target network
+     * @param response the response of the discovered service.
+     */
+    public void addOrUpdateService(@NonNull String serviceType, @Nullable Network network,
+            @NonNull MdnsResponse response) {
+        ensureRunningOnHandlerThread(mHandler);
+        final List<MdnsResponse> responses = mCachedServices.computeIfAbsent(
+                new CacheKey(serviceType, network), key -> new ArrayList<>());
+        // Remove existing service if present.
+        final MdnsResponse existing =
+                findMatchedResponse(responses, response.getServiceInstanceName());
+        responses.remove(existing);
+        responses.add(response);
+    }
+
+    /**
+     * Remove a service which matches the given service name, type and network.
+     *
+     * @param serviceName the target service name.
+     * @param serviceType the target service type.
+     * @param network the target network.
+     */
+    @Nullable
+    public MdnsResponse removeService(@NonNull String serviceName, @NonNull String serviceType,
+            @Nullable Network network) {
+        ensureRunningOnHandlerThread(mHandler);
+        final List<MdnsResponse> responses =
+                mCachedServices.get(new CacheKey(serviceType, network));
+        if (responses == null) {
+            return null;
+        }
+        final Iterator<MdnsResponse> iterator = responses.iterator();
+        while (iterator.hasNext()) {
+            final MdnsResponse response = iterator.next();
+            if (equalsIgnoreDnsCase(serviceName, response.getServiceInstanceName())) {
+                iterator.remove();
+                return response;
+            }
+        }
+        return null;
+    }
+
+    // TODO: check ttl expiration for each service and notify to the clients.
+}
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
index c45345a..b45a831 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
@@ -74,7 +74,7 @@
     @NonNull private final Dependencies mDependencies;
     @NonNull private final NetworkCallback mNetworkCallback;
     @NonNull private final TetheringEventCallback mTetheringEventCallback;
-    @NonNull private final ISocketNetLinkMonitor mSocketNetlinkMonitor;
+    @NonNull private final AbstractSocketNetlink mSocketNetlinkMonitor;
     private final ArrayMap<Network, SocketInfo> mNetworkSockets = new ArrayMap<>();
     private final ArrayMap<String, SocketInfo> mTetherInterfaceSockets = new ArrayMap<>();
     private final ArrayMap<Network, LinkProperties> mActiveNetworksLinkProperties =
@@ -171,7 +171,7 @@
             return iface.getIndex();
         }
         /*** Creates a SocketNetlinkMonitor */
-        public ISocketNetLinkMonitor createSocketNetlinkMonitor(@NonNull final Handler handler,
+        public AbstractSocketNetlink createSocketNetlinkMonitor(@NonNull final Handler handler,
                 @NonNull final SharedLog log,
                 @NonNull final NetLinkMonitorCallBack cb) {
             return SocketNetLinkMonitorFactory.createNetLinkMonitor(handler, log, cb);
diff --git a/service-t/src/com/android/server/connectivity/mdns/MulticastPacketReader.java b/service-t/src/com/android/server/connectivity/mdns/MulticastPacketReader.java
index 078c4dd..0e5a2a4 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MulticastPacketReader.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MulticastPacketReader.java
@@ -63,8 +63,10 @@
      */
     protected MulticastPacketReader(@NonNull String interfaceTag,
             @NonNull ParcelFileDescriptor socket, @NonNull Handler handler,
-            @NonNull byte[] buffer, int port) {
-        super(handler, new RecvBuffer(buffer, new InetSocketAddress(port)));
+            @NonNull byte[] buffer) {
+        // Set the port to zero as placeholder as the recvfrom() call will fill the actual port
+        // value later.
+        super(handler, new RecvBuffer(buffer, new InetSocketAddress(0 /* port */)));
         mLogTag = MulticastPacketReader.class.getSimpleName() + "/" + interfaceTag;
         mSocket = socket;
         mHandler = handler;
diff --git a/service-t/src/com/android/server/connectivity/mdns/SocketNetLinkMonitorFactory.java b/service-t/src/com/android/server/connectivity/mdns/SocketNetLinkMonitorFactory.java
index 4650255..6bc7941 100644
--- a/service-t/src/com/android/server/connectivity/mdns/SocketNetLinkMonitorFactory.java
+++ b/service-t/src/com/android/server/connectivity/mdns/SocketNetLinkMonitorFactory.java
@@ -30,7 +30,7 @@
     /**
      * Creates a new netlink monitor.
      */
-    public static ISocketNetLinkMonitor createNetLinkMonitor(@NonNull final Handler handler,
+    public static AbstractSocketNetlink createNetLinkMonitor(@NonNull final Handler handler,
             @NonNull SharedLog log, @NonNull MdnsSocketProvider.NetLinkMonitorCallBack cb) {
         return new SocketNetlinkMonitor(handler, log, cb);
     }
diff --git a/service-t/src/com/android/server/connectivity/mdns/internal/SocketNetlinkMonitor.java b/service-t/src/com/android/server/connectivity/mdns/internal/SocketNetlinkMonitor.java
index 6395b53..40191cf 100644
--- a/service-t/src/com/android/server/connectivity/mdns/internal/SocketNetlinkMonitor.java
+++ b/service-t/src/com/android/server/connectivity/mdns/internal/SocketNetlinkMonitor.java
@@ -28,13 +28,13 @@
 import com.android.net.module.util.netlink.NetlinkMessage;
 import com.android.net.module.util.netlink.RtNetlinkAddressMessage;
 import com.android.net.module.util.netlink.StructIfaddrMsg;
-import com.android.server.connectivity.mdns.ISocketNetLinkMonitor;
+import com.android.server.connectivity.mdns.AbstractSocketNetlink;
 import com.android.server.connectivity.mdns.MdnsSocketProvider;
 
 /**
  * The netlink monitor for MdnsSocketProvider.
  */
-public class SocketNetlinkMonitor extends NetlinkMonitor implements ISocketNetLinkMonitor {
+public class SocketNetlinkMonitor extends NetlinkMonitor implements AbstractSocketNetlink {
 
     public static final String TAG = SocketNetlinkMonitor.class.getSimpleName();
 
diff --git a/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java b/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java
new file mode 100644
index 0000000..4b0f2a4
--- /dev/null
+++ b/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns.util;
+
+import android.annotation.NonNull;
+
+/**
+ * Mdns utility functions.
+ */
+public class MdnsUtils {
+
+    private MdnsUtils() { }
+
+    /**
+     * Convert the string to DNS case-insensitive lowercase
+     *
+     * Per rfc6762#page-46, accented characters are not defined to be automatically equivalent to
+     * their unaccented counterparts. So the "DNS lowercase" should be if character is A-Z then they
+     * transform into a-z. Otherwise, they are kept as-is.
+     */
+    public static String toDnsLowerCase(@NonNull String string) {
+        final char[] outChars = new char[string.length()];
+        for (int i = 0; i < string.length(); i++) {
+            outChars[i] = toDnsLowerCase(string.charAt(i));
+        }
+        return new String(outChars);
+    }
+
+    /**
+     * Compare two strings by DNS case-insensitive lowercase.
+     */
+    public static boolean equalsIgnoreDnsCase(@NonNull String a, @NonNull String b) {
+        if (a.length() != b.length()) return false;
+        for (int i = 0; i < a.length(); i++) {
+            if (toDnsLowerCase(a.charAt(i)) != toDnsLowerCase(b.charAt(i))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static char toDnsLowerCase(char a) {
+        return a >= 'A' && a <= 'Z' ? (char) (a + ('a' - 'A')) : a;
+    }
+}
diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index 961337d..c660792 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -946,7 +946,11 @@
     @GuardedBy("mStatsLock")
     private void shutdownLocked() {
         final TetheringManager tetheringManager = mContext.getSystemService(TetheringManager.class);
-        tetheringManager.unregisterTetheringEventCallback(mTetherListener);
+        try {
+            tetheringManager.unregisterTetheringEventCallback(mTetherListener);
+        } catch (IllegalStateException e) {
+            Log.i(TAG, "shutdownLocked: error when unregister tethering, ignored. e=" + e);
+        }
         mContext.unregisterReceiver(mPollReceiver);
         mContext.unregisterReceiver(mRemovedReceiver);
         mContext.unregisterReceiver(mUserReceiver);
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index ba503e0..6fa2746 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -7904,16 +7904,27 @@
         return captivePortalBuilder.build();
     }
 
-    private String makeNflogPrefix(String iface, long networkHandle) {
+    @VisibleForTesting
+    static String makeNflogPrefix(String iface, long networkHandle) {
         // This needs to be kept in sync and backwards compatible with the decoding logic in
         // NetdEventListenerService, which is non-mainline code.
         return SdkLevel.isAtLeastU() ? (networkHandle + ":" + iface) : ("iface:" + iface);
     }
 
+    private static boolean isWakeupMarkingSupported(NetworkCapabilities capabilities) {
+        if (capabilities.hasTransport(TRANSPORT_WIFI)) {
+            return true;
+        }
+        if (SdkLevel.isAtLeastU() && capabilities.hasTransport(TRANSPORT_CELLULAR)) {
+            return true;
+        }
+        return false;
+    }
+
     private void wakeupModifyInterface(String iface, NetworkAgentInfo nai, boolean add) {
         // Marks are only available on WiFi interfaces. Checking for
         // marks on unsupported interfaces is harmless.
-        if (!nai.networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
+        if (!isWakeupMarkingSupported(nai.networkCapabilities)) {
             return;
         }
 
diff --git a/service/src/com/android/server/connectivity/NetworkDiagnostics.java b/service/src/com/android/server/connectivity/NetworkDiagnostics.java
index 509110d..15d0925 100644
--- a/service/src/com/android/server/connectivity/NetworkDiagnostics.java
+++ b/service/src/com/android/server/connectivity/NetworkDiagnostics.java
@@ -18,6 +18,11 @@
 
 import static android.system.OsConstants.*;
 
+import static com.android.net.module.util.NetworkStackConstants.ICMP_HEADER_LEN;
+import static com.android.net.module.util.NetworkStackConstants.IPV4_HEADER_MIN_LEN;
+import static com.android.net.module.util.NetworkStackConstants.IPV6_HEADER_LEN;
+import static com.android.net.module.util.NetworkStackConstants.IPV6_MIN_MTU;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.net.InetAddresses;
@@ -33,6 +38,7 @@
 import android.system.Os;
 import android.system.StructTimeval;
 import android.text.TextUtils;
+import android.util.Log;
 import android.util.Pair;
 
 import com.android.internal.util.IndentingPrintWriter;
@@ -172,7 +178,7 @@
         }
     }
 
-    private final Map<InetAddress, Measurement> mIcmpChecks = new HashMap<>();
+    private final Map<Pair<InetAddress, Integer>, Measurement> mIcmpChecks = new HashMap<>();
     private final Map<Pair<InetAddress, InetAddress>, Measurement> mExplicitSourceIcmpChecks =
             new HashMap<>();
     private final Map<InetAddress, Measurement> mDnsUdpChecks = new HashMap<>();
@@ -205,17 +211,21 @@
             mLinkProperties.addDnsServer(TEST_DNS6);
         }
 
+        final int mtu = mLinkProperties.getMtu();
         for (RouteInfo route : mLinkProperties.getRoutes()) {
             if (route.getType() == RouteInfo.RTN_UNICAST && route.hasGateway()) {
                 InetAddress gateway = route.getGateway();
-                prepareIcmpMeasurement(gateway);
+                // Use mtu in the route if exists. Otherwise, use the one in the link property.
+                final int routeMtu = route.getMtu();
+                prepareIcmpMeasurements(gateway, (routeMtu > 0) ? routeMtu : mtu);
                 if (route.isIPv6Default()) {
                     prepareExplicitSourceIcmpMeasurements(gateway);
                 }
             }
         }
+
         for (InetAddress nameserver : mLinkProperties.getDnsServers()) {
-            prepareIcmpMeasurement(nameserver);
+            prepareIcmpMeasurements(nameserver, mtu);
             prepareDnsMeasurement(nameserver);
 
             // Unlike the DnsResolver which doesn't do certificate validation in opportunistic mode,
@@ -261,11 +271,50 @@
                 localAddr.getHostAddress(), inetSockAddr.getPort());
     }
 
-    private void prepareIcmpMeasurement(InetAddress target) {
-        if (!mIcmpChecks.containsKey(target)) {
-            Measurement measurement = new Measurement();
-            measurement.thread = new Thread(new IcmpCheck(target, measurement));
-            mIcmpChecks.put(target, measurement);
+    private static int getHeaderLen(@NonNull InetAddress target) {
+        // Convert IPv4 mapped v6 address to v4 if any.
+        try {
+            final InetAddress addr = InetAddress.getByAddress(target.getAddress());
+            // An ICMPv6 header is technically 4 bytes, but the implementation in IcmpCheck#run()
+            // will always fill in another 4 bytes padding in the v6 diagnostic packets, so the size
+            // before icmp data is always 8 bytes in the implementation of ICMP diagnostics for both
+            // v4 and v6 packets. Thus, it's fine to use the v4 header size in the length
+            // calculation.
+            if (addr instanceof Inet6Address) {
+                return IPV6_HEADER_LEN + ICMP_HEADER_LEN;
+            }
+        } catch (UnknownHostException e) {
+            Log.e(TAG, "Create InetAddress fail(" + target + "): " + e);
+        }
+
+        return IPV4_HEADER_MIN_LEN + ICMP_HEADER_LEN;
+    }
+
+    private void prepareIcmpMeasurements(@NonNull InetAddress target, int targetNetworkMtu) {
+        // Test with different size payload ICMP.
+        // 1. Test with 0 payload.
+        addPayloadIcmpMeasurement(target, 0);
+        final int header = getHeaderLen(target);
+        // 2. Test with full size MTU.
+        addPayloadIcmpMeasurement(target, targetNetworkMtu - header);
+        // 3. If v6, make another measurement with the full v6 min MTU, unless that's what
+        //    was done above.
+        if ((target instanceof Inet6Address) && (targetNetworkMtu != IPV6_MIN_MTU)) {
+            addPayloadIcmpMeasurement(target, IPV6_MIN_MTU - header);
+        }
+    }
+
+    private void addPayloadIcmpMeasurement(@NonNull InetAddress target, int payloadLen) {
+        // This can happen if the there is no mtu filled(which is 0) in the link property.
+        // The value becomes negative after minus header length.
+        if (payloadLen < 0) return;
+
+        final Pair<InetAddress, Integer> lenTarget =
+                new Pair<>(target, Integer.valueOf(payloadLen));
+        if (!mIcmpChecks.containsKey(lenTarget)) {
+            final Measurement measurement = new Measurement();
+            measurement.thread = new Thread(new IcmpCheck(target, payloadLen, measurement));
+            mIcmpChecks.put(lenTarget, measurement);
         }
     }
 
@@ -276,7 +325,7 @@
                 Pair<InetAddress, InetAddress> srcTarget = new Pair<>(source, target);
                 if (!mExplicitSourceIcmpChecks.containsKey(srcTarget)) {
                     Measurement measurement = new Measurement();
-                    measurement.thread = new Thread(new IcmpCheck(source, target, measurement));
+                    measurement.thread = new Thread(new IcmpCheck(source, target, 0, measurement));
                     mExplicitSourceIcmpChecks.put(srcTarget, measurement);
                 }
             }
@@ -334,8 +383,8 @@
         ArrayList<Measurement> measurements = new ArrayList(totalMeasurementCount());
 
         // Sort measurements IPv4 first.
-        for (Map.Entry<InetAddress, Measurement> entry : mIcmpChecks.entrySet()) {
-            if (entry.getKey() instanceof Inet4Address) {
+        for (Map.Entry<Pair<InetAddress, Integer>, Measurement> entry : mIcmpChecks.entrySet()) {
+            if (entry.getKey().first instanceof Inet4Address) {
                 measurements.add(entry.getValue());
             }
         }
@@ -357,8 +406,8 @@
         }
 
         // IPv6 measurements second.
-        for (Map.Entry<InetAddress, Measurement> entry : mIcmpChecks.entrySet()) {
-            if (entry.getKey() instanceof Inet6Address) {
+        for (Map.Entry<Pair<InetAddress, Integer>, Measurement> entry : mIcmpChecks.entrySet()) {
+            if (entry.getKey().first instanceof Inet6Address) {
                 measurements.add(entry.getValue());
             }
         }
@@ -489,8 +538,11 @@
         private static final int PACKET_BUFSIZE = 512;
         private final int mProtocol;
         private final int mIcmpType;
+        private final int mPayloadSize;
+        // The length parameter is effectively the -s flag to ping/ping6 to specify the number of
+        // data bytes to be sent.
+        IcmpCheck(InetAddress source, InetAddress target, int length, Measurement measurement) {
 
-        public IcmpCheck(InetAddress source, InetAddress target, Measurement measurement) {
             super(source, target, measurement);
 
             if (mAddressFamily == AF_INET6) {
@@ -502,12 +554,13 @@
                 mIcmpType = NetworkConstants.ICMPV4_ECHO_REQUEST_TYPE;
                 mMeasurement.description = "ICMPv4";
             }
-
-            mMeasurement.description += " dst{" + mTarget.getHostAddress() + "}";
+            mPayloadSize = length;
+            mMeasurement.description += " payloadLength{" + mPayloadSize  + "}"
+                    + " dst{" + mTarget.getHostAddress() + "}";
         }
 
-        public IcmpCheck(InetAddress target, Measurement measurement) {
-            this(null, target, measurement);
+        IcmpCheck(InetAddress target, int length, Measurement measurement) {
+            this(null, target, length, measurement);
         }
 
         @Override
@@ -523,9 +576,11 @@
             mMeasurement.description += " src{" + socketAddressToString(mSocketAddress) + "}";
 
             // Build a trivial ICMP packet.
-            final byte[] icmpPacket = {
-                    (byte) mIcmpType, 0, 0, 0, 0, 0, 0, 0  // ICMP header
-            };
+            // The v4 ICMP header ICMP_HEADER_LEN (which is 8) and v6 is only 4 bytes (4 bytes
+            // message body followed by header before the payload).
+            // Use 8 bytes for both v4 and v6 for simplicity.
+            final byte[] icmpPacket = new byte[ICMP_HEADER_LEN + mPayloadSize];
+            icmpPacket[0] = (byte) mIcmpType;
 
             int count = 0;
             mMeasurement.startTime = now();
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 3188c9c..32c854b 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -154,6 +154,7 @@
 import static com.android.server.ConnectivityService.PREFERENCE_ORDER_PROFILE;
 import static com.android.server.ConnectivityService.PREFERENCE_ORDER_VPN;
 import static com.android.server.ConnectivityService.createDeliveryGroupKeyForConnectivityAction;
+import static com.android.server.ConnectivityService.makeNflogPrefix;
 import static com.android.server.ConnectivityServiceTestUtils.transportToLegacyType;
 import static com.android.server.NetworkAgentWrapper.CallbackType.OnQosCallbackRegister;
 import static com.android.server.NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister;
@@ -533,6 +534,10 @@
     private static final int TEST_PACKAGE_UID = 123;
     private static final int TEST_PACKAGE_UID2 = 321;
     private static final int TEST_PACKAGE_UID3 = 456;
+
+    private static final int PACKET_WAKEUP_MASK = 0xffff0000;
+    private static final int PACKET_WAKEUP_MARK = 0x88880000;
+
     private static final String ALWAYS_ON_PACKAGE = "com.android.test.alwaysonvpn";
 
     private static final String INTERFACE_NAME = "interface";
@@ -1910,6 +1915,10 @@
         doReturn(0).when(mResources).getInteger(R.integer.config_activelyPreferBadWifi);
         doReturn(true).when(mResources)
                 .getBoolean(R.bool.config_cellular_radio_timesharing_capable);
+        doReturn(PACKET_WAKEUP_MASK).when(mResources).getInteger(
+                R.integer.config_networkWakeupPacketMask);
+        doReturn(PACKET_WAKEUP_MARK).when(mResources).getInteger(
+                R.integer.config_networkWakeupPacketMark);
     }
 
     class ConnectivityServiceDependencies extends ConnectivityService.Dependencies {
@@ -10386,6 +10395,16 @@
         return event;
     }
 
+    private void verifyWakeupModifyInterface(String iface, boolean add) throws RemoteException {
+        if (add) {
+            verify(mMockNetd).wakeupAddInterface(eq(iface), anyString(), anyInt(),
+                    anyInt());
+        } else {
+            verify(mMockNetd).wakeupDelInterface(eq(iface), anyString(), anyInt(),
+                    anyInt());
+        }
+    }
+
     private <T> T verifyWithOrder(@Nullable InOrder inOrder, @NonNull T t) {
         if (inOrder != null) {
             return inOrder.verify(t);
@@ -10612,6 +10631,11 @@
         clat.interfaceRemoved(CLAT_MOBILE_IFNAME);
         networkCallback.assertNoCallback();
         verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_MOBILE_IFNAME);
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(CLAT_MOBILE_IFNAME, false);
+        }
+
         verifyNoMoreInteractions(mMockNetd);
         verifyNoMoreInteractions(mClatCoordinator);
         verifyNoMoreInteractions(mMockDnsResolver);
@@ -10648,6 +10672,10 @@
         assertRoutesAdded(cellNetId, stackedDefault);
         verify(mMockNetd, times(1)).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
 
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(CLAT_MOBILE_IFNAME, true);
+        }
+
         // NAT64 prefix is removed. Expect that clat is stopped.
         mService.mResolverUnsolEventCallback.onNat64PrefixEvent(makeNat64PrefixEvent(
                 cellNetId, PREFIX_OPERATION_REMOVED, kNat64PrefixString, 96));
@@ -10662,6 +10690,11 @@
                 cb -> cb.getLp().getStackedLinks().size() == 0);
         verify(mMockNetd, times(1)).networkRemoveInterface(cellNetId, CLAT_MOBILE_IFNAME);
         verify(mMockNetd, times(1)).interfaceGetCfg(CLAT_MOBILE_IFNAME);
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(CLAT_MOBILE_IFNAME, false);
+        }
+
         // Clean up.
         mCellAgent.disconnect();
         networkCallback.expect(LOST, mCellAgent);
@@ -10674,6 +10707,11 @@
         } else {
             verify(mMockNetd, never()).setNetworkAllowlist(any());
         }
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(MOBILE_IFNAME, false);
+        }
+
         verifyNoMoreInteractions(mMockNetd);
         verifyNoMoreInteractions(mClatCoordinator);
         reset(mMockNetd);
@@ -10703,6 +10741,11 @@
         verify(mMockNetd).networkAddInterface(cellNetId, CLAT_MOBILE_IFNAME);
         // assertRoutesAdded sees all calls since last mMockNetd reset, so expect IPv6 routes again.
         assertRoutesAdded(cellNetId, ipv6Subnet, ipv6Default, stackedDefault);
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(MOBILE_IFNAME, true);
+        }
+
         reset(mMockNetd);
         reset(mClatCoordinator);
 
@@ -10711,6 +10754,11 @@
         networkCallback.expect(LOST, mCellAgent);
         networkCallback.assertNoCallback();
         verifyClatdStop(null /* inOrder */, MOBILE_IFNAME);
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(CLAT_MOBILE_IFNAME, false);
+        }
+
         verify(mMockNetd).idletimerRemoveInterface(eq(MOBILE_IFNAME), anyInt(),
                 eq(Integer.toString(TRANSPORT_CELLULAR)));
         verify(mMockNetd).networkDestroy(cellNetId);
@@ -10719,6 +10767,11 @@
         } else {
             verify(mMockNetd, never()).setNetworkAllowlist(any());
         }
+
+        if (SdkLevel.isAtLeastU()) {
+            verifyWakeupModifyInterface(MOBILE_IFNAME, false);
+        }
+
         verifyNoMoreInteractions(mMockNetd);
         verifyNoMoreInteractions(mClatCoordinator);
 
@@ -17666,4 +17719,48 @@
         info.setExtraInfo("test_info");
         assertEquals("0;2;test_info", createDeliveryGroupKeyForConnectivityAction(info));
     }
+
+    @Test
+    public void testNetdWakeupAddInterfaceForWifiTransport() throws Exception {
+        final LinkProperties wifiLp = new LinkProperties();
+        wifiLp.setInterfaceName(WIFI_IFNAME);
+        mWiFiAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI, wifiLp);
+        mWiFiAgent.connect(false /* validated */);
+
+        final String expectedPrefix = makeNflogPrefix(WIFI_IFNAME,
+                mWiFiAgent.getNetwork().getNetworkHandle());
+        verify(mMockNetd).wakeupAddInterface(WIFI_IFNAME, expectedPrefix, PACKET_WAKEUP_MARK,
+                PACKET_WAKEUP_MASK);
+    }
+
+    @Test
+    public void testNetdWakeupAddInterfaceForCellularTransport() throws Exception {
+        final LinkProperties cellLp = new LinkProperties();
+        cellLp.setInterfaceName(MOBILE_IFNAME);
+        mCellAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR, cellLp);
+        mCellAgent.connect(false /* validated */);
+
+        if (SdkLevel.isAtLeastU()) {
+            final String expectedPrefix = makeNflogPrefix(MOBILE_IFNAME,
+                    mCellAgent.getNetwork().getNetworkHandle());
+            verify(mMockNetd).wakeupAddInterface(MOBILE_IFNAME, expectedPrefix, PACKET_WAKEUP_MARK,
+                    PACKET_WAKEUP_MASK);
+        } else {
+            verify(mMockNetd, never()).wakeupAddInterface(eq(MOBILE_IFNAME), anyString(), anyInt(),
+                    anyInt());
+        }
+    }
+
+    @Test
+    public void testNetdWakeupAddInterfaceForEthernetTransport() throws Exception {
+        final String ethernetIface = "eth42";
+
+        final LinkProperties ethLp = new LinkProperties();
+        ethLp.setInterfaceName(ethernetIface);
+        mEthernetAgent = new TestNetworkAgentWrapper(TRANSPORT_ETHERNET, ethLp);
+        mEthernetAgent.connect(false /* validated */);
+
+        verify(mMockNetd, never()).wakeupAddInterface(eq(ethernetIface), anyString(), anyInt(),
+                anyInt());
+    }
 }
diff --git a/tests/unit/java/com/android/server/connectivity/NetdEventListenerServiceTest.java b/tests/unit/java/com/android/server/connectivity/NetdEventListenerServiceTest.java
index f4b6464..d667662 100644
--- a/tests/unit/java/com/android/server/connectivity/NetdEventListenerServiceTest.java
+++ b/tests/unit/java/com/android/server/connectivity/NetdEventListenerServiceTest.java
@@ -24,6 +24,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 
@@ -41,6 +42,8 @@
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
 
+import libcore.util.EmptyArray;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -60,7 +63,8 @@
     private static final String EXAMPLE_IPV4 = "192.0.2.1";
     private static final String EXAMPLE_IPV6 = "2001:db8:1200::2:1";
 
-    private static final long NET_HANDLE = new Network(5391).getNetworkHandle();
+    private static final Network TEST_WIFI_NETWORK = new Network(5391);
+    private static final Network TEST_CELL_NETWORK = new Network(5832);
 
     private static final byte[] MAC_ADDR =
             {(byte)0x84, (byte)0xc9, (byte)0xb2, (byte)0x6a, (byte)0xed, (byte)0x4b};
@@ -78,6 +82,8 @@
     public void setUp() {
         mCm = mock(ConnectivityManager.class);
         mService = new NetdEventListenerService(mCm);
+        doReturn(CAPABILITIES_WIFI).when(mCm).getNetworkCapabilities(TEST_WIFI_NETWORK);
+        doReturn(CAPABILITIES_CELL).when(mCm).getNetworkCapabilities(TEST_CELL_NETWORK);
     }
 
     @Test
@@ -111,19 +117,25 @@
         wakeupEvent(iface, uids[5], v4, tcp, mac, srcIp, dstIp, sport, dport, now);
         wakeupEvent(iface, uids[6], v6, udp, mac, srcIp6, dstIp6, sport, dport, now);
         wakeupEvent(iface, uids[7], v6, tcp, mac, srcIp6, dstIp6, sport, dport, now);
-        wakeupEvent(iface, uids[8], v6, udp, mac, srcIp6, dstIp6, sport, dport, now);
+        wakeupEvent("rmnet0", uids[8], v6, udp, EmptyArray.BYTE, srcIp6, dstIp6, sport, dport, now,
+                TEST_CELL_NETWORK);
 
         String[] events2 = remove(listNetdEvent(), baseline);
-        int expectedLength2 = uids.length + 1; // +1 for the WakeupStats line
+        int expectedLength2 = uids.length + 2; // +2 for the WakeupStats headers
         assertEquals(expectedLength2, events2.length);
+
         assertStringContains(events2[0], "WakeupStats");
-        assertStringContains(events2[0], "wlan0");
-        assertStringContains(events2[0], "0x800");
+        assertStringContains(events2[0], "rmnet0");
         assertStringContains(events2[0], "0x86dd");
+
+        assertStringContains(events2[1], "WakeupStats");
+        assertStringContains(events2[1], "wlan0");
+        assertStringContains(events2[1], "0x800");
+        assertStringContains(events2[1], "0x86dd");
         for (int i = 0; i < uids.length; i++) {
-            String got = events2[i+1];
+            String got = events2[i + 2];
             assertStringContains(got, "WakeupEvent");
-            assertStringContains(got, "wlan0");
+            assertStringContains(got, ((i == 8) ? "rmnet0" : "wlan0"));
             assertStringContains(got, "uid: " + uids[i]);
         }
 
@@ -134,11 +146,13 @@
         }
 
         String[] events3 = remove(listNetdEvent(), baseline);
-        int expectedLength3 = BUFFER_LENGTH + 1; // +1 for the WakeupStats line
+        int expectedLength3 = BUFFER_LENGTH + 2; // +2 for the WakeupStats headers
         assertEquals(expectedLength3, events3.length);
-        assertStringContains(events2[0], "WakeupStats");
-        assertStringContains(events2[0], "wlan0");
-        for (int i = 1; i < expectedLength3; i++) {
+        assertStringContains(events3[0], "WakeupStats");
+        assertStringContains(events3[0], "rmnet0");
+        assertStringContains(events3[1], "WakeupStats");
+        assertStringContains(events3[1], "wlan0");
+        for (int i = 2; i < expectedLength3; i++) {
             String got = events3[i];
             assertStringContains(got, "WakeupEvent");
             assertStringContains(got, "wlan0");
@@ -173,19 +187,24 @@
         final int icmp6 = 58;
 
         wakeupEvent("wlan0", 1000, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
-        wakeupEvent("rmnet0", 10123, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
+        wakeupEvent("rmnet0", 10123, v4, tcp, mac, srcIp, dstIp, sport, dport, now,
+                TEST_CELL_NETWORK);
         wakeupEvent("wlan0", 1000, v4, udp, mac, srcIp, dstIp, sport, dport, now);
-        wakeupEvent("rmnet0", 10008, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
+        wakeupEvent("rmnet0", 10008, v4, tcp, EmptyArray.BYTE, srcIp, dstIp, sport, dport, now,
+                TEST_CELL_NETWORK);
         wakeupEvent("wlan0", -1, v6, icmp6, mac, srcIp6, dstIp6, sport, dport, now);
         wakeupEvent("wlan0", 10008, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
-        wakeupEvent("rmnet0", 1000, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
+        wakeupEvent("rmnet0", 1000, v4, tcp, mac, srcIp, dstIp, sport, dport, now,
+                TEST_CELL_NETWORK);
         wakeupEvent("wlan0", 10004, v4, udp, mac, srcIp, dstIp, sport, dport, now);
         wakeupEvent("wlan0", 1000, v6, tcp, mac, srcIp6, dstIp6, sport, dport, now);
         wakeupEvent("wlan0", 0, v6, udp, mac, srcIp6, dstIp6, sport, dport, now);
         wakeupEvent("wlan0", -1, v6, icmp6, mac, srcIp6, dstIp6, sport, dport, now);
-        wakeupEvent("rmnet0", 10052, v4, tcp, mac, srcIp, dstIp, sport, dport, now);
+        wakeupEvent("rmnet0", 10052, v4, tcp, mac, srcIp, dstIp, sport, dport, now,
+                TEST_CELL_NETWORK);
         wakeupEvent("wlan0", 0, v6, udp, mac, srcIp6, dstIp6, sport, dport, now);
-        wakeupEvent("rmnet0", 1000, v6, tcp, mac, srcIp6, dstIp6, sport, dport, now);
+        wakeupEvent("rmnet0", 1000, v6, tcp, null, srcIp6, dstIp6, sport, dport, now,
+                TEST_CELL_NETWORK);
         wakeupEvent("wlan0", 1010, v4, udp, mac, srcIp, dstIp, sport, dport, now);
 
         String got = flushStatistics();
@@ -214,7 +233,7 @@
                 "    >",
                 "    l2_broadcast_count: 0",
                 "    l2_multicast_count: 0",
-                "    l2_unicast_count: 5",
+                "    l2_unicast_count: 3",
                 "    no_uid_wakeups: 0",
                 "    non_application_wakeups: 0",
                 "    root_wakeups: 0",
@@ -499,8 +518,13 @@
     }
 
     void wakeupEvent(String iface, int uid, int ether, int ip, byte[] mac, String srcIp,
-            String dstIp, int sport, int dport, long now) throws Exception {
-        String prefix = NET_HANDLE + ":" + iface;
+            String dstIp, int sport, int dport, long now) {
+        wakeupEvent(iface, uid, ether, ip, mac, srcIp, dstIp, sport, dport, now, TEST_WIFI_NETWORK);
+    }
+
+    void wakeupEvent(String iface, int uid, int ether, int ip, byte[] mac, String srcIp,
+            String dstIp, int sport, int dport, long now, Network network) {
+        String prefix = network.getNetworkHandle() + ":" + iface;
         mService.onWakeupEvent(prefix, uid, ether, ip, mac, srcIp, dstIp, sport, dport, now);
     }
 
diff --git a/tests/unit/java/com/android/server/connectivity/VpnTest.java b/tests/unit/java/com/android/server/connectivity/VpnTest.java
index 2926c9a..395e2bb 100644
--- a/tests/unit/java/com/android/server/connectivity/VpnTest.java
+++ b/tests/unit/java/com/android/server/connectivity/VpnTest.java
@@ -142,6 +142,7 @@
 import android.net.ipsec.ike.exceptions.IkeNonProtocolException;
 import android.net.ipsec.ike.exceptions.IkeProtocolException;
 import android.net.ipsec.ike.exceptions.IkeTimeoutException;
+import android.net.vcn.VcnTransportInfo;
 import android.net.wifi.WifiInfo;
 import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
@@ -1563,6 +1564,11 @@
     }
 
     private NetworkCallback triggerOnAvailableAndGetCallback() throws Exception {
+        return triggerOnAvailableAndGetCallback(new NetworkCapabilities.Builder().build());
+    }
+
+    private NetworkCallback triggerOnAvailableAndGetCallback(
+            @NonNull final NetworkCapabilities caps) throws Exception {
         final ArgumentCaptor<NetworkCallback> networkCallbackCaptor =
                 ArgumentCaptor.forClass(NetworkCallback.class);
         verify(mConnectivityManager, timeout(TEST_TIMEOUT_MS))
@@ -1579,7 +1585,7 @@
         // if NetworkCapabilities and LinkProperties of underlying network will be sent/cleared or
         // not.
         // See verifyVpnManagerEvent().
-        cb.onCapabilitiesChanged(TEST_NETWORK, new NetworkCapabilities());
+        cb.onCapabilitiesChanged(TEST_NETWORK, caps);
         cb.onLinkPropertiesChanged(TEST_NETWORK, new LinkProperties());
         return cb;
     }
@@ -1903,12 +1909,15 @@
 
     private PlatformVpnSnapshot verifySetupPlatformVpn(VpnProfile vpnProfile,
             IkeSessionConfiguration ikeConfig, boolean mtuSupportsIpv6) throws Exception {
-        return verifySetupPlatformVpn(vpnProfile, ikeConfig, mtuSupportsIpv6,
-                false /* areLongLivedTcpConnectionsExpensive */);
+        return verifySetupPlatformVpn(vpnProfile, ikeConfig,
+                new NetworkCapabilities.Builder().build() /* underlying network caps */,
+                mtuSupportsIpv6, false /* areLongLivedTcpConnectionsExpensive */);
     }
 
     private PlatformVpnSnapshot verifySetupPlatformVpn(VpnProfile vpnProfile,
-            IkeSessionConfiguration ikeConfig, boolean mtuSupportsIpv6,
+            IkeSessionConfiguration ikeConfig,
+            @NonNull final NetworkCapabilities underlyingNetworkCaps,
+            boolean mtuSupportsIpv6,
             boolean areLongLivedTcpConnectionsExpensive) throws Exception {
         if (!mtuSupportsIpv6) {
             doReturn(IPV6_MIN_MTU - 1).when(mTestDeps).calculateVpnMtu(any(), anyInt(), anyInt(),
@@ -1925,7 +1934,7 @@
                 .thenReturn(vpnProfile.encode());
 
         vpn.startVpnProfile(TEST_VPN_PKG);
-        final NetworkCallback nwCb = triggerOnAvailableAndGetCallback();
+        final NetworkCallback nwCb = triggerOnAvailableAndGetCallback(underlyingNetworkCaps);
         verify(mExecutor, atLeastOnce()).schedule(any(Runnable.class), anyLong(), any());
         reset(mExecutor);
 
@@ -2079,15 +2088,16 @@
         doTestMigrateIkeSession(ikeProfile.toVpnProfile(),
                 expectedKeepalive,
                 ESP_IP_VERSION_AUTO /* expectedIpVersion */,
-                ESP_ENCAP_TYPE_AUTO /* expectedEncapType */);
+                ESP_ENCAP_TYPE_AUTO /* expectedEncapType */,
+                new NetworkCapabilities.Builder().build());
     }
 
-    private void doTestMigrateIkeSession_FromIkeTunnConnParams(
+    private Ikev2VpnProfile makeIkeV2VpnProfile(
             boolean isAutomaticIpVersionSelectionEnabled,
             boolean isAutomaticNattKeepaliveTimerEnabled,
             int keepaliveInProfile,
             int ipVersionInProfile,
-            int encapTypeInProfile) throws Exception {
+            int encapTypeInProfile) {
         // TODO: Update helper function in IkeSessionTestUtils to support building IkeSessionParams
         // with IP version and encap type when mainline-prod branch support these two APIs.
         final IkeSessionParams params = getTestIkeSessionParams(true /* testIpv6 */,
@@ -2099,12 +2109,40 @@
 
         final IkeTunnelConnectionParams tunnelParams =
                 new IkeTunnelConnectionParams(ikeSessionParams, CHILD_PARAMS);
-        final Ikev2VpnProfile ikeProfile = new Ikev2VpnProfile.Builder(tunnelParams)
+        return new Ikev2VpnProfile.Builder(tunnelParams)
                 .setBypassable(true)
                 .setAutomaticNattKeepaliveTimerEnabled(isAutomaticNattKeepaliveTimerEnabled)
                 .setAutomaticIpVersionSelectionEnabled(isAutomaticIpVersionSelectionEnabled)
                 .build();
+    }
 
+    private void doTestMigrateIkeSession_FromIkeTunnConnParams(
+            boolean isAutomaticIpVersionSelectionEnabled,
+            boolean isAutomaticNattKeepaliveTimerEnabled,
+            int keepaliveInProfile,
+            int ipVersionInProfile,
+            int encapTypeInProfile) throws Exception {
+        doTestMigrateIkeSession_FromIkeTunnConnParams(isAutomaticIpVersionSelectionEnabled,
+                isAutomaticNattKeepaliveTimerEnabled, keepaliveInProfile, ipVersionInProfile,
+                encapTypeInProfile, new NetworkCapabilities.Builder().build());
+    }
+
+    private void doTestMigrateIkeSession_FromIkeTunnConnParams(
+            boolean isAutomaticIpVersionSelectionEnabled,
+            boolean isAutomaticNattKeepaliveTimerEnabled,
+            int keepaliveInProfile,
+            int ipVersionInProfile,
+            int encapTypeInProfile,
+            @NonNull final NetworkCapabilities nc) throws Exception {
+        final Ikev2VpnProfile ikeProfile = makeIkeV2VpnProfile(
+                isAutomaticIpVersionSelectionEnabled,
+                isAutomaticNattKeepaliveTimerEnabled,
+                keepaliveInProfile,
+                ipVersionInProfile,
+                encapTypeInProfile);
+
+        final IkeSessionParams ikeSessionParams =
+                ikeProfile.getIkeTunnelConnectionParams().getIkeSessionParams();
         final int expectedKeepalive = isAutomaticNattKeepaliveTimerEnabled
                 ? AUTOMATIC_KEEPALIVE_DELAY_SECONDS
                 : ikeSessionParams.getNattKeepAliveDelaySeconds();
@@ -2115,22 +2153,48 @@
                 ? ESP_ENCAP_TYPE_AUTO
                 : ikeSessionParams.getEncapType();
         doTestMigrateIkeSession(ikeProfile.toVpnProfile(), expectedKeepalive,
-                expectedIpVersion, expectedEncapType);
+                expectedIpVersion, expectedEncapType, nc);
     }
 
-    private void doTestMigrateIkeSession(VpnProfile profile,
-            int expectedKeepalive, int expectedIpVersion, int expectedEncapType) throws Exception {
+    @Test
+    public void doTestMigrateIkeSession_Vcn() throws Exception {
+        final int expectedKeepalive = 2097; // Any unlikely number will do
+        final NetworkCapabilities vcnNc = new NetworkCapabilities.Builder()
+                .addTransportType(TRANSPORT_CELLULAR)
+                .setTransportInfo(new VcnTransportInfo(TEST_SUB_ID, expectedKeepalive))
+                .build();
+        final Ikev2VpnProfile ikev2VpnProfile = makeIkeV2VpnProfile(
+                true /* isAutomaticIpVersionSelectionEnabled */,
+                true /* isAutomaticNattKeepaliveTimerEnabled */,
+                234 /* keepaliveInProfile */, // Should be ignored, any value will do
+                ESP_IP_VERSION_IPV4, // Should be ignored
+                ESP_ENCAP_TYPE_UDP // Should be ignored
+        );
+        doTestMigrateIkeSession(
+                ikev2VpnProfile.toVpnProfile(),
+                expectedKeepalive,
+                ESP_IP_VERSION_AUTO /* expectedIpVersion */,
+                ESP_ENCAP_TYPE_AUTO /* expectedEncapType */,
+                vcnNc);
+    }
+
+    private void doTestMigrateIkeSession(
+            @NonNull final VpnProfile profile,
+            final int expectedKeepalive,
+            final int expectedIpVersion,
+            final int expectedEncapType,
+            @NonNull final NetworkCapabilities caps) throws Exception {
         final PlatformVpnSnapshot vpnSnapShot =
                 verifySetupPlatformVpn(profile,
                         createIkeConfig(createIkeConnectInfo(), true /* isMobikeEnabled */),
+                        caps /* underlying network capabilities */,
                         false /* mtuSupportsIpv6 */,
                         expectedKeepalive < DEFAULT_LONG_LIVED_TCP_CONNS_EXPENSIVE_TIMEOUT_SEC);
         // Simulate a new network coming up
         vpnSnapShot.nwCb.onAvailable(TEST_NETWORK_2);
         verify(mIkeSessionWrapper, never()).setNetwork(any(), anyInt(), anyInt(), anyInt());
 
-        vpnSnapShot.nwCb.onCapabilitiesChanged(
-                TEST_NETWORK_2, new NetworkCapabilities.Builder().build());
+        vpnSnapShot.nwCb.onCapabilitiesChanged(TEST_NETWORK_2, caps);
         // Verify MOBIKE is triggered
         verify(mIkeSessionWrapper, timeout(TEST_TIMEOUT_MS)).setNetwork(TEST_NETWORK_2,
                 expectedIpVersion, expectedEncapType, expectedKeepalive);
@@ -2156,6 +2220,7 @@
         final PlatformVpnSnapshot vpnSnapShot =
                 verifySetupPlatformVpn(ikeProfile.toVpnProfile(),
                         createIkeConfig(createIkeConnectInfo(), true /* isMobikeEnabled */),
+                        new NetworkCapabilities.Builder().build() /* underlying network caps */,
                         hasV6 /* mtuSupportsIpv6 */,
                         false /* areLongLivedTcpConnectionsExpensive */);
         reset(mExecutor);
@@ -2343,6 +2408,7 @@
         final PlatformVpnSnapshot vpnSnapShot =
                 verifySetupPlatformVpn(ikeProfile.toVpnProfile(),
                         createIkeConfig(createIkeConnectInfo(), true /* isMobikeEnabled */),
+                        new NetworkCapabilities.Builder().build() /* underlying network caps */,
                         false /* mtuSupportsIpv6 */,
                         true /* areLongLivedTcpConnectionsExpensive */);
 
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceCacheTest.kt b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceCacheTest.kt
new file mode 100644
index 0000000..f091eea
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceCacheTest.kt
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License")
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns
+
+import android.net.Network
+import android.os.Build
+import android.os.Handler
+import android.os.HandlerThread
+import com.android.testutils.DevSdkIgnoreRule
+import com.android.testutils.DevSdkIgnoreRunner
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.TimeUnit
+import kotlin.test.assertNotNull
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+
+private const val SERVICE_NAME_1 = "service-instance-1"
+private const val SERVICE_NAME_2 = "service-instance-2"
+private const val SERVICE_TYPE_1 = "_test1._tcp.local"
+private const val SERVICE_TYPE_2 = "_test2._tcp.local"
+private const val INTERFACE_INDEX = 999
+private const val DEFAULT_TIMEOUT_MS = 2000L
+
+@RunWith(DevSdkIgnoreRunner::class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
+class MdnsServiceCacheTest {
+    private val network = mock(Network::class.java)
+    private val thread = HandlerThread(MdnsServiceCacheTest::class.simpleName)
+    private val handler by lazy {
+        Handler(thread.looper)
+    }
+    private val serviceCache by lazy {
+        MdnsServiceCache(thread.looper)
+    }
+
+    @Before
+    fun setUp() {
+        thread.start()
+    }
+
+    @After
+    fun tearDown() {
+        thread.quitSafely()
+    }
+
+    private fun <T> runningOnHandlerAndReturn(functor: (() -> T)): T {
+        val future = CompletableFuture<T>()
+        handler.post {
+            future.complete(functor())
+        }
+        return future.get(DEFAULT_TIMEOUT_MS, TimeUnit.MILLISECONDS)
+    }
+
+    private fun addOrUpdateService(serviceType: String, network: Network, service: MdnsResponse):
+            Unit = runningOnHandlerAndReturn {
+        serviceCache.addOrUpdateService(serviceType, network, service) }
+
+    private fun removeService(serviceName: String, serviceType: String, network: Network):
+            Unit = runningOnHandlerAndReturn {
+        serviceCache.removeService(serviceName, serviceType, network) }
+
+    private fun getService(serviceName: String, serviceType: String, network: Network):
+            MdnsResponse? = runningOnHandlerAndReturn {
+        serviceCache.getCachedService(serviceName, serviceType, network) }
+
+    private fun getServices(serviceType: String, network: Network): List<MdnsResponse> =
+        runningOnHandlerAndReturn { serviceCache.getCachedServices(serviceType, network) }
+
+    @Test
+    fun testAddAndRemoveService() {
+        addOrUpdateService(SERVICE_TYPE_1, network, createResponse(SERVICE_NAME_1, SERVICE_TYPE_1))
+        var response = getService(SERVICE_NAME_1, SERVICE_TYPE_1, network)
+        assertNotNull(response)
+        assertEquals(SERVICE_NAME_1, response.serviceInstanceName)
+        removeService(SERVICE_NAME_1, SERVICE_TYPE_1, network)
+        response = getService(SERVICE_NAME_1, SERVICE_TYPE_1, network)
+        assertNull(response)
+    }
+
+    @Test
+    fun testGetCachedServices_multipleServiceTypes() {
+        addOrUpdateService(SERVICE_TYPE_1, network, createResponse(SERVICE_NAME_1, SERVICE_TYPE_1))
+        addOrUpdateService(SERVICE_TYPE_1, network, createResponse(SERVICE_NAME_2, SERVICE_TYPE_1))
+        addOrUpdateService(SERVICE_TYPE_2, network, createResponse(SERVICE_NAME_2, SERVICE_TYPE_2))
+
+        val responses1 = getServices(SERVICE_TYPE_1, network)
+        assertEquals(2, responses1.size)
+        assertTrue(responses1.stream().anyMatch { response ->
+            response.serviceInstanceName == SERVICE_NAME_1
+        })
+        assertTrue(responses1.any { response ->
+            response.serviceInstanceName == SERVICE_NAME_2
+        })
+        val responses2 = getServices(SERVICE_TYPE_2, network)
+        assertEquals(1, responses2.size)
+        assertTrue(responses2.any { response ->
+            response.serviceInstanceName == SERVICE_NAME_2
+        })
+
+        removeService(SERVICE_NAME_2, SERVICE_TYPE_1, network)
+        val responses3 = getServices(SERVICE_TYPE_1, network)
+        assertEquals(1, responses3.size)
+        assertTrue(responses3.any { response ->
+            response.serviceInstanceName == SERVICE_NAME_1
+        })
+        val responses4 = getServices(SERVICE_TYPE_2, network)
+        assertEquals(1, responses4.size)
+        assertTrue(responses4.any { response ->
+            response.serviceInstanceName == SERVICE_NAME_2
+        })
+    }
+
+    private fun createResponse(serviceInstanceName: String, serviceType: String) = MdnsResponse(
+        0 /* now */, "$serviceInstanceName.$serviceType".split(".").toTypedArray(),
+            INTERFACE_INDEX, network)
+}
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
index 2d73c98..6f3322b 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
@@ -112,7 +112,7 @@
     private NetworkCallback mNetworkCallback;
     private TetheringEventCallback mTetheringEventCallback;
 
-    private TestNetLinkMonitor mTestSocketNetLinkMonitor;
+    private TestNetlinkMonitor mTestSocketNetLinkMonitor;
     @Before
     public void setUp() throws IOException {
         MockitoAnnotations.initMocks(this);
@@ -147,7 +147,7 @@
         doReturn(mTestSocketNetLinkMonitor).when(mDeps).createSocketNetlinkMonitor(any(), any(),
                 any());
         doAnswer(inv -> {
-            mTestSocketNetLinkMonitor = new TestNetLinkMonitor(inv.getArgument(0),
+            mTestSocketNetLinkMonitor = new TestNetlinkMonitor(inv.getArgument(0),
                     inv.getArgument(1),
                     inv.getArgument(2));
             return mTestSocketNetLinkMonitor;
@@ -174,8 +174,8 @@
         HandlerUtils.waitForIdle(mHandler, DEFAULT_TIMEOUT);
     }
 
-    private static class TestNetLinkMonitor extends SocketNetlinkMonitor {
-        TestNetLinkMonitor(@NonNull Handler handler,
+    private static class TestNetlinkMonitor extends SocketNetlinkMonitor {
+        TestNetlinkMonitor(@NonNull Handler handler,
                 @NonNull SharedLog log,
                 @Nullable MdnsSocketProvider.NetLinkMonitorCallBack cb) {
             super(handler, log, cb);
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/util/MdnsUtilsTest.kt b/tests/unit/java/com/android/server/connectivity/mdns/util/MdnsUtilsTest.kt
new file mode 100644
index 0000000..f584ed5
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/util/MdnsUtilsTest.kt
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License")
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns.util
+
+import android.os.Build
+import com.android.server.connectivity.mdns.util.MdnsUtils.equalsIgnoreDnsCase
+import com.android.server.connectivity.mdns.util.MdnsUtils.toDnsLowerCase
+import com.android.testutils.DevSdkIgnoreRule
+import com.android.testutils.DevSdkIgnoreRunner
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(DevSdkIgnoreRunner::class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
+class MdnsUtilsTest {
+    @Test
+    fun testToDnsLowerCase() {
+        assertEquals("test", toDnsLowerCase("TEST"))
+        assertEquals("test", toDnsLowerCase("TeSt"))
+        assertEquals("test", toDnsLowerCase("test"))
+        assertEquals("tÉst", toDnsLowerCase("TÉST"))
+        assertEquals("ţést", toDnsLowerCase("ţést"))
+        // Unicode characters 0x10000 (𐀀), 0x10001 (𐀁), 0x10041 (𐁁)
+        // Note the last 2 bytes of 0x10041 are identical to 'A', but it should remain unchanged.
+        assertEquals("test: -->\ud800\udc00 \ud800\udc01 \ud800\udc41<-- ",
+                toDnsLowerCase("Test: -->\ud800\udc00 \ud800\udc01 \ud800\udc41<-- "))
+        // Also test some characters where the first surrogate is not \ud800
+        assertEquals("test: >\ud83c\udff4\udb40\udc67\udb40\udc62\udb40" +
+                "\udc77\udb40\udc6c\udb40\udc73\udb40\udc7f<",
+                toDnsLowerCase("Test: >\ud83c\udff4\udb40\udc67\udb40\udc62\udb40" +
+                        "\udc77\udb40\udc6c\udb40\udc73\udb40\udc7f<"))
+    }
+
+    @Test
+    fun testEqualsIgnoreDnsCase() {
+        assertTrue(equalsIgnoreDnsCase("TEST", "Test"))
+        assertTrue(equalsIgnoreDnsCase("TEST", "test"))
+        assertTrue(equalsIgnoreDnsCase("test", "TeSt"))
+        assertTrue(equalsIgnoreDnsCase("Tést", "tést"))
+        assertFalse(equalsIgnoreDnsCase("ŢÉST", "ţést"))
+        // Unicode characters 0x10000 (𐀀), 0x10001 (𐀁), 0x10041 (𐁁)
+        // Note the last 2 bytes of 0x10041 are identical to 'A', but it should remain unchanged.
+        assertTrue(equalsIgnoreDnsCase("test: -->\ud800\udc00 \ud800\udc01 \ud800\udc41<-- ",
+                "Test: -->\ud800\udc00 \ud800\udc01 \ud800\udc41<-- "))
+        // Also test some characters where the first surrogate is not \ud800
+        assertTrue(equalsIgnoreDnsCase("test: >\ud83c\udff4\udb40\udc67\udb40\udc62\udb40" +
+                "\udc77\udb40\udc6c\udb40\udc73\udb40\udc7f<",
+                "Test: >\ud83c\udff4\udb40\udc67\udb40\udc62\udb40" +
+                        "\udc77\udb40\udc6c\udb40\udc73\udb40\udc7f<"))
+    }
+}