diff --git a/tests/cts/hostside/aidl/Android.mk b/tests/cts/hostside/aidl/Android.mk
index 85f71c3..20dabc1 100644
--- a/tests/cts/hostside/aidl/Android.mk
+++ b/tests/cts/hostside/aidl/Android.mk
@@ -19,6 +19,7 @@
 LOCAL_SDK_VERSION := current
 LOCAL_SRC_FILES := \
         com/android/cts/net/hostside/IMyService.aidl \
+        com/android/cts/net/hostside/INetworkCallback.aidl \
         com/android/cts/net/hostside/INetworkStateObserver.aidl \
         com/android/cts/net/hostside/IRemoteSocketFactory.aidl
 LOCAL_MODULE := CtsHostsideNetworkTestsAidl
diff --git a/tests/cts/hostside/aidl/com/android/cts/net/hostside/IMyService.aidl b/tests/cts/hostside/aidl/com/android/cts/net/hostside/IMyService.aidl
index 72d1059..a820ae5 100644
--- a/tests/cts/hostside/aidl/com/android/cts/net/hostside/IMyService.aidl
+++ b/tests/cts/hostside/aidl/com/android/cts/net/hostside/IMyService.aidl
@@ -16,10 +16,13 @@
 
 package com.android.cts.net.hostside;
 
+import com.android.cts.net.hostside.INetworkCallback;
+
 interface IMyService {
     void registerBroadcastReceiver();
     int getCounters(String receiverName, String action);
     String checkNetworkStatus();
     String getRestrictBackgroundStatus();
     void sendNotification(int notificationId, String notificationType);
+    void registerNetworkCallback(in INetworkCallback cb);
 }
diff --git a/tests/cts/hostside/aidl/com/android/cts/net/hostside/INetworkCallback.aidl b/tests/cts/hostside/aidl/com/android/cts/net/hostside/INetworkCallback.aidl
new file mode 100644
index 0000000..740ec26
--- /dev/null
+++ b/tests/cts/hostside/aidl/com/android/cts/net/hostside/INetworkCallback.aidl
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2019 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.cts.net.hostside;
+
+import android.net.Network;
+
+interface INetworkCallback {
+    void onBlockedStatusChanged(in Network network, boolean blocked);
+    void onAvailable(in Network network);
+    void onLost(in Network network);
+}
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
index c6e80a2..4e4d1f6 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
@@ -373,6 +373,23 @@
     }
 
     /**
+     * As per CDD requirements, if the device doesn't support data saver mode then
+     * ConnectivityManager.getRestrictBackgroundStatus() will always return
+     * RESTRICT_BACKGROUND_STATUS_DISABLED. So, enable the data saver mode and check if
+     * ConnectivityManager.getRestrictBackgroundStatus() for an app in background returns
+     * RESTRICT_BACKGROUND_STATUS_DISABLED or not.
+     */
+    protected boolean isDataSaverSupported() throws Exception {
+        assertMyRestrictBackgroundStatus(RESTRICT_BACKGROUND_STATUS_DISABLED);
+        try {
+            setRestrictBackground(true);
+            return !isMyRestrictBackgroundStatus(RESTRICT_BACKGROUND_STATUS_DISABLED);
+        } finally {
+            setRestrictBackground(false);
+        }
+    }
+
+    /**
      * Returns whether an app state should be considered "background" for restriction purposes.
      */
     protected boolean isBackground(int state) {
@@ -979,6 +996,10 @@
         fail("app2 receiver is not ready");
     }
 
+    protected void registerNetworkCallback(INetworkCallback cb) throws Exception {
+        mServiceClient.registerNetworkCallback(cb);
+    }
+
     /**
      * Registers a {@link NotificationListenerService} implementation that will execute the
      * notification actions right after the notification is sent.
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/DataSaverModeTest.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/DataSaverModeTest.java
index 599a31c..72563d4 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/DataSaverModeTest.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/DataSaverModeTest.java
@@ -73,23 +73,6 @@
         return mIsDataSaverSupported && super.isSupported();
     }
 
-    /**
-     * As per CDD requirements, if the device doesn't support data saver mode then
-     * ConnectivityManager.getRestrictBackgroundStatus() will always return
-     * RESTRICT_BACKGROUND_STATUS_DISABLED. So, enable the data saver mode and check if
-     * ConnectivityManager.getRestrictBackgroundStatus() for an app in background returns
-     * RESTRICT_BACKGROUND_STATUS_DISABLED or not.
-     */
-    private boolean isDataSaverSupported() throws Exception {
-        assertMyRestrictBackgroundStatus(RESTRICT_BACKGROUND_STATUS_DISABLED);
-        try {
-            setRestrictBackground(true);
-            return !isMyRestrictBackgroundStatus(RESTRICT_BACKGROUND_STATUS_DISABLED);
-        } finally {
-            setRestrictBackground(false);
-        }
-    }
-
     public void testGetRestrictBackgroundStatus_disabled() throws Exception {
         if (!isSupported()) return;
 
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyServiceClient.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyServiceClient.java
index e2976c2..3ee7b99 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyServiceClient.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyServiceClient.java
@@ -26,8 +26,6 @@
 
 import com.android.cts.net.hostside.IMyService;
 
-import java.io.FileDescriptor;
-
 public class MyServiceClient {
     private static final int TIMEOUT_MS = 5000;
     private static final String PACKAGE = MyServiceClient.class.getPackage().getName();
@@ -98,4 +96,8 @@
     public void sendNotification(int notificationId, String notificationType) throws RemoteException {
         mService.sendNotification(notificationId, notificationType);
     }
+
+    public void registerNetworkCallback(INetworkCallback cb) throws RemoteException {
+        mService.registerNetworkCallback(cb);
+    }
 }
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java
new file mode 100644
index 0000000..24dde9d
--- /dev/null
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2019 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.cts.net.hostside;
+
+import android.net.Network;
+
+import java.util.Objects;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+public class NetworkCallbackTest extends AbstractRestrictBackgroundNetworkTestCase {
+
+    private boolean mIsDataSaverSupported;
+    private Network mNetwork;
+    private final TestNetworkCallback mTestNetworkCallback = new TestNetworkCallback();
+
+    enum CallbackState {
+        NONE,
+        AVAILABLE,
+        LOST,
+        BLOCKED_STATUS
+    }
+
+    private static class CallbackInfo {
+        public final CallbackState state;
+        public final Network network;
+        public final Object arg;
+
+        CallbackInfo(CallbackState s, Network n, Object o) {
+            state = s; network = n; arg = o;
+        }
+
+        public String toString() {
+            return String.format("%s (%s) (%s)", state, network, arg);
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (!(o instanceof CallbackInfo)) return false;
+            // Ignore timeMs, since it's unpredictable.
+            final CallbackInfo other = (CallbackInfo) o;
+            return (state == other.state) && Objects.equals(network, other.network)
+                    && Objects.equals(arg, other.arg);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(state, network, arg);
+        }
+    }
+
+    private class TestNetworkCallback extends INetworkCallback.Stub {
+        private static final int TEST_CALLBACK_TIMEOUT_MS = 200;
+
+        private final LinkedBlockingQueue<CallbackInfo> mCallbacks = new LinkedBlockingQueue<>();
+
+        protected void setLastCallback(CallbackState state, Network network, Object o) {
+            mCallbacks.offer(new CallbackInfo(state, network, o));
+        }
+
+        CallbackInfo nextCallback(int timeoutMs) {
+            CallbackInfo cb = null;
+            try {
+                cb = mCallbacks.poll(timeoutMs, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e) {
+            }
+            if (cb == null) {
+                fail("Did not receive callback after " + timeoutMs + "ms");
+            }
+            return cb;
+        }
+
+        CallbackInfo expectCallback(CallbackState state, Network expectedNetwork, Object o) {
+            final CallbackInfo expected = new CallbackInfo(state, expectedNetwork, o);
+            final CallbackInfo actual = nextCallback(TEST_CALLBACK_TIMEOUT_MS);
+            assertEquals("Unexpected callback:", expected, actual);
+            return actual;
+        }
+
+        @Override
+        public void onAvailable(Network network) {
+            setLastCallback(CallbackState.AVAILABLE, network, null);
+        }
+
+        @Override
+        public void onLost(Network network) {
+            setLastCallback(CallbackState.LOST, network, null);
+        }
+
+        @Override
+        public void onBlockedStatusChanged(Network network, boolean blocked) {
+            setLastCallback(CallbackState.BLOCKED_STATUS, network, blocked);
+        }
+
+        public void expectLostCallback(Network expectedNetwork) {
+            expectCallback(CallbackState.LOST, expectedNetwork, null);
+        }
+
+        public void expectAvailableCallback(Network expectedNetwork) {
+            expectCallback(CallbackState.AVAILABLE, expectedNetwork, null);
+        }
+
+        public void expectBlockedStatusCallback(Network expectedNetwork, boolean expectBlocked) {
+            expectCallback(CallbackState.BLOCKED_STATUS, expectedNetwork,
+                    expectBlocked);
+        }
+
+        void assertNoCallback() {
+            CallbackInfo cb = null;
+            try {
+                cb = mCallbacks.poll(TEST_CALLBACK_TIMEOUT_MS, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e) {
+                // Expected.
+            }
+            if (cb != null) {
+                assertNull("Unexpected callback: " + cb, cb);
+            }
+        }
+    }
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+
+        mIsDataSaverSupported = isDataSaverSupported();
+
+        mNetwork = mCm.getActiveNetwork();
+
+        // Set initial state.
+        setBatterySaverMode(false);
+        registerBroadcastReceiver();
+
+        if (!mIsDataSaverSupported) return;
+        setRestrictBackground(false);
+        removeRestrictBackgroundWhitelist(mUid);
+        removeRestrictBackgroundBlacklist(mUid);
+        assertRestrictBackgroundChangedReceived(0);
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        super.tearDown();
+
+        if (!mIsDataSaverSupported) return;
+
+        try {
+            resetMeteredNetwork();
+        } finally {
+            setRestrictBackground(false);
+        }
+    }
+
+    public void testOnBlockedStatusChanged_data_saver() throws Exception {
+        if (!mIsDataSaverSupported) return;
+
+        // Prepare metered wifi
+        if (!setMeteredNetwork()) return;
+
+        // Register callback
+        registerNetworkCallback((INetworkCallback.Stub) mTestNetworkCallback);
+        mTestNetworkCallback.expectAvailableCallback(mNetwork);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+
+        // Enable restrict background
+        setRestrictBackground(true);
+        assertBackgroundNetworkAccess(false);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, true);
+
+        // Add to whitelist
+        addRestrictBackgroundWhitelist(mUid);
+        assertBackgroundNetworkAccess(true);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+
+        // Remove from whitelist
+        removeRestrictBackgroundWhitelist(mUid);
+        assertBackgroundNetworkAccess(false);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, true);
+
+        // Set to non-metered network
+        setUnmeteredNetwork();
+        assertBackgroundNetworkAccess(true);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+
+        // Disable restrict background, should not trigger callback
+        setRestrictBackground(false);
+        assertBackgroundNetworkAccess(true);
+        mTestNetworkCallback.assertNoCallback();
+    }
+
+
+    public void testOnBlockedStatusChanged_power_saver() throws Exception {
+        // Prepare metered wifi
+        if (!setMeteredNetwork()) return;
+
+        // Register callback
+        registerNetworkCallback((INetworkCallback.Stub) mTestNetworkCallback);
+        mTestNetworkCallback.expectAvailableCallback(mNetwork);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+
+        // Enable Power Saver
+        setBatterySaverMode(true);
+        assertBackgroundNetworkAccess(false);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, true);
+
+        // Disable Power Saver
+        setBatterySaverMode(false);
+        assertBackgroundNetworkAccess(true);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+
+        // Set to non-metered network
+        setUnmeteredNetwork();
+        mTestNetworkCallback.assertNoCallback();
+
+        // Enable Power Saver
+        setBatterySaverMode(true);
+        assertBackgroundNetworkAccess(false);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, true);
+
+        // Disable Power Saver
+        setBatterySaverMode(false);
+        assertBackgroundNetworkAccess(true);
+        mTestNetworkCallback.expectBlockedStatusCallback(mNetwork, false);
+    }
+
+    // TODO: 1. test against VPN lockdown.
+    //       2. test against multiple networks.
+}
diff --git a/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyService.java b/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyService.java
index 2496c4a..ec536af 100644
--- a/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyService.java
+++ b/tests/cts/hostside/app2/src/com/android/cts/net/hostside/app2/MyService.java
@@ -16,6 +16,7 @@
 package com.android.cts.net.hostside.app2;
 
 import static android.net.ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED;
+
 import static com.android.cts.net.hostside.app2.Common.ACTION_RECEIVER_READY;
 import static com.android.cts.net.hostside.app2.Common.DYNAMIC_RECEIVER;
 import static com.android.cts.net.hostside.app2.Common.TAG;
@@ -26,13 +27,16 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.content.SharedPreferences;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkRequest;
 import android.os.IBinder;
-import android.os.Looper;
+import android.os.RemoteException;
 import android.util.Log;
-import android.widget.Toast;
 
 import com.android.cts.net.hostside.IMyService;
+import com.android.cts.net.hostside.INetworkCallback;
 
 /**
  * Service used to dynamically register a broadcast receiver.
@@ -40,7 +44,10 @@
 public class MyService extends Service {
     private static final String NOTIFICATION_CHANNEL_ID = "MyService";
 
+    ConnectivityManager mCm;
+
     private MyBroadcastReceiver mReceiver;
+    private ConnectivityManager.NetworkCallback mNetworkCallback;
 
     // TODO: move MyBroadcast static functions here - they were kept there to make git diff easier.
 
@@ -81,8 +88,67 @@
             MyBroadcastReceiver .sendNotification(getApplicationContext(), NOTIFICATION_CHANNEL_ID,
                     notificationId, notificationType);
         }
+
+        @Override
+        public void registerNetworkCallback(INetworkCallback cb) {
+            if (mNetworkCallback != null) {
+                Log.d(TAG, "unregister previous network callback: " + mNetworkCallback);
+                unregisterNetworkCallback();
+            }
+            Log.d(TAG, "registering network callback");
+
+            mNetworkCallback = new ConnectivityManager.NetworkCallback() {
+                @Override
+                public void onBlockedStatusChanged(Network network, boolean blocked) {
+                    try {
+                        cb.onBlockedStatusChanged(network, blocked);
+                    } catch (RemoteException e) {
+                        Log.d(TAG, "Cannot send onBlockedStatusChanged: " + e);
+                        unregisterNetworkCallback();
+                    }
+                }
+
+                @Override
+                public void onAvailable(Network network) {
+                    try {
+                        cb.onAvailable(network);
+                    } catch (RemoteException e) {
+                        Log.d(TAG, "Cannot send onAvailable: " + e);
+                        unregisterNetworkCallback();
+                    }
+                }
+
+                @Override
+                public void onLost(Network network) {
+                    try {
+                        cb.onLost(network);
+                    } catch (RemoteException e) {
+                        Log.d(TAG, "Cannot send onLost: " + e);
+                        unregisterNetworkCallback();
+                    }
+                }
+            };
+            mCm.registerNetworkCallback(makeWifiNetworkRequest(), mNetworkCallback);
+            try {
+                cb.asBinder().linkToDeath(() -> unregisterNetworkCallback(), 0);
+            } catch (RemoteException e) {
+                unregisterNetworkCallback();
+            }
+        }
       };
 
+    private void unregisterNetworkCallback() {
+        Log.d(TAG, "unregistering network callback");
+        mCm.unregisterNetworkCallback(mNetworkCallback);
+        mNetworkCallback = null;
+    }
+
+    private NetworkRequest makeWifiNetworkRequest() {
+        return new NetworkRequest.Builder()
+                .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
+                .build();
+    }
+
     @Override
     public IBinder onBind(Intent intent) {
         return mBinder;
@@ -94,6 +160,8 @@
         ((NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE))
                 .createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID,
                         NOTIFICATION_CHANNEL_ID, NotificationManager.IMPORTANCE_DEFAULT));
+        mCm = (ConnectivityManager) getApplicationContext()
+                .getSystemService(Context.CONNECTIVITY_SERVICE);
     }
 
     @Override
diff --git a/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkCallbackTests.java b/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkCallbackTests.java
new file mode 100644
index 0000000..8d6c4ac
--- /dev/null
+++ b/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkCallbackTests.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 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.cts.net;
+public class HostsideNetworkCallbackTests extends HostsideNetworkTestCase {
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        uninstallPackage(TEST_APP2_PKG, false);
+        installPackage(TEST_APP2_APK);
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        super.tearDown();
+        uninstallPackage(TEST_APP2_PKG, true);
+    }
+
+    public void testOnBlockedStatusChanged_data_saver() throws Exception {
+        runDeviceTests(TEST_PKG,
+                TEST_PKG + ".NetworkCallbackTest", "testOnBlockedStatusChanged_data_saver");
+    }
+
+    public void testOnBlockedStatusChanged_power_saver() throws Exception {
+        runDeviceTests(TEST_PKG,
+                TEST_PKG + ".NetworkCallbackTest", "testOnBlockedStatusChanged_power_saver");
+    }
+}
+