diff --git a/src/com/android/phone/PhoneGlobals.java b/src/com/android/phone/PhoneGlobals.java
index 2f372ce..76cf979 100644
--- a/src/com/android/phone/PhoneGlobals.java
+++ b/src/com/android/phone/PhoneGlobals.java
@@ -994,6 +994,11 @@
         }
 
         ServiceState serviceState = phone.getServiceState();
+        if (serviceState == null) {
+            Log.e(LOG_TAG, "updateDataRoamingStatus: serviceState is null");
+            return;
+        }
+
         String roamingNumeric = serviceState.getOperatorNumeric();
         String roamingNumericReason = "RoamingNumeric=" + roamingNumeric;
         String callingReason = "CallingReason=" + reason;
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index ec85361..d8d8450 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -23,6 +23,9 @@
 import static android.telephony.TelephonyManager.ENABLE_FEATURE_MAPPING;
 import static android.telephony.TelephonyManager.HAL_SERVICE_NETWORK;
 import static android.telephony.TelephonyManager.HAL_SERVICE_RADIO;
+import static android.telephony.satellite.SatelliteManager.KEY_SATELLITE_COMMUNICATION_ALLOWED;
+import static android.telephony.satellite.SatelliteManager.SATELLITE_RESULT_ACCESS_BARRED;
+import static android.telephony.satellite.SatelliteManager.SATELLITE_RESULT_SUCCESS;
 
 import static com.android.internal.telephony.PhoneConstants.PHONE_TYPE_CDMA;
 import static com.android.internal.telephony.PhoneConstants.PHONE_TYPE_GSM;
@@ -210,6 +213,7 @@
 import com.android.internal.telephony.SmsApplication;
 import com.android.internal.telephony.SmsController;
 import com.android.internal.telephony.SmsPermissions;
+import com.android.internal.telephony.TelephonyCountryDetector;
 import com.android.internal.telephony.TelephonyIntents;
 import com.android.internal.telephony.TelephonyPermissions;
 import com.android.internal.telephony.data.DataUtils;
@@ -243,6 +247,7 @@
 import com.android.phone.callcomposer.CallComposerPictureManager;
 import com.android.phone.callcomposer.CallComposerPictureTransfer;
 import com.android.phone.callcomposer.ImageData;
+import com.android.phone.satellite.accesscontrol.SatelliteAccessController;
 import com.android.phone.settings.PickSmsSubscriptionActivity;
 import com.android.phone.slice.SlicePurchaseController;
 import com.android.phone.utils.CarrierAllowListInfo;
@@ -417,6 +422,7 @@
     private final ImsResolver mImsResolver;
 
     private final SatelliteController mSatelliteController;
+    private final SatelliteAccessController mSatelliteAccessController;
     private final UserManager mUserManager;
     private final AppOpsManager mAppOps;
     private final MainThreadHandler mMainThreadHandler;
@@ -2464,6 +2470,8 @@
         mRadioInterfaceCapabilities = RadioInterfaceCapabilityController.getInstance();
         mNotifyUserActivity = new AtomicBoolean(false);
         mPackageManager = app.getPackageManager();
+        mSatelliteAccessController = SatelliteAccessController.getOrCreateInstance(
+                getDefaultPhone().getContext(), featureFlags);
         PropertyInvalidatedCache.invalidateCache(TelephonyManager.CACHE_KEY_PHONE_ACCOUNT_TO_SUBID);
         publish();
         CarrierAllowListInfo.loadInstance(mApp);
@@ -12956,8 +12964,34 @@
     public void requestSatelliteEnabled(int subId, boolean enableSatellite, boolean enableDemoMode,
             @NonNull IIntegerConsumer callback) {
         enforceSatelliteCommunicationPermission("requestSatelliteEnabled");
-        mSatelliteController.requestSatelliteEnabled(subId, enableSatellite, enableDemoMode,
-                callback);
+        ResultReceiver resultReceiver = new ResultReceiver(mMainThreadHandler) {
+            @Override
+            protected void onReceiveResult(int resultCode, Bundle resultData) {
+                Log.d(LOG_TAG, "Satellite access restriction resultCode=" + resultCode
+                        + ", resultData=" + resultData);
+                boolean isAllowed = false;
+                Consumer<Integer> result = FunctionalUtils.ignoreRemoteException(callback::accept);
+                if (resultCode == SATELLITE_RESULT_SUCCESS) {
+                    if (resultData != null
+                            && resultData.containsKey(KEY_SATELLITE_COMMUNICATION_ALLOWED)) {
+                        isAllowed = resultData.getBoolean(KEY_SATELLITE_COMMUNICATION_ALLOWED);
+                    } else {
+                        loge("KEY_SATELLITE_COMMUNICATION_ALLOWED does not exist.");
+                    }
+                } else {
+                    result.accept(resultCode);
+                    return;
+                }
+                if (isAllowed) {
+                    mSatelliteController.requestSatelliteEnabled(
+                            subId, enableSatellite, enableDemoMode, callback);
+                } else {
+                    result.accept(SATELLITE_RESULT_ACCESS_BARRED);
+                }
+            }
+        };
+        mSatelliteAccessController.requestIsSatelliteCommunicationAllowedForCurrentLocation(
+                subId, resultReceiver);
     }
 
     /**
@@ -13278,8 +13312,8 @@
             @NonNull ResultReceiver result) {
         enforceSatelliteCommunicationPermission(
                 "requestIsSatelliteCommunicationAllowedForCurrentLocation");
-        mSatelliteController.requestIsSatelliteCommunicationAllowedForCurrentLocation(subId,
-                result);
+        mSatelliteAccessController.requestIsSatelliteCommunicationAllowedForCurrentLocation(
+                subId, result);
     }
 
     /**
@@ -13611,6 +13645,55 @@
     }
 
     /**
+     * This API should be used by only CTS tests to forcefully set telephony country codes.
+     *
+     * @return {@code true} if the country code is set successfully, {@code false} otherwise.
+     */
+    public boolean setCountryCodes(boolean reset, List<String> currentNetworkCountryCodes,
+            Map cachedNetworkCountryCodes, String locationCountryCode,
+            long locationCountryCodeTimestampNanos) {
+        Log.d(LOG_TAG, "setCountryCodes: currentNetworkCountryCodes="
+                + String.join(", ", currentNetworkCountryCodes)
+                + ", locationCountryCode=" + locationCountryCode
+                + ", locationCountryCodeTimestampNanos" + locationCountryCodeTimestampNanos
+                + ", reset=" + reset + ", cachedNetworkCountryCodes="
+                + String.join(", ", cachedNetworkCountryCodes.keySet()));
+        TelephonyPermissions.enforceShellOnly(
+                Binder.getCallingUid(), "setCachedLocationCountryCode");
+        TelephonyPermissions.enforceCallingOrSelfModifyPermissionOrCarrierPrivilege(mApp,
+                SubscriptionManager.INVALID_SUBSCRIPTION_ID,
+                "setCachedLocationCountryCode");
+        return TelephonyCountryDetector.getInstance(getDefaultPhone().getContext()).setCountryCodes(
+                reset, currentNetworkCountryCodes, cachedNetworkCountryCodes, locationCountryCode,
+                locationCountryCodeTimestampNanos);
+    }
+
+    /**
+     * This API should be used by only CTS tests to override the overlay configs of satellite
+     * access controller.
+     *
+     * @param reset {@code true} mean the overridden configs should not be used, {@code false}
+     *              otherwise.
+     * @return {@code true} if the overlay configs are set successfully, {@code false} otherwise.
+     */
+    public boolean setSatelliteAccessControlOverlayConfigs(boolean reset, boolean isAllowed,
+            String s2CellFile, long locationFreshDurationNanos,
+            List<String> satelliteCountryCodes) {
+        Log.d(LOG_TAG, "setSatelliteAccessControlOverlayConfigs: reset=" + reset
+                + ", isAllowed" + isAllowed + ", s2CellFile=" + s2CellFile
+                + ", locationFreshDurationNanos=" + locationFreshDurationNanos
+                + ", satelliteCountryCodes=" + ((satelliteCountryCodes != null)
+                ? String.join(", ", satelliteCountryCodes) : null));
+        TelephonyPermissions.enforceShellOnly(
+                Binder.getCallingUid(), "setSatelliteAccessControlOverlayConfigs");
+        TelephonyPermissions.enforceCallingOrSelfModifyPermissionOrCarrierPrivilege(mApp,
+                SubscriptionManager.INVALID_SUBSCRIPTION_ID,
+                "setSatelliteAccessControlOverlayConfigs");
+        return mSatelliteAccessController.setSatelliteAccessControlOverlayConfigs(reset, isAllowed,
+                s2CellFile, locationFreshDurationNanos, satelliteCountryCodes);
+    }
+
+    /**
      * This API can be used by only CTS to override the cached value for the device overlay config
      * value : config_send_satellite_datagram_to_modem_in_demo_mode, which determines whether
      * outgoing satellite datagrams should be sent to modem in demo mode.
diff --git a/src/com/android/phone/TelephonyShellCommand.java b/src/com/android/phone/TelephonyShellCommand.java
index 5986a7c..80b7cf6 100644
--- a/src/com/android/phone/TelephonyShellCommand.java
+++ b/src/com/android/phone/TelephonyShellCommand.java
@@ -24,6 +24,8 @@
 import static java.util.Map.entry;
 
 import android.Manifest;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.content.Context;
 import android.net.Uri;
 import android.os.Binder;
@@ -65,6 +67,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -191,6 +194,9 @@
             "set-satellite-device-aligned-timeout-duration";
     private static final String SET_EMERGENCY_CALL_TO_SATELLITE_HANDOVER_TYPE =
             "set-emergency-call-to-satellite-handover-type";
+    private static final String SET_COUNTRY_CODES = "set-country-codes";
+    private static final String SET_SATELLITE_ACCESS_CONTROL_OVERLAY_CONFIGS =
+            "set-satellite-access-control-overlay-configs";
     private static final String SET_SHOULD_SEND_DATAGRAM_TO_MODEM_IN_DEMO_MODE =
             "set-should-send-datagram-to-modem-in-demo-mode";
 
@@ -388,6 +394,10 @@
                 return handleSetEmergencyCallToSatelliteHandoverType();
             case SET_SHOULD_SEND_DATAGRAM_TO_MODEM_IN_DEMO_MODE:
                 return handleSetShouldSendDatagramToModemInDemoMode();
+            case SET_SATELLITE_ACCESS_CONTROL_OVERLAY_CONFIGS:
+                return handleSetSatelliteAccessControlOverlayConfigs();
+            case SET_COUNTRY_CODES:
+                return handleSetCountryCodes();
             default: {
                 return handleDefaultCommands(cmd);
             }
@@ -795,6 +805,25 @@
         pw.println("          If no option is specified, override is disabled.");
         pw.println("      -d: the delay in seconds in sending EVENT_DISPLAY_EMERGENCY_MESSAGE.");
         pw.println("          If no option is specified, there is no delay in sending the event.");
+        pw.println("  set-satellite-access-control-overlay-configs [-r -a -f SATELLITE_S2_FILE ");
+        pw.println("    -d LOCATION_FRESH_DURATION_NANOS -c COUNTRY_CODES] Override the overlay");
+        pw.println("    configs of satellite access controller.");
+        pw.println("    Options are:");
+        pw.println("      -r: clear the overriding. Absent means enable overriding.");
+        pw.println("      -a: the country codes is an allowed list. Absent means disallowed.");
+        pw.println("      -f: the satellite s2 file.");
+        pw.println("      -d: the location fresh duration nanos.");
+        pw.println("      -c: the list of satellite country codes separated by comma.");
+        pw.println("  set-country-codes [-r -n CURRENT_NETWORK_COUNTRY_CODES -c");
+        pw.println("    CACHED_NETWORK_COUNTRY_CODES -l LOCATION_COUNTRY_CODE -t");
+        pw.println("    LOCATION_COUNTRY_CODE_TIMESTAMP] ");
+        pw.println("    Override the cached location country code and its update timestamp. ");
+        pw.println("    Options are:");
+        pw.println("      -r: clear the overriding. Absent means enable overriding.");
+        pw.println("      -n: the current network country code ISOs.");
+        pw.println("      -c: the cached network country code ISOs.");
+        pw.println("      -l: the location country code ISO.");
+        pw.println("      -t: the update timestamp nanos of the location country code.");
     }
 
     private void onHelpImei() {
@@ -3394,6 +3423,149 @@
         return 0;
     }
 
+    private int handleSetSatelliteAccessControlOverlayConfigs() {
+        PrintWriter errPw = getErrPrintWriter();
+        boolean reset = false;
+        boolean isAllowed = false;
+        String s2CellFile = null;
+        long locationFreshDurationNanos = 0;
+        List<String> satelliteCountryCodes = null;
+
+        String opt;
+        while ((opt = getNextOption()) != null) {
+            switch (opt) {
+                case "-r": {
+                    reset = true;
+                    break;
+                }
+                case "-a": {
+                    isAllowed = true;
+                    break;
+                }
+                case "-f": {
+                    s2CellFile = getNextArgRequired();
+                    break;
+                }
+                case "-d": {
+                    locationFreshDurationNanos = Long.parseLong(getNextArgRequired());
+                    break;
+                }
+                case "-c": {
+                    String countryCodeStr = getNextArgRequired();
+                    satelliteCountryCodes = Arrays.asList(countryCodeStr.split(","));
+                    break;
+                }
+            }
+        }
+        Log.d(LOG_TAG, "handleSetSatelliteAccessControlOverlayConfigs: reset=" + reset
+                + ", isAllowed=" + isAllowed + ", s2CellFile=" + s2CellFile
+                + ", locationFreshDurationNanos=" + locationFreshDurationNanos
+                + ", satelliteCountryCodes=" + satelliteCountryCodes);
+
+        try {
+            boolean result = mInterface.setSatelliteAccessControlOverlayConfigs(reset, isAllowed,
+                    s2CellFile, locationFreshDurationNanos, satelliteCountryCodes);
+            if (VDBG) {
+                Log.v(LOG_TAG, "setSatelliteAccessControlOverlayConfigs result =" + result);
+            }
+            getOutPrintWriter().println(result);
+        } catch (RemoteException e) {
+            Log.e(LOG_TAG, "setSatelliteAccessControlOverlayConfigs: ex=" + e.getMessage());
+            errPw.println("Exception: " + e.getMessage());
+            return -1;
+        }
+        return 0;
+    }
+
+    private int handleSetCountryCodes() {
+        PrintWriter errPw = getErrPrintWriter();
+        List<String> currentNetworkCountryCodes = new ArrayList<>();
+        String locationCountryCode = null;
+        long locationCountryCodeTimestampNanos = 0;
+        Map<String, Long> cachedNetworkCountryCodes = new HashMap<>();
+        boolean reset = false;
+
+        String opt;
+        while ((opt = getNextOption()) != null) {
+            switch (opt) {
+                case "-r": {
+                    reset = true;
+                    break;
+                }
+                case "-n": {
+                    String countryCodeStr = getNextArgRequired();
+                    currentNetworkCountryCodes = Arrays.asList(countryCodeStr.split(","));
+                    break;
+                }
+                case "-c": {
+                    String cachedNetworkCountryCodeStr = getNextArgRequired();
+                    cachedNetworkCountryCodes = parseStringLongMap(cachedNetworkCountryCodeStr);
+                    break;
+                }
+                case "-l": {
+                    locationCountryCode = getNextArgRequired();
+                    break;
+                }
+                case "-t": {
+                    locationCountryCodeTimestampNanos = Long.parseLong(getNextArgRequired());
+                    break;
+                }
+            }
+        }
+        Log.d(LOG_TAG, "setCountryCodes: locationCountryCode="
+                + locationCountryCode + ", locationCountryCodeTimestampNanos="
+                + locationCountryCodeTimestampNanos + ", currentNetworkCountryCodes="
+                + currentNetworkCountryCodes);
+
+        try {
+            boolean result = mInterface.setCountryCodes(reset, currentNetworkCountryCodes,
+                    cachedNetworkCountryCodes, locationCountryCode,
+                    locationCountryCodeTimestampNanos);
+            if (VDBG) {
+                Log.v(LOG_TAG, "setCountryCodes result =" + result);
+            }
+            getOutPrintWriter().println(result);
+        } catch (RemoteException e) {
+            Log.e(LOG_TAG, "setCountryCodes: ex=" + e.getMessage());
+            errPw.println("Exception: " + e.getMessage());
+            return -1;
+        }
+        return 0;
+    }
+
+    /**
+     * Sample inputStr = "US,UK,CA;2,1,3"
+     * Sample output: {[US,2], [UK,1], [CA,3]}
+     */
+    @NonNull private Map<String, Long> parseStringLongMap(@Nullable String inputStr) {
+        Map<String, Long> result = new HashMap<>();
+        if (!TextUtils.isEmpty(inputStr)) {
+            String[] stringLongArr = inputStr.split(";");
+            if (stringLongArr.length != 2) {
+                Log.e(LOG_TAG, "parseStringLongMap: invalid inputStr=" + inputStr);
+                return result;
+            }
+
+            String[] stringArr = stringLongArr[0].split(",");
+            String[] longArr = stringLongArr[1].split(",");
+            if (stringArr.length != longArr.length) {
+                Log.e(LOG_TAG, "parseStringLongMap: invalid inputStr=" + inputStr);
+                return result;
+            }
+
+            for (int i = 0; i < stringArr.length; i++) {
+                try {
+                    result.put(stringArr[i], Long.parseLong(longArr[i]));
+                } catch (Exception ex) {
+                    Log.e(LOG_TAG, "parseStringLongMap: invalid inputStr=" + inputStr
+                            + ", ex=" + ex);
+                    return result;
+                }
+            }
+        }
+        return result;
+    }
+
     private int handleCarrierRestrictionStatusCommand() {
         try {
             String MOCK_MODEM_SERVICE_NAME = "android.telephony.mockmodem.MockModemService";
diff --git a/src/com/android/phone/satellite/accesscontrol/S2RangeSatelliteOnDeviceAccessController.java b/src/com/android/phone/satellite/accesscontrol/S2RangeSatelliteOnDeviceAccessController.java
index 62fbd18..4490460 100644
--- a/src/com/android/phone/satellite/accesscontrol/S2RangeSatelliteOnDeviceAccessController.java
+++ b/src/com/android/phone/satellite/accesscontrol/S2RangeSatelliteOnDeviceAccessController.java
@@ -63,9 +63,9 @@
         return new S2RangeSatelliteOnDeviceAccessController(reader, s2Level);
     }
 
-    @Override
-    public LocationToken createLocationTokenForLatLng(double latDegrees, double lngDegrees) {
-        return new LocationTokenImpl(getS2CellId(latDegrees, lngDegrees).id());
+    public static LocationToken createLocationTokenForLatLng(
+            double latDegrees, double lngDegrees, int s2Level) {
+        return new LocationTokenImpl(getS2CellId(latDegrees, lngDegrees, s2Level).id());
     }
 
     @Override
@@ -78,6 +78,11 @@
         return isSatCommunicationAllowedAtLocation(locationTokenImpl.getS2CellId());
     }
 
+    @Override
+    public int getS2Level() {
+        return mS2Level;
+    }
+
     private boolean isSatCommunicationAllowedAtLocation(long s2CellId) throws IOException {
         S2LevelRange entry = mSatS2RangeFileReader.findEntryByCellId(s2CellId);
         if (mSatS2RangeFileReader.isAllowedList()) {
@@ -91,12 +96,12 @@
         }
     }
 
-    private S2CellId getS2CellId(double latDegrees, double lngDegrees) {
+    private static S2CellId getS2CellId(double latDegrees, double lngDegrees, int s2Level) {
         // Create the leaf S2 cell containing the given S2LatLng
         S2CellId cellId = S2CellId.fromLatLng(S2LatLng.fromDegrees(latDegrees, lngDegrees));
 
         // Return the S2 cell at the expected S2 level
-        return cellId.parent(mS2Level);
+        return cellId.parent(s2Level);
     }
 
     @Override
diff --git a/src/com/android/phone/satellite/accesscontrol/SatelliteAccessController.java b/src/com/android/phone/satellite/accesscontrol/SatelliteAccessController.java
index 7f9c1aa..047c0a3 100644
--- a/src/com/android/phone/satellite/accesscontrol/SatelliteAccessController.java
+++ b/src/com/android/phone/satellite/accesscontrol/SatelliteAccessController.java
@@ -16,17 +16,62 @@
 
 package com.android.phone.satellite.accesscontrol;
 
+import static android.telephony.satellite.SatelliteManager.KEY_SATELLITE_COMMUNICATION_ALLOWED;
+import static android.telephony.satellite.SatelliteManager.SATELLITE_RESULT_REQUEST_NOT_SUPPORTED;
+import static android.telephony.satellite.SatelliteManager.SATELLITE_RESULT_SUCCESS;
+
+import android.annotation.ArrayRes;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.content.Context;
+import android.content.res.Resources;
+import android.location.Location;
+import android.location.LocationManager;
+import android.location.LocationRequest;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.CancellationSignal;
 import android.os.Handler;
+import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
 import android.os.ResultReceiver;
+import android.os.SystemClock;
+import android.os.SystemProperties;
+import android.provider.DeviceConfig;
+import android.telecom.TelecomManager;
+import android.telephony.AnomalyReporter;
 import android.telephony.Rlog;
-import android.telephony.satellite.SatelliteManager;
+import android.text.TextUtils;
+import android.util.Pair;
 
+import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.telephony.Phone;
+import com.android.internal.telephony.PhoneFactory;
+import com.android.internal.telephony.TelephonyCountryDetector;
 import com.android.internal.telephony.flags.FeatureFlags;
+import com.android.internal.telephony.satellite.SatelliteController;
+import com.android.phone.PhoneGlobals;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
 /**
  * This module is responsible for making sure that satellite communication can be used by devices
@@ -34,34 +79,141 @@
  */
 public class SatelliteAccessController extends Handler {
     private static final String TAG = "SatelliteAccessController";
+    /**
+     * UUID to report an anomaly when getting an exception in looking up on-device data for the
+     * current location.
+     */
+    private static final String UUID_ON_DEVICE_LOOKUP_EXCEPTION =
+            "dbea1641-630e-4780-9f25-8337ba6c3563";
+    /**
+     * UUID to report an anomaly when getting an exception in creating the on-device access
+     * controller.
+     */
+    private static final String UUID_CREATE_ON_DEVICE_ACCESS_CONTROLLER_EXCEPTION =
+            "3ac767d8-2867-4d60-97c2-ae9d378a5521";
+    protected static final long WAIT_FOR_CURRENT_LOCATION_TIMEOUT_MILLIS =
+            TimeUnit.SECONDS.toMillis(180);
+    protected static final long KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT_MILLIS =
+            TimeUnit.MINUTES.toMillis(30);
+    protected static final int DEFAULT_S2_LEVEL = 12;
+    private static final int DEFAULT_LOCATION_FRESH_DURATION_SECONDS = 600;
+    private static final boolean DEFAULT_SATELLITE_ACCESS_ALLOW = true;
+    private static final String ALLOW_MOCK_MODEM_PROPERTY = "persist.radio.allow_mock_modem";
+    private static final String BOOT_ALLOW_MOCK_MODEM_PROPERTY = "ro.boot.radio.allow_mock_modem";
+    private static final boolean DEBUG = !"user".equals(Build.TYPE);
+    private static final int MAX_CACHE_SIZE = 50;
 
     private static final int CMD_IS_SATELLITE_COMMUNICATION_ALLOWED = 1;
+    protected static final int EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT = 2;
+    protected static final int EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT = 3;
+
+    private static SatelliteAccessController sInstance;
 
     /** Feature flags to control behavior and errors. */
     @NonNull private final FeatureFlags mFeatureFlags;
-    @Nullable private final SatelliteOnDeviceAccessController mSatelliteOnDeviceAccessController;
+    @GuardedBy("mLock")
+    @Nullable protected SatelliteOnDeviceAccessController mSatelliteOnDeviceAccessController;
+    @NonNull private final LocationManager mLocationManager;
+    @NonNull private final TelecomManager mTelecomManager;
+    @NonNull private final TelephonyCountryDetector mCountryDetector;
+    @NonNull private final SatelliteController mSatelliteController;
+    @NonNull private final ResultReceiver mInternalSatelliteAllowResultReceiver;
+    @NonNull protected final Object mLock = new Object();
+    @GuardedBy("mLock")
+    @NonNull
+    private final Set<ResultReceiver> mSatelliteAllowResultReceivers = new HashSet<>();
+    @NonNull private List<String> mSatelliteCountryCodes;
+    private boolean mIsSatelliteAllowAccessControl;
+    @Nullable private File mSatelliteS2CellFile;
+    private long mLocationFreshDurationNanos;
+    @GuardedBy("mLock")
+    private boolean mIsOverlayConfigOverridden = false;
+    @NonNull private List<String> mOverriddenSatelliteCountryCodes;
+    private boolean mOverriddenIsSatelliteAllowAccessControl;
+    @Nullable private File mOverriddenSatelliteS2CellFile;
+    private long mOverriddenLocationFreshDurationNanos;
+    @GuardedBy("mLock")
+    @NonNull
+    private final Map<SatelliteOnDeviceAccessController.LocationToken, Boolean>
+            mCachedAccessRestrictionMap = new LinkedHashMap<>() {
+                @Override
+                protected boolean removeEldestEntry(
+                        Entry<SatelliteOnDeviceAccessController.LocationToken, Boolean> eldest) {
+                    return size() > MAX_CACHE_SIZE;
+                }
+            };
+    @GuardedBy("mLock")
+    @Nullable
+    CancellationSignal mLocationRequestCancellationSignal = null;
+    private int mS2Level = DEFAULT_S2_LEVEL;
+    @GuardedBy("mLock")
+    @Nullable private Location mFreshLastKnownLocation = null;
+
+    /** These are used for CTS test */
+    private Path mCtsSatS2FilePath = null;
+    private static final String GOOGLE_US_SAN_SAT_S2_FILE_NAME = "google_us_san_sat_s2.dat";
 
     /**
      * Create a SatelliteAccessController instance.
      *
+     * @param context The context associated with the {@link SatelliteAccessController} instance.
      * @param featureFlags The FeatureFlags that are supported.
+     * @param locationManager The LocationManager for querying current location of the device.
      * @param looper The Looper to run the SatelliteAccessController on.
-     * @param satelliteOnDeviceAccessController The location-based satellite restriction lookup.
+     * @param satelliteOnDeviceAccessController The on-device satellite access controller instance.
      */
     @VisibleForTesting(visibility = VisibleForTesting.Visibility.PRIVATE)
-    public SatelliteAccessController(@NonNull FeatureFlags featureFlags, @NonNull Looper looper,
-            @Nullable SatelliteOnDeviceAccessController satelliteOnDeviceAccessController) {
+    protected SatelliteAccessController(@NonNull Context context,
+            @NonNull FeatureFlags featureFlags, @NonNull Looper looper,
+            @NonNull LocationManager locationManager, @NonNull TelecomManager telecomManager,
+            @Nullable SatelliteOnDeviceAccessController satelliteOnDeviceAccessController,
+            @Nullable File s2CellFile) {
         super(looper);
         mFeatureFlags = featureFlags;
+        mLocationManager = locationManager;
+        mTelecomManager = telecomManager;
         mSatelliteOnDeviceAccessController = satelliteOnDeviceAccessController;
+        mCountryDetector = TelephonyCountryDetector.getInstance(context);
+        mSatelliteController = SatelliteController.getInstance();
+        loadOverlayConfigs(context);
+        if (s2CellFile != null) {
+            mSatelliteS2CellFile = s2CellFile;
+        }
+        mInternalSatelliteAllowResultReceiver = new ResultReceiver(this) {
+            @Override
+            protected void onReceiveResult(int resultCode, Bundle resultData) {
+                handleSatelliteAllowResultFromSatelliteController(resultCode, resultData);
+            }
+        };
+        // Init the SatelliteOnDeviceAccessController so that the S2 level can be cached
+        initSatelliteOnDeviceAccessController();
+    }
+
+    /** @return the singleton instance of {@link SatelliteAccessController} */
+    public static synchronized SatelliteAccessController getOrCreateInstance(
+            @NonNull Context context, @NonNull FeatureFlags featureFlags) {
+        if (sInstance == null) {
+            HandlerThread handlerThread = new HandlerThread("SatelliteAccessController");
+            handlerThread.start();
+            sInstance = new SatelliteAccessController(context, featureFlags,
+                    handlerThread.getLooper(), context.getSystemService(LocationManager.class),
+                    context.getSystemService(TelecomManager.class), null, null);
+        }
+        return sInstance;
     }
 
     @Override
     public void handleMessage(Message msg) {
         switch (msg.what) {
             case CMD_IS_SATELLITE_COMMUNICATION_ALLOWED:
-                handleRequestIsSatelliteCommunicationAllowedForCurrentLocation(
-                        (ResultReceiver) msg.obj);
+                handleCmdIsSatelliteAllowedForCurrentLocation(
+                        (Pair<Integer, ResultReceiver>) msg.obj);
+                break;
+            case EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT:
+                handleWaitForCurrentLocationTimedOutEvent();
+                break;
+            case EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT:
+                cleanupOnDeviceAccessControllerResources();
                 break;
             default:
                 logw("SatelliteAccessControllerHandler: unexpected message code: " + msg.what);
@@ -72,23 +224,677 @@
     /**
      * Request to get whether satellite communication is allowed for the current location.
      *
+     * @param subId The subId of the subscription to check whether satellite communication is
+     *              allowed for the current location for.
      * @param result The result receiver that returns whether satellite communication is allowed
      *               for the current location if the request is successful or an error code
      *               if the request failed.
      */
-    public void requestIsSatelliteCommunicationAllowedForCurrentLocation(
+    public void requestIsSatelliteCommunicationAllowedForCurrentLocation(int subId,
             @NonNull ResultReceiver result) {
         if (!mFeatureFlags.oemEnabledSatelliteFlag()) {
             logd("oemEnabledSatelliteFlag is disabled");
-            result.send(SatelliteManager.SATELLITE_RESULT_REQUEST_NOT_SUPPORTED, null);
+            result.send(SATELLITE_RESULT_REQUEST_NOT_SUPPORTED, null);
             return;
         }
-        sendRequestAsync(CMD_IS_SATELLITE_COMMUNICATION_ALLOWED, result);
+        sendRequestAsync(CMD_IS_SATELLITE_COMMUNICATION_ALLOWED, new Pair<>(subId, result));
     }
 
-    private void handleRequestIsSatelliteCommunicationAllowedForCurrentLocation(
-            @NonNull ResultReceiver result) {
-        // To be implemented
+    /**
+     * This API should be used by only CTS tests to override the overlay configs of satellite
+     * access controller.
+     */
+    public boolean setSatelliteAccessControlOverlayConfigs(boolean reset, boolean isAllowed,
+            @Nullable String s2CellFile, long locationFreshDurationNanos,
+            @Nullable List<String> satelliteCountryCodes) {
+        if (!isMockModemAllowed()) {
+            logd("setSatelliteAccessControllerOverlayConfigs: mock modem is not allowed");
+            return false;
+        }
+        logd("setSatelliteAccessControlOverlayConfigs: reset=" + reset
+                + ", isAllowed" + isAllowed + ", s2CellFile=" + s2CellFile
+                + ", locationFreshDurationNanos=" + locationFreshDurationNanos
+                + ", satelliteCountryCodes=" + ((satelliteCountryCodes != null)
+                ? String.join(", ", satelliteCountryCodes) : null));
+        synchronized (mLock) {
+            if (reset) {
+                mIsOverlayConfigOverridden = false;
+                cleanUpCtsResources();
+            } else {
+                mIsOverlayConfigOverridden = true;
+                mOverriddenIsSatelliteAllowAccessControl = isAllowed;
+                if (!TextUtils.isEmpty(s2CellFile)) {
+                    mOverriddenSatelliteS2CellFile = getTestSatelliteS2File(s2CellFile);
+                    if (!mOverriddenSatelliteS2CellFile.exists()) {
+                        logd("The overriding file "
+                                + mOverriddenSatelliteS2CellFile.getAbsolutePath()
+                                + " does not exist");
+                        mOverriddenSatelliteS2CellFile = null;
+                    }
+                } else {
+                    mOverriddenSatelliteS2CellFile = null;
+                }
+                mOverriddenLocationFreshDurationNanos = locationFreshDurationNanos;
+                if (satelliteCountryCodes != null) {
+                    mOverriddenSatelliteCountryCodes = satelliteCountryCodes;
+                } else {
+                    mOverriddenSatelliteCountryCodes = new ArrayList<>();
+                }
+            }
+            cleanupOnDeviceAccessControllerResources();
+            initSatelliteOnDeviceAccessController();
+        }
+        return true;
+    }
+
+    private File getTestSatelliteS2File(String fileName) {
+        logd("getTestSatelliteS2File: fileName=" + fileName);
+        if (TextUtils.equals(fileName, GOOGLE_US_SAN_SAT_S2_FILE_NAME)) {
+            mCtsSatS2FilePath = copyTestSatS2FileToPhoneDirectory(GOOGLE_US_SAN_SAT_S2_FILE_NAME);
+            if (mCtsSatS2FilePath != null) {
+                return mCtsSatS2FilePath.toFile();
+            } else {
+                loge("getTestSatelliteS2File: mCtsSatS2FilePath is null");
+            }
+        }
+        return new File(fileName);
+    }
+
+    @Nullable private static Path copyTestSatS2FileToPhoneDirectory(String sourceFileName) {
+        PhoneGlobals phoneGlobals = PhoneGlobals.getInstance();
+        File ctsFile = phoneGlobals.getDir("cts", Context.MODE_PRIVATE);
+        if (!ctsFile.exists()) {
+            ctsFile.mkdirs();
+        }
+
+        Path targetDir = ctsFile.toPath();
+        Path targetSatS2FilePath = targetDir.resolve(sourceFileName);
+        try {
+            InputStream inputStream = phoneGlobals.getAssets().open(sourceFileName);
+            if (inputStream == null) {
+                loge("copyTestSatS2FileToPhoneDirectory: Resource=" + sourceFileName
+                        + " not found");
+            } else {
+                Files.copy(inputStream, targetSatS2FilePath, StandardCopyOption.REPLACE_EXISTING);
+            }
+        } catch (IOException ex) {
+            loge("copyTestSatS2FileToPhoneDirectory: ex=" + ex);
+        }
+        return targetSatS2FilePath;
+    }
+
+    private void cleanUpCtsResources() {
+        if (mCtsSatS2FilePath != null) {
+            try {
+                Files.delete(mCtsSatS2FilePath);
+            } catch (IOException ex) {
+                loge("cleanUpCtsResources: ex=" + ex);
+            }
+        }
+    }
+
+    @VisibleForTesting(visibility = VisibleForTesting.Visibility.PRIVATE)
+    protected long getElapsedRealtimeNanos() {
+        return SystemClock.elapsedRealtimeNanos();
+    }
+
+    private void loadOverlayConfigs(@NonNull Context context) {
+        mSatelliteCountryCodes = getSatelliteCountryCodesFromOverlayConfig(context);
+        mIsSatelliteAllowAccessControl = getSatelliteAccessAllowFromOverlayConfig(context);
+        String satelliteS2CellFileName = getSatelliteS2CellFileFromOverlayConfig(context);
+        mSatelliteS2CellFile = TextUtils.isEmpty(satelliteS2CellFileName)
+                ? null : new File(satelliteS2CellFileName);
+        if (mSatelliteS2CellFile != null && !mSatelliteS2CellFile.exists()) {
+            loge("The satellite S2 cell file " + satelliteS2CellFileName + " does not exist");
+            mSatelliteS2CellFile = null;
+        }
+        mLocationFreshDurationNanos = getSatelliteLocationFreshDurationFromOverlayConfig(context);
+    }
+
+    private long getLocationFreshDurationNanos() {
+        synchronized (mLock) {
+            if (mIsOverlayConfigOverridden) {
+                return mOverriddenLocationFreshDurationNanos;
+            }
+            return mLocationFreshDurationNanos;
+        }
+    }
+
+    @NonNull private List<String> getSatelliteCountryCodes() {
+        synchronized (mLock) {
+            if (mIsOverlayConfigOverridden) {
+                return mOverriddenSatelliteCountryCodes;
+            }
+            return mSatelliteCountryCodes;
+        }
+    }
+
+    @Nullable private File getSatelliteS2CellFile() {
+        synchronized (mLock) {
+            if (mIsOverlayConfigOverridden) {
+                return mOverriddenSatelliteS2CellFile;
+            }
+            return mSatelliteS2CellFile;
+        }
+    }
+
+    private boolean isSatelliteAllowAccessControl() {
+        synchronized (mLock) {
+            if (mIsOverlayConfigOverridden) {
+                return mOverriddenIsSatelliteAllowAccessControl;
+            }
+            return mIsSatelliteAllowAccessControl;
+        }
+    }
+
+    private void handleCmdIsSatelliteAllowedForCurrentLocation(
+            @NonNull Pair<Integer, ResultReceiver> requestArguments) {
+        synchronized (mLock) {
+            mSatelliteAllowResultReceivers.add(requestArguments.second);
+            if (mSatelliteAllowResultReceivers.size() > 1) {
+                logd("requestIsSatelliteCommunicationAllowedForCurrentLocation is already being "
+                        + "processed");
+                return;
+            }
+            mSatelliteController.requestIsSatelliteCommunicationAllowedForCurrentLocation(
+                    requestArguments.first, mInternalSatelliteAllowResultReceiver);
+        }
+    }
+
+    private void handleWaitForCurrentLocationTimedOutEvent() {
+        logd("Timed out to wait for current location");
+        synchronized (mLock) {
+            if (mLocationRequestCancellationSignal != null) {
+                mLocationRequestCancellationSignal.cancel();
+                mLocationRequestCancellationSignal = null;
+                onCurrentLocationAvailable(null);
+            } else {
+                loge("handleWaitForCurrentLocationTimedOutEvent: "
+                        + "mLocationRequestCancellationSignal is null");
+            }
+        }
+    }
+
+    private void handleSatelliteAllowResultFromSatelliteController(
+            int resultCode, Bundle resultData) {
+        logd("handleSatelliteAllowResultFromSatelliteController: resultCode=" + resultCode);
+        synchronized (mLock) {
+            if (resultCode == SATELLITE_RESULT_SUCCESS) {
+                if (resultData.containsKey(KEY_SATELLITE_COMMUNICATION_ALLOWED)) {
+                    boolean isSatelliteAllowed = resultData.getBoolean(
+                            KEY_SATELLITE_COMMUNICATION_ALLOWED);
+                    if (!isSatelliteAllowed) {
+                        logd("Satellite is not allowed by modem");
+                        sendSatelliteAllowResultToReceivers(resultCode, resultData);
+                    } else {
+                        checkSatelliteAccessRestrictionForCurrentLocation();
+                    }
+                } else {
+                    loge("KEY_SATELLITE_COMMUNICATION_ALLOWED does not exist.");
+                    sendSatelliteAllowResultToReceivers(resultCode, resultData);
+                }
+            } else if (resultCode == SATELLITE_RESULT_REQUEST_NOT_SUPPORTED) {
+                checkSatelliteAccessRestrictionForCurrentLocation();
+            } else {
+                sendSatelliteAllowResultToReceivers(resultCode, resultData);
+            }
+        }
+    }
+
+    private void sendSatelliteAllowResultToReceivers(int resultCode, Bundle resultData) {
+        synchronized (mLock) {
+            for (ResultReceiver resultReceiver : mSatelliteAllowResultReceivers) {
+                resultReceiver.send(resultCode, resultData);
+            }
+            mSatelliteAllowResultReceivers.clear();
+        }
+    }
+
+    /**
+     * Telephony-internal logic to verify if satellite access is restricted at the current location.
+     */
+    private void checkSatelliteAccessRestrictionForCurrentLocation() {
+        synchronized (mLock) {
+            List<String> networkCountryIsoList = mCountryDetector.getCurrentNetworkCountryIso();
+            if (!networkCountryIsoList.isEmpty()) {
+                logd("Use current network country codes=" + String.join(", ",
+                        networkCountryIsoList));
+
+                Bundle bundle = new Bundle();
+                bundle.putBoolean(KEY_SATELLITE_COMMUNICATION_ALLOWED,
+                        isSatelliteAccessAllowedForLocation(networkCountryIsoList));
+                sendSatelliteAllowResultToReceivers(SATELLITE_RESULT_SUCCESS, bundle);
+            } else {
+                if (shouldUseOnDeviceAccessController()) {
+                    // This will be an asynchronous check when it needs to wait for the current
+                    // location from location service
+                    checkSatelliteAccessRestrictionUsingOnDeviceData();
+                } else {
+                    // This is always a synchronous check
+                    checkSatelliteAccessRestrictionUsingCachedCountryCodes();
+                }
+            }
+        }
+    }
+
+    /**
+     * This function synchronously checks if satellite is allowed at current location using cached
+     * country codes.
+     */
+    private void checkSatelliteAccessRestrictionUsingCachedCountryCodes() {
+        Pair<String, Long> locationCountryCodeInfo =
+                mCountryDetector.getCachedLocationCountryIsoInfo();
+        Map<String, Long> networkCountryCodeInfoMap =
+                mCountryDetector.getCachedNetworkCountryIsoInfo();
+        List<String> countryCodeList;
+
+        // Check if the cached location country code's timestamp is newer than all cached network
+        // country codes
+        if (!TextUtils.isEmpty(locationCountryCodeInfo.first) && isGreaterThanAll(
+                locationCountryCodeInfo.second, networkCountryCodeInfoMap.values())) {
+            // Use cached location country code
+            countryCodeList = Arrays.asList(locationCountryCodeInfo.first);
+        } else {
+            // Use cached network country codes
+            countryCodeList = networkCountryCodeInfoMap.keySet().stream().toList();
+        }
+        logd("Use cached country codes=" + String.join(", ", countryCodeList));
+
+        Bundle bundle = new Bundle();
+        bundle.putBoolean(KEY_SATELLITE_COMMUNICATION_ALLOWED,
+                isSatelliteAccessAllowedForLocation(countryCodeList));
+        sendSatelliteAllowResultToReceivers(SATELLITE_RESULT_SUCCESS, bundle);
+    }
+
+    /**
+     * This function asynchronously checks if satellite is allowed at the current location using
+     * on-device data. Asynchronous check happens when it needs to wait for the current location
+     * from location service.
+     */
+    private void checkSatelliteAccessRestrictionUsingOnDeviceData() {
+        synchronized (mLock) {
+            logd("Use on-device data");
+            if (mFreshLastKnownLocation != null) {
+                checkSatelliteAccessRestrictionForLocation(mFreshLastKnownLocation);
+                mFreshLastKnownLocation = null;
+            } else {
+                Location freshLastKnownLocation = getFreshLastKnownLocation();
+                if (freshLastKnownLocation != null) {
+                    checkSatelliteAccessRestrictionForLocation(freshLastKnownLocation);
+                } else {
+                    queryCurrentLocation();
+                }
+            }
+        }
+    }
+
+    private void queryCurrentLocation() {
+        synchronized (mLock) {
+            if (mLocationRequestCancellationSignal != null) {
+                logd("Request for current location was already sent to LocationManager");
+                return;
+            }
+            mLocationRequestCancellationSignal = new CancellationSignal();
+            mLocationManager.getCurrentLocation(LocationManager.GPS_PROVIDER,
+                    new LocationRequest.Builder(0)
+                            .setQuality(LocationRequest.QUALITY_HIGH_ACCURACY)
+                            .setLocationSettingsIgnored(true)
+                            .build(),
+                    mLocationRequestCancellationSignal, this::post,
+                    this::onCurrentLocationAvailable);
+            startWaitForCurrentLocationTimer();
+        }
+    }
+
+    private void onCurrentLocationAvailable(@Nullable Location location) {
+        logd("onCurrentLocationAvailable " + (location != null));
+        synchronized (mLock) {
+            stopWaitForCurrentLocationTimer();
+            mLocationRequestCancellationSignal = null;
+            if (location != null) {
+                checkSatelliteAccessRestrictionForLocation(location);
+            } else {
+                checkSatelliteAccessRestrictionUsingCachedCountryCodes();
+            }
+        }
+    }
+
+    private void checkSatelliteAccessRestrictionForLocation(@NonNull Location location) {
+        synchronized (mLock) {
+            try {
+                SatelliteOnDeviceAccessController.LocationToken locationToken =
+                        SatelliteOnDeviceAccessController.createLocationTokenForLatLng(
+                                location.getLatitude(),
+                                location.getLongitude(), mS2Level);
+                boolean satelliteAllowed;
+                if (mCachedAccessRestrictionMap.containsKey(locationToken)) {
+                    satelliteAllowed = mCachedAccessRestrictionMap.get(locationToken);
+                } else {
+                    if (!initSatelliteOnDeviceAccessController()) {
+                        loge("Failed to init SatelliteOnDeviceAccessController");
+                        checkSatelliteAccessRestrictionUsingCachedCountryCodes();
+                        return;
+                    }
+                    satelliteAllowed = mSatelliteOnDeviceAccessController
+                            .isSatCommunicationAllowedAtLocation(locationToken);
+                    updateCachedAccessRestrictionMap(locationToken, satelliteAllowed);
+                }
+                Bundle bundle = new Bundle();
+                bundle.putBoolean(KEY_SATELLITE_COMMUNICATION_ALLOWED, satelliteAllowed);
+                sendSatelliteAllowResultToReceivers(SATELLITE_RESULT_SUCCESS, bundle);
+            } catch (Exception ex) {
+                loge("checkSatelliteAccessRestrictionForLocation: ex=" + ex);
+                reportAnomaly(UUID_ON_DEVICE_LOOKUP_EXCEPTION,
+                        "On-device satellite lookup exception");
+                checkSatelliteAccessRestrictionUsingCachedCountryCodes();
+            }
+        }
+    }
+
+    private void updateCachedAccessRestrictionMap(@NonNull
+            SatelliteOnDeviceAccessController.LocationToken locationToken,
+            boolean satelliteAllowed) {
+        synchronized (mLock) {
+            mCachedAccessRestrictionMap.put(locationToken, satelliteAllowed);
+        }
+    }
+
+    private boolean isGreaterThanAll(
+            long comparedItem, @NonNull Collection<Long> itemCollection) {
+        for (long item : itemCollection) {
+            if (comparedItem <= item) return false;
+        }
+        return true;
+    }
+
+    private boolean isSatelliteAccessAllowedForLocation(
+            @NonNull List<String> networkCountryIsoList) {
+        if (isSatelliteAllowAccessControl()) {
+            // The current country is unidentified, we're uncertain and thus returning false
+            if (networkCountryIsoList.isEmpty()) {
+                return false;
+            }
+
+            // In case of allowed list, satellite is allowed if all country codes are be in the
+            // allowed list
+            return getSatelliteCountryCodes().containsAll(networkCountryIsoList);
+        } else {
+            // No country is barred, thus returning true
+            if (getSatelliteCountryCodes().isEmpty()) {
+                return true;
+            }
+
+            // The current country is unidentified, we're uncertain and thus returning false
+            if (networkCountryIsoList.isEmpty()) {
+                return false;
+            }
+
+            // In case of disallowed list, if any country code is in the list, satellite will be
+            // disallowed
+            for (String countryCode : networkCountryIsoList) {
+                if (getSatelliteCountryCodes().contains(countryCode)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+
+    private boolean shouldUseOnDeviceAccessController() {
+        if (getSatelliteS2CellFile() == null) {
+            return false;
+        }
+
+        if (isInEmergency() || mLocationManager.isLocationEnabled()) {
+            return true;
+        }
+
+        Location freshLastKnownLocation = getFreshLastKnownLocation();
+        if (freshLastKnownLocation != null) {
+            synchronized (mLock) {
+                mFreshLastKnownLocation = freshLastKnownLocation;
+            }
+            return true;
+        } else {
+            synchronized (mLock) {
+                mFreshLastKnownLocation = null;
+            }
+        }
+        return false;
+    }
+
+    @Nullable private Location getFreshLastKnownLocation() {
+        Location lastKnownLocation = getLastKnownLocation();
+        if (lastKnownLocation != null) {
+            long lastKnownLocationAge =
+                    getElapsedRealtimeNanos() - lastKnownLocation.getElapsedRealtimeNanos();
+            if (lastKnownLocationAge <= getLocationFreshDurationNanos()) {
+                return lastKnownLocation;
+            }
+        }
+        return null;
+    }
+
+    private boolean isInEmergency() {
+        // Check if emergency call is ongoing
+        if (mTelecomManager.isInEmergencyCall()) {
+            return true;
+        }
+        // Check if the device is in emergency callback mode
+        for (Phone phone : PhoneFactory.getPhones()) {
+            if (phone.isInEcm()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Nullable
+    private Location getLastKnownLocation() {
+        Location result = null;
+        for (String provider : mLocationManager.getProviders(true)) {
+            Location location = mLocationManager.getLastKnownLocation(provider);
+            if (location != null && (result == null
+                    || result.getElapsedRealtimeNanos() < location.getElapsedRealtimeNanos())) {
+                result = location;
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @return {@code true} if successfully initialize the {@link SatelliteOnDeviceAccessController}
+     * instance, {@code false} otherwise.
+     * @throws IllegalStateException in case of getting any exception in creating the
+     * {@link SatelliteOnDeviceAccessController} instance and the device is using a user build.
+     */
+    private boolean initSatelliteOnDeviceAccessController() throws IllegalStateException {
+        synchronized (mLock) {
+            if (getSatelliteS2CellFile() == null) return false;
+
+            // mSatelliteOnDeviceAccessController was already initialized successfully
+            if (mSatelliteOnDeviceAccessController != null) {
+                restartKeepOnDeviceAccessControllerResourcesTimer();
+                return true;
+            }
+
+            try {
+                mSatelliteOnDeviceAccessController =
+                        SatelliteOnDeviceAccessController.create(getSatelliteS2CellFile());
+                restartKeepOnDeviceAccessControllerResourcesTimer();
+                mS2Level = mSatelliteOnDeviceAccessController.getS2Level();
+                logd("mS2Level=" + mS2Level);
+            } catch (Exception ex) {
+                loge("Got exception in creating an instance of SatelliteOnDeviceAccessController,"
+                        + " ex=" + ex + ", sat s2 file="
+                        + getSatelliteS2CellFile().getAbsolutePath());
+                reportAnomaly(UUID_CREATE_ON_DEVICE_ACCESS_CONTROLLER_EXCEPTION,
+                        "Exception in creating on-device satellite access controller");
+                mSatelliteOnDeviceAccessController = null;
+                if (!mIsOverlayConfigOverridden) {
+                    mSatelliteS2CellFile = null;
+                }
+                return false;
+            }
+            return true;
+        }
+    }
+
+    private void cleanupOnDeviceAccessControllerResources() {
+        synchronized (mLock) {
+            logd("cleanupOnDeviceAccessControllerResources="
+                    + (mSatelliteOnDeviceAccessController != null));
+            if (mSatelliteOnDeviceAccessController != null) {
+                try {
+                    mSatelliteOnDeviceAccessController.close();
+                } catch (Exception ex) {
+                    loge("cleanupOnDeviceAccessControllerResources: ex=" + ex);
+                }
+                mSatelliteOnDeviceAccessController = null;
+                stopKeepOnDeviceAccessControllerResourcesTimer();
+            }
+        }
+    }
+
+    private static boolean getSatelliteAccessAllowFromOverlayConfig(@NonNull Context context) {
+        Boolean accessAllowed = null;
+        try {
+            accessAllowed = context.getResources().getBoolean(
+                    com.android.internal.R.bool.config_oem_enabled_satellite_access_allow);
+        } catch (Resources.NotFoundException ex) {
+            loge("getSatelliteAccessAllowFromOverlayConfig: got ex=" + ex);
+        }
+        if (accessAllowed == null && isMockModemAllowed()) {
+            logd("getSatelliteAccessAllowFromOverlayConfig: Read "
+                    + "config_oem_enabled_satellite_access_allow from device config");
+            accessAllowed = DeviceConfig.getBoolean(DeviceConfig.NAMESPACE_TELEPHONY,
+                    "config_oem_enabled_satellite_access_allow", DEFAULT_SATELLITE_ACCESS_ALLOW);
+        }
+        if (accessAllowed == null) {
+            logd("Use default satellite access allow=true control");
+            accessAllowed = true;
+        }
+        return accessAllowed;
+    }
+
+    @Nullable
+    private static String getSatelliteS2CellFileFromOverlayConfig(@NonNull Context context) {
+        String s2CellFile = null;
+        try {
+            s2CellFile = context.getResources().getString(
+                    com.android.internal.R.string.config_oem_enabled_satellite_s2cell_file);
+        } catch (Resources.NotFoundException ex) {
+            loge("getSatelliteS2CellFileFromOverlayConfig: got ex=" + ex);
+        }
+        if (TextUtils.isEmpty(s2CellFile) && isMockModemAllowed()) {
+            logd("getSatelliteS2CellFileFromOverlayConfig: Read "
+                    + "config_oem_enabled_satellite_s2cell_file from device config");
+            s2CellFile = DeviceConfig.getString(DeviceConfig.NAMESPACE_TELEPHONY,
+                    "config_oem_enabled_satellite_s2cell_file", null);
+        }
+        logd("s2CellFile=" + s2CellFile);
+        return s2CellFile;
+    }
+
+    @NonNull
+    private static List<String> getSatelliteCountryCodesFromOverlayConfig(
+            @NonNull Context context) {
+        String[] countryCodes = readStringArrayFromOverlayConfig(context,
+                com.android.internal.R.array.config_oem_enabled_satellite_country_codes);
+        if (countryCodes.length == 0 && isMockModemAllowed()) {
+            logd("getSatelliteCountryCodesFromOverlayConfig: Read "
+                    + "config_oem_enabled_satellite_country_codes from device config");
+            String countryCodesStr = DeviceConfig.getString(DeviceConfig.NAMESPACE_TELEPHONY,
+                    "config_oem_enabled_satellite_country_codes", "");
+            countryCodes = countryCodesStr.split(",");
+        }
+        return Arrays.stream(countryCodes)
+                .map(x -> x.toUpperCase(Locale.US))
+                .collect(Collectors.toList());
+    }
+
+    @NonNull
+    private static String[] readStringArrayFromOverlayConfig(
+            @NonNull Context context, @ArrayRes int id) {
+        String[] strArray = null;
+        try {
+            strArray = context.getResources().getStringArray(id);
+        } catch (Resources.NotFoundException ex) {
+            loge("readStringArrayFromOverlayConfig: id= " + id + ", ex=" + ex);
+        }
+        if (strArray == null) {
+            strArray = new String[0];
+        }
+        return strArray;
+    }
+
+    private static long getSatelliteLocationFreshDurationFromOverlayConfig(
+            @NonNull Context context) {
+        Integer freshDuration = null;
+        try {
+            freshDuration = context.getResources().getInteger(com.android.internal.R.integer
+                    .config_oem_enabled_satellite_location_fresh_duration);
+        } catch (Resources.NotFoundException ex) {
+            loge("getSatelliteLocationFreshDurationFromOverlayConfig: got ex=" + ex);
+        }
+        if (freshDuration == null && isMockModemAllowed()) {
+            logd("getSatelliteLocationFreshDurationFromOverlayConfig: Read "
+                    + "config_oem_enabled_satellite_location_fresh_duration from device config");
+            freshDuration = DeviceConfig.getInt(DeviceConfig.NAMESPACE_TELEPHONY,
+                    "config_oem_enabled_satellite_location_fresh_duration",
+                    DEFAULT_LOCATION_FRESH_DURATION_SECONDS);
+        }
+        if (freshDuration == null) {
+            logd("Use default satellite location fresh duration="
+                    + DEFAULT_LOCATION_FRESH_DURATION_SECONDS);
+            freshDuration = DEFAULT_LOCATION_FRESH_DURATION_SECONDS;
+        }
+        return TimeUnit.SECONDS.toNanos(freshDuration);
+    }
+
+    private void startWaitForCurrentLocationTimer() {
+        synchronized (mLock) {
+            if (hasMessages(EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT)) {
+                logw("WaitForCurrentLocationTimer is already started");
+                removeMessages(EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT);
+            }
+            sendEmptyMessageDelayed(EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT,
+                    WAIT_FOR_CURRENT_LOCATION_TIMEOUT_MILLIS);
+        }
+    }
+
+    private void stopWaitForCurrentLocationTimer() {
+        synchronized (mLock) {
+            removeMessages(EVENT_WAIT_FOR_CURRENT_LOCATION_TIMEOUT);
+        }
+    }
+
+    private void restartKeepOnDeviceAccessControllerResourcesTimer() {
+        synchronized (mLock) {
+            if (hasMessages(EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT)) {
+                logd("KeepOnDeviceAccessControllerResourcesTimer is already started. "
+                        + "Restarting it...");
+                removeMessages(EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT);
+            }
+            sendEmptyMessageDelayed(EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT,
+                    KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT_MILLIS);
+        }
+    }
+
+    private void stopKeepOnDeviceAccessControllerResourcesTimer() {
+        synchronized (mLock) {
+            removeMessages(EVENT_KEEP_ON_DEVICE_ACCESS_CONTROLLER_RESOURCES_TIMEOUT);
+        }
+    }
+
+    private void reportAnomaly(@NonNull String uuid, @NonNull String log) {
+        loge(log);
+        AnomalyReporter.reportAnomaly(UUID.fromString(uuid), log);
+    }
+
+    private static boolean isMockModemAllowed() {
+        return (DEBUG || SystemProperties.getBoolean(ALLOW_MOCK_MODEM_PROPERTY, false)
+                || SystemProperties.getBoolean(BOOT_ALLOW_MOCK_MODEM_PROPERTY, false));
     }
 
     /**
diff --git a/src/com/android/phone/satellite/accesscontrol/SatelliteOnDeviceAccessController.java b/src/com/android/phone/satellite/accesscontrol/SatelliteOnDeviceAccessController.java
index 9292f33..520699f 100644
--- a/src/com/android/phone/satellite/accesscontrol/SatelliteOnDeviceAccessController.java
+++ b/src/com/android/phone/satellite/accesscontrol/SatelliteOnDeviceAccessController.java
@@ -45,11 +45,12 @@
 
     /**
      * Returns a token for a given location. See {@link LocationToken} for details.
-     *
-     * @throws IOException in the unlikely event of errors when reading the underlying file
      */
-    public abstract LocationToken createLocationTokenForLatLng(double latDegrees, double lngDegrees)
-            throws IOException;
+    public static LocationToken createLocationTokenForLatLng(double latDegrees, double lngDegrees,
+            int s2Level) {
+        return S2RangeSatelliteOnDeviceAccessController
+                .createLocationTokenForLatLng(latDegrees, lngDegrees, s2Level);
+    }
 
     /**
      * Returns {@code true} if the satellite communication is allowed at the provided location,
@@ -61,6 +62,11 @@
             throws IOException;
 
     /**
+     * Returns the S2 level of the file.
+     */
+    public abstract int getS2Level();
+
+    /**
      * A class that represents an area with the same value. Two locations with tokens that
      * {@link #equals(Object) equal each other} will definitely return the same value.
      *