diff --git a/core/java/android/bluetooth/BluetoothAdapter.java b/core/java/android/bluetooth/BluetoothAdapter.java
index be4e207..6aabe18 100644
--- a/core/java/android/bluetooth/BluetoothAdapter.java
+++ b/core/java/android/bluetooth/BluetoothAdapter.java
@@ -676,6 +676,10 @@
         if (!getLeAccess()) {
             return null;
         }
+        if (!isMultipleAdvertisementSupported()) {
+            Log.e(TAG, "Bluetooth LE advertising not supported");
+            return null;
+        }
         synchronized (mLock) {
             if (sBluetoothLeAdvertiser == null) {
                 sBluetoothLeAdvertiser = new BluetoothLeAdvertiser(mManagerService);
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index ca3f5e9..517995e 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -8706,6 +8706,12 @@
         public static final String BLE_SCAN_LOW_LATENCY_INTERVAL_MS =
                 "ble_scan_low_latency_interval_ms";
 
+        /**
+         * The mode that BLE scanning clients will be moved to when in the background.
+         * @hide
+         */
+        public static final String BLE_SCAN_BACKGROUND_MODE = "ble_scan_background_mode";
+
        /**
         * Used to save the Wifi_ON state prior to tethering.
         * This state will be checked to restore Wifi after
diff --git a/core/res/res/values/strings.xml b/core/res/res/values/strings.xml
index 503d264..e0ae966 100644
--- a/core/res/res/values/strings.xml
+++ b/core/res/res/values/strings.xml
@@ -150,13 +150,13 @@
     <string name="RestrictedStateContent">Temporarily turned off by your carrier</string>
 
     <!-- Displayed to tell the user that they should switch their network preference. -->
-    <string name="NetworkPreferenceSwitchTitle">Can\u2019t reach network</string>
+    <string name="NetworkPreferenceSwitchTitle">Can\u2019t reach mobile network</string>
     <!-- Displayed to tell the user that they should switch their network preference. -->
-    <string name="NetworkPreferenceSwitchSummary">To improve reception, try changing the type selected at Settings &gt; Network &amp; Internet &gt; Mobile networks &gt; Preferred network type."</string>
+    <string name="NetworkPreferenceSwitchSummary">Try changing preferred network. Tap to change.</string>
     <!-- Displayed to tell the user that emergency calls might not be available. -->
-    <string name="EmergencyCallWarningTitle">Wi\u2011Fi calling is active</string>
+    <string name="EmergencyCallWarningTitle">Emergency calling unavailable</string>
     <!-- Displayed to tell the user that emergency calls might not be available. -->
-    <string name="EmergencyCallWarningSummary">Emergency calls require a mobile network.</string>
+    <string name="EmergencyCallWarningSummary">Can\u2019t make emergency calls over Wi\u2011Fi</string>
 
     <!-- Telephony notification channel name for a channel containing network alert notifications. -->
     <string name="notification_channel_network_alert">Alerts</string>
@@ -4682,11 +4682,11 @@
     <!-- Primary ETWS (Earthquake and Tsunami Warning System) default message for others -->
     <string name="etws_primary_default_message_others"></string>
 
-    <!-- Title of notification when UE fails to register network with MM reject cause code. -->
-    <string name="mmcc_authentication_reject">SIM not allowed</string>
-    <string name="mmcc_imsi_unknown_in_hlr">SIM not provisioned</string>
-    <string name="mmcc_illegal_ms">SIM not allowed</string>
-    <string name="mmcc_illegal_me">Phone not allowed</string>
+    <!-- Title of notification when UE fails CS registration network with MM reject cause code from network. -->
+    <string name="mmcc_authentication_reject">SIM not allowed for voice</string>
+    <string name="mmcc_imsi_unknown_in_hlr">SIM not provisioned for voice</string>
+    <string name="mmcc_illegal_ms">SIM not allowed for voice</string>
+    <string name="mmcc_illegal_me">Phone not allowed for voice</string>
 
     <!-- Popup window default title to be read by a screen reader-->
     <string name="popup_window_default_title">Popup Window</string>
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index 757a70c..16c0b8c 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -117,6 +117,7 @@
                     Settings.Global.BLE_SCAN_BALANCED_INTERVAL_MS,
                     Settings.Global.BLE_SCAN_LOW_LATENCY_WINDOW_MS,
                     Settings.Global.BLE_SCAN_LOW_LATENCY_INTERVAL_MS,
+                    Settings.Global.BLE_SCAN_BACKGROUND_MODE,
                     Settings.Global.BLUETOOTH_A2DP_SINK_PRIORITY_PREFIX,
                     Settings.Global.BLUETOOTH_A2DP_SRC_PRIORITY_PREFIX,
                     Settings.Global.BLUETOOTH_A2DP_SUPPORTS_OPTIONAL_CODECS_PREFIX,
diff --git a/services/core/java/com/android/server/TelephonyRegistry.java b/services/core/java/com/android/server/TelephonyRegistry.java
index 62e82a0..3896871 100644
--- a/services/core/java/com/android/server/TelephonyRegistry.java
+++ b/services/core/java/com/android/server/TelephonyRegistry.java
@@ -65,7 +65,6 @@
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.NoSuchElementException;
 
@@ -164,14 +163,9 @@
 
     private int[] mDataActivity;
 
+    // Connection state of default APN type data (i.e. internet) of phones
     private int[] mDataConnectionState;
 
-    private ArrayList<String>[] mConnectedApns;
-
-    private LinkProperties[] mDataConnectionLinkProperties;
-
-    private NetworkCapabilities[] mDataConnectionNetworkCapabilities;
-
     private Bundle[] mCellLocation;
 
     private int[] mDataConnectionNetworkType;
@@ -323,9 +317,8 @@
         mBatteryStats = BatteryStatsService.getService();
 
         int numPhones = TelephonyManager.getDefault().getPhoneCount();
-        if (DBG) log("TelephonyRegistor: ctor numPhones=" + numPhones);
+        if (DBG) log("TelephonyRegistry: ctor numPhones=" + numPhones);
         mNumPhones = numPhones;
-        mConnectedApns = new ArrayList[numPhones];
         mCallState = new int[numPhones];
         mDataActivity = new int[numPhones];
         mDataConnectionState = new int[numPhones];
@@ -339,8 +332,6 @@
         mMessageWaiting = new boolean[numPhones];
         mCallForwarding = new boolean[numPhones];
         mCellLocation = new Bundle[numPhones];
-        mDataConnectionLinkProperties = new LinkProperties[numPhones];
-        mDataConnectionNetworkCapabilities = new NetworkCapabilities[numPhones];
         mCellInfo = new ArrayList<List<CellInfo>>();
         mPhysicalChannelConfigs = new ArrayList<List<PhysicalChannelConfig>>();
         for (int i = 0; i < numPhones; i++) {
@@ -358,7 +349,6 @@
             mCellLocation[i] = new Bundle();
             mCellInfo.add(i, null);
             mPhysicalChannelConfigs.add(i, null);
-            mConnectedApns[i] = new ArrayList<String>();
         }
 
         // Note that location can be null for non-phone builds like
@@ -1219,36 +1209,12 @@
         int phoneId = SubscriptionManager.getPhoneId(subId);
         synchronized (mRecords) {
             if (validatePhoneId(phoneId)) {
-                boolean modified = false;
-                if (state == TelephonyManager.DATA_CONNECTED) {
-                    if (!mConnectedApns[phoneId].contains(apnType)) {
-                        mConnectedApns[phoneId].add(apnType);
-                        if (mDataConnectionState[phoneId] != state) {
-                            mDataConnectionState[phoneId] = state;
-                            modified = true;
-                        }
-                    }
-                } else {
-                    if (mConnectedApns[phoneId].remove(apnType)) {
-                        if (mConnectedApns[phoneId].isEmpty()) {
-                            mDataConnectionState[phoneId] = state;
-                            modified = true;
-                        } else {
-                            // leave mDataConnectionState as is and
-                            // send out the new status for the APN in question.
-                        }
-                    }
-                }
-                mDataConnectionLinkProperties[phoneId] = linkProperties;
-                mDataConnectionNetworkCapabilities[phoneId] = networkCapabilities;
-                if (mDataConnectionNetworkType[phoneId] != networkType) {
-                    mDataConnectionNetworkType[phoneId] = networkType;
-                    // need to tell registered listeners about the new network type
-                    modified = true;
-                }
-                if (modified) {
-                    String str = "onDataConnectionStateChanged(" + mDataConnectionState[phoneId]
-                            + ", " + mDataConnectionNetworkType[phoneId] + ")";
+                // We only call the callback when the change is for default APN type.
+                if (PhoneConstants.APN_TYPE_DEFAULT.equals(apnType)
+                        && (mDataConnectionState[phoneId] != state
+                        || mDataConnectionNetworkType[phoneId] != networkType)) {
+                    String str = "onDataConnectionStateChanged(" + state
+                            + ", " + networkType + ")";
                     log(str);
                     mLocalLog.log(str);
                     for (Record r : mRecords) {
@@ -1259,15 +1225,16 @@
                                 if (DBG) {
                                     log("Notify data connection state changed on sub: " + subId);
                                 }
-                                r.callback.onDataConnectionStateChanged(
-                                        mDataConnectionState[phoneId],
-                                        mDataConnectionNetworkType[phoneId]);
+                                r.callback.onDataConnectionStateChanged(state, networkType);
                             } catch (RemoteException ex) {
                                 mRemoveList.add(r.binder);
                             }
                         }
                     }
                     handleRemoveListLocked();
+
+                    mDataConnectionState[phoneId] = state;
+                    mDataConnectionNetworkType[phoneId] = networkType;
                 }
                 mPreciseDataConnectionState = new PreciseDataConnectionState(state, networkType,
                         apnType, apn, reason, linkProperties, "");
@@ -1503,14 +1470,10 @@
                 pw.println("mCallForwarding=" + mCallForwarding[i]);
                 pw.println("mDataActivity=" + mDataActivity[i]);
                 pw.println("mDataConnectionState=" + mDataConnectionState[i]);
-                pw.println("mDataConnectionLinkProperties=" + mDataConnectionLinkProperties[i]);
-                pw.println("mDataConnectionNetworkCapabilities=" +
-                        mDataConnectionNetworkCapabilities[i]);
                 pw.println("mCellLocation=" + mCellLocation[i]);
                 pw.println("mCellInfo=" + mCellInfo.get(i));
                 pw.decreaseIndent();
             }
-            pw.println("mConnectedApns=" + Arrays.toString(mConnectedApns));
             pw.println("mPreciseDataConnectionState=" + mPreciseDataConnectionState);
             pw.println("mPreciseCallState=" + mPreciseCallState);
             pw.println("mCarrierNetworkChangeState=" + mCarrierNetworkChangeState);
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 37db963..0b7fa64 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -5425,7 +5425,10 @@
      * app has carrier privileges (see {@link #hasCarrierPrivileges}).
      *
      * @param request Contains all the RAT with bands/channels that need to be scanned.
-     * @param executor The executor through which the callback should be invoked.
+     * @param executor The executor through which the callback should be invoked. Since the scan
+     *        request may trigger multiple callbacks and they must be invoked in the same order as
+     *        they are received by the platform, the user should provide an executor which executes
+     *        tasks one at a time in serial order. For example AsyncTask.SERIAL_EXECUTOR.
      * @param callback Returns network scan results or errors.
      * @return A NetworkScan obj which contains a callback which can be used to stop the scan.
      */
@@ -5451,7 +5454,7 @@
     @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE)
     public NetworkScan requestNetworkScan(
         NetworkScanRequest request, TelephonyScanManager.NetworkScanCallback callback) {
-        return requestNetworkScan(request, AsyncTask.THREAD_POOL_EXECUTOR, callback);
+        return requestNetworkScan(request, AsyncTask.SERIAL_EXECUTOR, callback);
     }
 
     /**
diff --git a/telephony/java/android/telephony/TelephonyScanManager.java b/telephony/java/android/telephony/TelephonyScanManager.java
index 99e2db8..96ff332 100644
--- a/telephony/java/android/telephony/TelephonyScanManager.java
+++ b/telephony/java/android/telephony/TelephonyScanManager.java
@@ -137,8 +137,10 @@
                             for (int i = 0; i < parcelables.length; i++) {
                                 ci[i] = (CellInfo) parcelables[i];
                             }
-                            executor.execute(() ->
-                                    callback.onResults((List<CellInfo>) Arrays.asList(ci)));
+                            executor.execute(() ->{
+                                Rlog.d(TAG, "onResults: " + ci.toString());
+                                callback.onResults((List<CellInfo>) Arrays.asList(ci));
+                            });
                         } catch (Exception e) {
                             Rlog.e(TAG, "Exception in networkscan callback onResults", e);
                         }
@@ -146,14 +148,20 @@
                     case CALLBACK_SCAN_ERROR:
                         try {
                             final int errorCode = message.arg1;
-                            executor.execute(() -> callback.onError(errorCode));
+                            executor.execute(() -> {
+                                Rlog.d(TAG, "onError: " + errorCode);
+                                callback.onError(errorCode);
+                            });
                         } catch (Exception e) {
                             Rlog.e(TAG, "Exception in networkscan callback onError", e);
                         }
                         break;
                     case CALLBACK_SCAN_COMPLETE:
                         try {
-                            executor.execute(() -> callback.onComplete());
+                            executor.execute(() -> {
+                                Rlog.d(TAG, "onComplete");
+                                callback.onComplete();
+                            });
                             mScanInfo.remove(message.arg2);
                         } catch (Exception e) {
                             Rlog.e(TAG, "Exception in networkscan callback onComplete", e);