diff --git a/api/system-current.txt b/api/system-current.txt
index ecc9412..bb64d91 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -5654,14 +5654,6 @@
 
 }
 
-package android.os.telephony {
-
-  public class TelephonyRegistryManager {
-    method public void notifyCarrierNetworkChange(boolean);
-  }
-
-}
-
 package android.permission {
 
   public final class PermissionControllerManager {
@@ -8334,6 +8326,14 @@
     field public static final int SRVCC_STATE_HANDOVER_STARTED = 0; // 0x0
   }
 
+  public class TelephonyRegistryManager {
+    method public void addOnOpportunisticSubscriptionsChangedListener(@NonNull android.telephony.SubscriptionManager.OnOpportunisticSubscriptionsChangedListener, @NonNull java.util.concurrent.Executor);
+    method public void addOnSubscriptionsChangedListener(@NonNull android.telephony.SubscriptionManager.OnSubscriptionsChangedListener, @NonNull java.util.concurrent.Executor);
+    method public void notifyCarrierNetworkChange(boolean);
+    method public void removeOnOpportunisticSubscriptionsChangedListener(@NonNull android.telephony.SubscriptionManager.OnOpportunisticSubscriptionsChangedListener);
+    method public void removeOnSubscriptionsChangedListener(@NonNull android.telephony.SubscriptionManager.OnSubscriptionsChangedListener);
+  }
+
   public final class UiccAccessRule implements android.os.Parcelable {
     ctor public UiccAccessRule(byte[], @Nullable String, long);
     method public int describeContents();
diff --git a/core/java/android/app/SystemServiceRegistry.java b/core/java/android/app/SystemServiceRegistry.java
index 646f0dc..8926fb9 100644
--- a/core/java/android/app/SystemServiceRegistry.java
+++ b/core/java/android/app/SystemServiceRegistry.java
@@ -157,7 +157,7 @@
 import android.os.image.DynamicSystemManager;
 import android.os.image.IDynamicSystemService;
 import android.os.storage.StorageManager;
-import android.os.telephony.TelephonyRegistryManager;
+import android.telephony.TelephonyRegistryManager;
 import android.permission.PermissionControllerManager;
 import android.permission.PermissionManager;
 import android.print.IPrintManager;
@@ -613,7 +613,7 @@
             new CachedServiceFetcher<TelephonyRegistryManager>() {
                 @Override
                 public TelephonyRegistryManager createService(ContextImpl ctx) {
-                    return new TelephonyRegistryManager();
+                    return new TelephonyRegistryManager(ctx);
                 }});
 
         registerService(Context.TELEPHONY_SUBSCRIPTION_SERVICE, SubscriptionManager.class,
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index a8c1216..bf417ea 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -63,6 +63,7 @@
 import android.os.UserManager;
 import android.os.storage.StorageManager;
 import android.provider.MediaStore;
+import android.telephony.TelephonyRegistryManager;
 import android.util.AttributeSet;
 import android.view.Display;
 import android.view.DisplayAdjustments;
@@ -4747,7 +4748,7 @@
 
     /**
      * Use with {@link #getSystemService(String)} to retrieve an
-     * {@link android.os.telephony.TelephonyRegistryManager}.
+     * {@link TelephonyRegistryManager}.
      * @hide
      */
     @SystemApi
diff --git a/core/java/android/service/carrier/CarrierService.java b/core/java/android/service/carrier/CarrierService.java
index 9184d6d..eefc1b7 100644
--- a/core/java/android/service/carrier/CarrierService.java
+++ b/core/java/android/service/carrier/CarrierService.java
@@ -22,7 +22,7 @@
 import android.os.IBinder;
 import android.os.PersistableBundle;
 import android.os.ResultReceiver;
-import android.os.telephony.TelephonyRegistryManager;
+import android.telephony.TelephonyRegistryManager;
 import android.util.Log;
 
 /**
diff --git a/telephony/java/android/telephony/PhoneStateListener.java b/core/java/android/telephony/PhoneStateListener.java
similarity index 99%
rename from telephony/java/android/telephony/PhoneStateListener.java
rename to core/java/android/telephony/PhoneStateListener.java
index e5bfb4d..2af827e 100644
--- a/telephony/java/android/telephony/PhoneStateListener.java
+++ b/core/java/android/telephony/PhoneStateListener.java
@@ -35,8 +35,8 @@
 import android.telephony.emergency.EmergencyNumber;
 import android.telephony.ims.ImsReasonInfo;
 
-import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.telephony.IPhoneStateListener;
+import com.android.internal.annotations.VisibleForTesting;
 
 import dalvik.system.VMRuntime;
 
diff --git a/core/java/android/os/telephony/TelephonyRegistryManager.java b/core/java/android/telephony/TelephonyRegistryManager.java
similarity index 75%
rename from core/java/android/os/telephony/TelephonyRegistryManager.java
rename to core/java/android/telephony/TelephonyRegistryManager.java
index b674099..c1af81c 100644
--- a/core/java/android/os/telephony/TelephonyRegistryManager.java
+++ b/core/java/android/telephony/TelephonyRegistryManager.java
@@ -13,12 +13,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.os.telephony;
+package android.telephony;
 
+import android.annotation.CallbackExecutor;
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
+import android.content.Context;
 import android.net.LinkProperties;
 import android.net.NetworkCapabilities;
+import android.os.Binder;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.HandlerExecutor;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.telephony.Annotation;
@@ -41,8 +47,15 @@
 import android.telephony.TelephonyManager;
 import android.telephony.data.ApnSetting;
 import android.telephony.ims.ImsReasonInfo;
+import android.util.Log;
+
 import com.android.internal.telephony.ITelephonyRegistry;
+import com.android.internal.telephony.IOnSubscriptionsChangedListener;
+
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executor;
 
 /**
  * A centralized place to notify telephony related status changes, e.g, {@link ServiceState} update
@@ -59,9 +72,26 @@
 
     private static final String TAG = "TelephonyRegistryManager";
     private static ITelephonyRegistry sRegistry;
+    private final Context mContext;
+
+    /**
+     * A mapping between {@link SubscriptionManager.OnSubscriptionsChangedListener} and
+     * its callback IOnSubscriptionsChangedListener.
+     */
+    private final Map<SubscriptionManager.OnSubscriptionsChangedListener,
+                IOnSubscriptionsChangedListener> mSubscriptionChangedListenerMap = new HashMap<>();
+    /**
+     * A mapping between {@link SubscriptionManager.OnOpportunisticSubscriptionsChangedListener} and
+     * its callback IOnSubscriptionsChangedListener.
+     */
+    private final Map<SubscriptionManager.OnOpportunisticSubscriptionsChangedListener,
+            IOnSubscriptionsChangedListener> mOpportunisticSubscriptionChangedListenerMap
+            = new HashMap<>();
+
 
     /** @hide **/
-    public TelephonyRegistryManager() {
+    public TelephonyRegistryManager(@NonNull Context context) {
+        mContext = context;
         if (sRegistry == null) {
             sRegistry = ITelephonyRegistry.Stub.asInterface(
                 ServiceManager.getService("telephony.registry"));
@@ -69,6 +99,113 @@
     }
 
     /**
+     * Register for changes to the list of active {@link SubscriptionInfo} records or to the
+     * individual records themselves. When a change occurs the onSubscriptionsChanged method of
+     * the listener will be invoked immediately if there has been a notification. The
+     * onSubscriptionChanged method will also be triggered once initially when calling this
+     * function.
+     *
+     * @param listener an instance of {@link SubscriptionManager.OnSubscriptionsChangedListener}
+     *                 with onSubscriptionsChanged overridden.
+     * @param executor the executor that will execute callbacks.
+     */
+    public void addOnSubscriptionsChangedListener(
+            @NonNull SubscriptionManager.OnSubscriptionsChangedListener listener,
+            @NonNull Executor executor) {
+        IOnSubscriptionsChangedListener callback = new IOnSubscriptionsChangedListener.Stub() {
+            @Override
+            public void onSubscriptionsChanged () {
+                Log.d(TAG, "onSubscriptionsChangedListener callback received.");
+                executor.execute(() -> listener.onSubscriptionsChanged());
+            }
+        };
+        mSubscriptionChangedListenerMap.put(listener, callback);
+        try {
+            sRegistry.addOnSubscriptionsChangedListener(mContext.getOpPackageName(), callback);
+        } catch (RemoteException ex) {
+            // system server crash
+        }
+    }
+
+    /**
+     * Unregister the {@link SubscriptionManager.OnSubscriptionsChangedListener}. This is not
+     * strictly necessary as the listener will automatically be unregistered if an attempt to
+     * invoke the listener fails.
+     *
+     * @param listener that is to be unregistered.
+     */
+    public void removeOnSubscriptionsChangedListener(
+            @NonNull SubscriptionManager.OnSubscriptionsChangedListener listener) {
+        if (mSubscriptionChangedListenerMap.get(listener) == null) {
+            return;
+        }
+        try {
+            sRegistry.removeOnSubscriptionsChangedListener(mContext.getOpPackageName(),
+                    mSubscriptionChangedListenerMap.get(listener));
+            mSubscriptionChangedListenerMap.remove(listener);
+        } catch (RemoteException ex) {
+            // system server crash
+        }
+    }
+
+    /**
+     * Register for changes to the list of opportunistic subscription records or to the
+     * individual records themselves. When a change occurs the onOpportunisticSubscriptionsChanged
+     * method of the listener will be invoked immediately if there has been a notification.
+     *
+     * @param listener an instance of
+     * {@link SubscriptionManager.OnOpportunisticSubscriptionsChangedListener} with
+     *                 onOpportunisticSubscriptionsChanged overridden.
+     * @param executor an Executor that will execute callbacks.
+     */
+    public void addOnOpportunisticSubscriptionsChangedListener(
+            @NonNull SubscriptionManager.OnOpportunisticSubscriptionsChangedListener listener,
+            @NonNull Executor executor) {
+        /**
+         * The callback methods need to be called on the executor thread where
+         * this object was created.  If the binder did that for us it'd be nice.
+         */
+        IOnSubscriptionsChangedListener callback = new IOnSubscriptionsChangedListener.Stub() {
+            @Override
+            public void onSubscriptionsChanged() {
+                final long identity = Binder.clearCallingIdentity();
+                try {
+                    Log.d(TAG, "onOpportunisticSubscriptionsChanged callback received.");
+                    executor.execute(() -> listener.onOpportunisticSubscriptionsChanged());
+                } finally {
+                    Binder.restoreCallingIdentity(identity);
+                }
+            }
+        };
+        mOpportunisticSubscriptionChangedListenerMap.put(listener, callback);
+        try {
+            sRegistry.addOnOpportunisticSubscriptionsChangedListener(mContext.getOpPackageName(),
+                    callback);
+        } catch (RemoteException ex) {
+            // system server crash
+        }
+    }
+
+    /**
+     * Unregister the {@link SubscriptionManager.OnOpportunisticSubscriptionsChangedListener}
+     * that is currently listening opportunistic subscriptions change. This is not strictly
+     * necessary as the listener will automatically be unregistered if an attempt to invoke the
+     * listener fails.
+     *
+     * @param listener that is to be unregistered.
+     */
+    public void removeOnOpportunisticSubscriptionsChangedListener(
+            @NonNull SubscriptionManager.OnOpportunisticSubscriptionsChangedListener listener) {
+        try {
+            sRegistry.removeOnSubscriptionsChangedListener(mContext.getOpPackageName(),
+                    mOpportunisticSubscriptionChangedListenerMap.get(listener));
+            mOpportunisticSubscriptionChangedListenerMap.remove(listener);
+        } catch (RemoteException ex) {
+            // system server crash
+        }
+    }
+
+    /**
      * Informs the system of an intentional upcoming carrier network change by a carrier app.
      * This call only used to allow the system to provide alternative UI while telephony is
      * performing an action that may result in intentional, temporary network lack of connectivity.
@@ -545,4 +682,15 @@
         }
     }
 
+    /**
+     * @param activeDataSubId
+     * @hide
+     */
+    public void notifyActiveDataSubIdChanged(int activeDataSubId) {
+        try {
+            sRegistry.notifyActiveDataSubIdChanged(activeDataSubId);
+        } catch (RemoteException ex) {
+
+        }
+    }
 }
diff --git a/telephony/java/com/android/internal/telephony/IOnSubscriptionsChangedListener.aidl b/core/java/com/android/internal/telephony/IOnSubscriptionsChangedListener.aidl
similarity index 100%
rename from telephony/java/com/android/internal/telephony/IOnSubscriptionsChangedListener.aidl
rename to core/java/com/android/internal/telephony/IOnSubscriptionsChangedListener.aidl
diff --git a/telephony/java/com/android/internal/telephony/IPhoneStateListener.aidl b/core/java/com/android/internal/telephony/IPhoneStateListener.aidl
similarity index 99%
rename from telephony/java/com/android/internal/telephony/IPhoneStateListener.aidl
rename to core/java/com/android/internal/telephony/IPhoneStateListener.aidl
index 90019ee..084a3cc 100644
--- a/telephony/java/com/android/internal/telephony/IPhoneStateListener.aidl
+++ b/core/java/com/android/internal/telephony/IPhoneStateListener.aidl
@@ -29,6 +29,9 @@
 import android.telephony.emergency.EmergencyNumber;
 import android.telephony.ims.ImsReasonInfo;
 
+/**
+ * {@hide}
+ */
 oneway interface IPhoneStateListener {
     void onServiceStateChanged(in ServiceState serviceState);
     void onSignalStrengthChanged(int asu);
diff --git a/telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl b/core/java/com/android/internal/telephony/ITelephonyRegistry.aidl
similarity index 100%
rename from telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl
rename to core/java/com/android/internal/telephony/ITelephonyRegistry.aidl
diff --git a/telephony/java/android/telephony/SubscriptionManager.java b/telephony/java/android/telephony/SubscriptionManager.java
index b35549e..879e48c 100644
--- a/telephony/java/android/telephony/SubscriptionManager.java
+++ b/telephony/java/android/telephony/SubscriptionManager.java
@@ -49,6 +49,7 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.Handler;
+import android.os.HandlerExecutor;
 import android.os.Looper;
 import android.os.Message;
 import android.os.ParcelUuid;
@@ -61,10 +62,8 @@
 import android.util.DisplayMetrics;
 import android.util.Log;
 
-import com.android.internal.telephony.IOnSubscriptionsChangedListener;
 import com.android.internal.telephony.ISetOpportunisticDataCallback;
 import com.android.internal.telephony.ISub;
-import com.android.internal.telephony.ITelephonyRegistry;
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.util.Preconditions;
 
@@ -925,20 +924,24 @@
             OnSubscriptionsChangedListenerHandler(Looper looper) {
                 super(looper);
             }
-
-            @Override
-            public void handleMessage(Message msg) {
-                if (DBG) {
-                    log("handleMessage: invoke the overriden onSubscriptionsChanged()");
-                }
-                OnSubscriptionsChangedListener.this.onSubscriptionsChanged();
-            }
         }
 
-        private final Handler mHandler;
+        /**
+         * Posted executor callback on the handler associated with a given looper.
+         * The looper can be the calling thread's looper or the looper passed from the
+         * constructor {@link #OnSubscriptionsChangedListener(Looper)}.
+         */
+        private final HandlerExecutor mExecutor;
+
+        /**
+         * @hide
+         */
+        public HandlerExecutor getHandlerExecutor() {
+            return mExecutor;
+        }
 
         public OnSubscriptionsChangedListener() {
-            mHandler = new OnSubscriptionsChangedListenerHandler();
+            mExecutor = new HandlerExecutor(new OnSubscriptionsChangedListenerHandler());
         }
 
         /**
@@ -947,7 +950,7 @@
          * @hide
          */
         public OnSubscriptionsChangedListener(Looper looper) {
-            mHandler = new OnSubscriptionsChangedListenerHandler(looper);
+            mExecutor = new HandlerExecutor(new OnSubscriptionsChangedListenerHandler(looper));
         }
 
         /**
@@ -959,18 +962,6 @@
             if (DBG) log("onSubscriptionsChanged: NOT OVERRIDDEN");
         }
 
-        /**
-         * The callback methods need to be called on the handler thread where
-         * this object was created.  If the binder did that for us it'd be nice.
-         */
-        IOnSubscriptionsChangedListener callback = new IOnSubscriptionsChangedListener.Stub() {
-            @Override
-            public void onSubscriptionsChanged() {
-                if (DBG) log("callback: received, sendEmptyMessage(0) to handler");
-                mHandler.sendEmptyMessage(0);
-            }
-        };
-
         private void log(String s) {
             Rlog.d(LOG_TAG, s);
         }
@@ -1012,21 +1003,19 @@
      *                 onSubscriptionsChanged overridden.
      */
     public void addOnSubscriptionsChangedListener(OnSubscriptionsChangedListener listener) {
+        if (listener == null) return;
         String pkgName = mContext != null ? mContext.getOpPackageName() : "<unknown>";
         if (DBG) {
             logd("register OnSubscriptionsChangedListener pkgName=" + pkgName
                     + " listener=" + listener);
         }
-        try {
-            // We use the TelephonyRegistry as it runs in the system and thus is always
-            // available. Where as SubscriptionController could crash and not be available
-            ITelephonyRegistry tr = ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(
-                    "telephony.registry"));
-            if (tr != null) {
-                tr.addOnSubscriptionsChangedListener(pkgName, listener.callback);
-            }
-        } catch (RemoteException ex) {
-            Log.e(LOG_TAG, "Remote exception ITelephonyRegistry " + ex);
+        // We use the TelephonyRegistry as it runs in the system and thus is always
+        // available. Where as SubscriptionController could crash and not be available
+        TelephonyRegistryManager telephonyRegistryManager = (TelephonyRegistryManager)
+                mContext.getSystemService(Context.TELEPHONY_REGISTRY_SERVICE);
+        if (telephonyRegistryManager != null) {
+            telephonyRegistryManager.addOnSubscriptionsChangedListener(listener,
+                    listener.mExecutor);
         }
     }
 
@@ -1038,21 +1027,18 @@
      * @param listener that is to be unregistered.
      */
     public void removeOnSubscriptionsChangedListener(OnSubscriptionsChangedListener listener) {
+        if (listener == null) return;
         String pkgForDebug = mContext != null ? mContext.getOpPackageName() : "<unknown>";
         if (DBG) {
             logd("unregister OnSubscriptionsChangedListener pkgForDebug=" + pkgForDebug
                     + " listener=" + listener);
         }
-        try {
-            // We use the TelephonyRegistry as it runs in the system and thus is always
-            // available where as SubscriptionController could crash and not be available
-            ITelephonyRegistry tr = ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(
-                    "telephony.registry"));
-            if (tr != null) {
-                tr.removeOnSubscriptionsChangedListener(pkgForDebug, listener.callback);
-            }
-        } catch (RemoteException ex) {
-            Log.e(LOG_TAG, "Remote exception ITelephonyRegistry " + ex);
+        // We use the TelephonyRegistry as it runs in the system and thus is always
+        // available where as SubscriptionController could crash and not be available
+        TelephonyRegistryManager telephonyRegistryManager = (TelephonyRegistryManager)
+                mContext.getSystemService(Context.TELEPHONY_REGISTRY_SERVICE);
+        if (telephonyRegistryManager != null) {
+            telephonyRegistryManager.removeOnSubscriptionsChangedListener(listener);
         }
     }
 
@@ -1071,7 +1057,6 @@
      * for #onOpportunisticSubscriptionsChanged to be invoked.
      */
     public static class OnOpportunisticSubscriptionsChangedListener {
-        private Executor mExecutor;
         /**
          * Callback invoked when there is any change to any SubscriptionInfo. Typically
          * this method would invoke {@link #getActiveSubscriptionInfoList}
@@ -1080,27 +1065,6 @@
             if (DBG) log("onOpportunisticSubscriptionsChanged: NOT OVERRIDDEN");
         }
 
-        private void setExecutor(Executor executor) {
-            mExecutor = executor;
-        }
-
-        /**
-         * The callback methods need to be called on the handler thread where
-         * this object was created.  If the binder did that for us it'd be nice.
-         */
-        IOnSubscriptionsChangedListener callback = new IOnSubscriptionsChangedListener.Stub() {
-            @Override
-            public void onSubscriptionsChanged() {
-                final long identity = Binder.clearCallingIdentity();
-                try {
-                    if (DBG) log("onOpportunisticSubscriptionsChanged callback received.");
-                    mExecutor.execute(() -> onOpportunisticSubscriptionsChanged());
-                } finally {
-                    Binder.restoreCallingIdentity(identity);
-                }
-            }
-        };
-
         private void log(String s) {
             Rlog.d(LOG_TAG, s);
         }
@@ -1127,18 +1091,13 @@
                     + " listener=" + listener);
         }
 
-        listener.setExecutor(executor);
-
-        try {
-            // We use the TelephonyRegistry as it runs in the system and thus is always
-            // available. Where as SubscriptionController could crash and not be available
-            ITelephonyRegistry tr = ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(
-                    "telephony.registry"));
-            if (tr != null) {
-                tr.addOnOpportunisticSubscriptionsChangedListener(pkgName, listener.callback);
-            }
-        } catch (RemoteException ex) {
-            Log.e(LOG_TAG, "Remote exception ITelephonyRegistry " + ex);
+        // We use the TelephonyRegistry as it runs in the system and thus is always
+        // available where as SubscriptionController could crash and not be available
+        TelephonyRegistryManager telephonyRegistryManager = (TelephonyRegistryManager)
+                mContext.getSystemService(Context.TELEPHONY_REGISTRY_SERVICE);
+        if (telephonyRegistryManager != null) {
+            telephonyRegistryManager.addOnOpportunisticSubscriptionsChangedListener(
+                    listener, executor);
         }
     }
 
@@ -1158,16 +1117,10 @@
             logd("unregister OnOpportunisticSubscriptionsChangedListener pkgForDebug="
                     + pkgForDebug + " listener=" + listener);
         }
-        try {
-            // We use the TelephonyRegistry as it runs in the system and thus is always
-            // available where as SubscriptionController could crash and not be available
-            ITelephonyRegistry tr = ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(
-                    "telephony.registry"));
-            if (tr != null) {
-                tr.removeOnSubscriptionsChangedListener(pkgForDebug, listener.callback);
-            }
-        } catch (RemoteException ex) {
-            Log.e(LOG_TAG, "Remote exception ITelephonyRegistry " + ex);
+        TelephonyRegistryManager telephonyRegistryManager = (TelephonyRegistryManager)
+                mContext.getSystemService(Context.TELEPHONY_REGISTRY_SERVICE);
+        if (telephonyRegistryManager != null) {
+            telephonyRegistryManager.removeOnOpportunisticSubscriptionsChangedListener(listener);
         }
     }