diff --git a/api/current.txt b/api/current.txt
index c544470..24e37cc 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -39428,12 +39428,15 @@
     method public final void addConference(android.telecom.Conference);
     method public final void addExistingConnection(android.telecom.PhoneAccountHandle, android.telecom.Connection);
     method public final void conferenceRemoteConnections(android.telecom.RemoteConnection, android.telecom.RemoteConnection);
+    method public final void connectionServiceFocusReleased();
     method public final android.telecom.RemoteConnection createRemoteIncomingConnection(android.telecom.PhoneAccountHandle, android.telecom.ConnectionRequest);
     method public final android.telecom.RemoteConnection createRemoteOutgoingConnection(android.telecom.PhoneAccountHandle, android.telecom.ConnectionRequest);
     method public final java.util.Collection<android.telecom.Conference> getAllConferences();
     method public final java.util.Collection<android.telecom.Connection> getAllConnections();
     method public final android.os.IBinder onBind(android.content.Intent);
     method public void onConference(android.telecom.Connection, android.telecom.Connection);
+    method public void onConnectionServiceFocusGained();
+    method public void onConnectionServiceFocusLost();
     method public android.telecom.Connection onCreateIncomingConnection(android.telecom.PhoneAccountHandle, android.telecom.ConnectionRequest);
     method public void onCreateIncomingConnectionFailed(android.telecom.PhoneAccountHandle, android.telecom.ConnectionRequest);
     method public android.telecom.Connection onCreateIncomingHandoverConnection(android.telecom.PhoneAccountHandle, android.telecom.ConnectionRequest);
diff --git a/telecomm/java/android/telecom/ConnectionService.java b/telecomm/java/android/telecom/ConnectionService.java
index 4fd602f..e37aeb4 100644
--- a/telecomm/java/android/telecom/ConnectionService.java
+++ b/telecomm/java/android/telecom/ConnectionService.java
@@ -145,6 +145,8 @@
     private static final String SESSION_STOP_RTT = "CS.-RTT";
     private static final String SESSION_RTT_UPGRADE_RESPONSE = "CS.rTRUR";
     private static final String SESSION_HANDOVER_FAILED = "CS.haF";
+    private static final String SESSION_CONNECTION_SERVICE_FOCUS_LOST = "CS.cSFL";
+    private static final String SESSION_CONNECTION_SERVICE_FOCUS_GAINED = "CS.cSFG";
 
     private static final int MSG_ADD_CONNECTION_SERVICE_ADAPTER = 1;
     private static final int MSG_CREATE_CONNECTION = 2;
@@ -174,6 +176,8 @@
     private static final int MSG_ON_STOP_RTT = 27;
     private static final int MSG_RTT_UPGRADE_RESPONSE = 28;
     private static final int MSG_CREATE_CONNECTION_COMPLETE = 29;
+    private static final int MSG_CONNECTION_SERVICE_FOCUS_LOST = 30;
+    private static final int MSG_CONNECTION_SERVICE_FOCUS_GAINED = 31;
     private static final int MSG_HANDOVER_FAILED = 32;
 
     private static Connection sNullConnection;
@@ -610,6 +614,26 @@
                 Log.endSession();
             }
         }
+
+        @Override
+        public void connectionServiceFocusLost(Session.Info sessionInfo) throws RemoteException {
+            Log.startSession(sessionInfo, SESSION_CONNECTION_SERVICE_FOCUS_LOST);
+            try {
+                mHandler.obtainMessage(MSG_CONNECTION_SERVICE_FOCUS_LOST).sendToTarget();
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        @Override
+        public void connectionServiceFocusGained(Session.Info sessionInfo) throws RemoteException {
+            Log.startSession(sessionInfo, SESSION_CONNECTION_SERVICE_FOCUS_GAINED);
+            try {
+                mHandler.obtainMessage(MSG_CONNECTION_SERVICE_FOCUS_GAINED).sendToTarget();
+            } finally {
+                Log.endSession();
+            }
+        }
     };
 
     private final Handler mHandler = new Handler(Looper.getMainLooper()) {
@@ -1061,6 +1085,12 @@
                     }
                     break;
                 }
+                case MSG_CONNECTION_SERVICE_FOCUS_GAINED:
+                    onConnectionServiceFocusGained();
+                    break;
+                case MSG_CONNECTION_SERVICE_FOCUS_LOST:
+                    onConnectionServiceFocusLost();
+                    break;
                 default:
                     break;
             }
@@ -1930,6 +1960,16 @@
     }
 
     /**
+     * Call to inform Telecom that your {@link ConnectionService} has released call resources (e.g
+     * microphone, camera).
+     *
+     * @see ConnectionService#onConnectionServiceFocusLost()
+     */
+    public final void connectionServiceFocusReleased() {
+        mAdapter.onConnectionServiceFocusReleased();
+    }
+
+    /**
      * Adds a connection created by the {@link ConnectionService} and informs telecom of the new
      * connection.
      *
@@ -2179,6 +2219,20 @@
     public void onRemoteExistingConnectionAdded(RemoteConnection connection) {}
 
     /**
+     * Called when the {@link ConnectionService} has lost the call focus.
+     * The {@link ConnectionService} should release the call resources and invokes
+     * {@link ConnectionService#connectionServiceFocusReleased()} to inform telecom that it has
+     * released the call resources.
+     */
+    public void onConnectionServiceFocusLost() {}
+
+    /**
+     * Called when the {@link ConnectionService} has gained the call focus. The
+     * {@link ConnectionService} can acquire the call resources at this time.
+     */
+    public void onConnectionServiceFocusGained() {}
+
+    /**
      * @hide
      */
     public boolean containsConference(Conference conference) {
diff --git a/telecomm/java/android/telecom/ConnectionServiceAdapter.java b/telecomm/java/android/telecom/ConnectionServiceAdapter.java
index 92a9dc2..0d319bb 100644
--- a/telecomm/java/android/telecom/ConnectionServiceAdapter.java
+++ b/telecomm/java/android/telecom/ConnectionServiceAdapter.java
@@ -628,4 +628,17 @@
             }
         }
     }
+
+    /**
+     * Notifies Telecom that the {@link ConnectionService} has released the call resource.
+     */
+    void onConnectionServiceFocusReleased() {
+        for (IConnectionServiceAdapter adapter : mAdapters) {
+            try {
+                Log.d(this, "onConnectionServiceFocusReleased");
+                adapter.onConnectionServiceFocusReleased(Log.getExternalSession());
+            } catch (RemoteException ignored) {
+            }
+        }
+    }
 }
diff --git a/telecomm/java/android/telecom/ConnectionServiceAdapterServant.java b/telecomm/java/android/telecom/ConnectionServiceAdapterServant.java
index 3fbdeb1..3e1bf77 100644
--- a/telecomm/java/android/telecom/ConnectionServiceAdapterServant.java
+++ b/telecomm/java/android/telecom/ConnectionServiceAdapterServant.java
@@ -73,6 +73,7 @@
     private static final int MSG_ON_RTT_REMOTELY_TERMINATED = 32;
     private static final int MSG_ON_RTT_UPGRADE_REQUEST = 33;
     private static final int MSG_SET_PHONE_ACCOUNT_CHANGED = 34;
+    private static final int MSG_CONNECTION_SERVICE_FOCUS_RELEASED = 35;
 
     private final IConnectionServiceAdapter mDelegate;
 
@@ -329,6 +330,9 @@
                     }
                     break;
                 }
+                case MSG_CONNECTION_SERVICE_FOCUS_RELEASED:
+                    mDelegate.onConnectionServiceFocusReleased(null /*Session.Info*/);
+                    break;
             }
         }
     };
@@ -601,6 +605,11 @@
             args.arg2 = pHandle;
             mHandler.obtainMessage(MSG_SET_PHONE_ACCOUNT_CHANGED, args).sendToTarget();
         }
+
+        @Override
+        public void onConnectionServiceFocusReleased(Session.Info sessionInfo) {
+            mHandler.obtainMessage(MSG_CONNECTION_SERVICE_FOCUS_RELEASED).sendToTarget();
+        }
     };
 
     public ConnectionServiceAdapterServant(IConnectionServiceAdapter delegate) {
diff --git a/telecomm/java/android/telecom/RemoteConnectionService.java b/telecomm/java/android/telecom/RemoteConnectionService.java
index 85906ad..59ce590 100644
--- a/telecomm/java/android/telecom/RemoteConnectionService.java
+++ b/telecomm/java/android/telecom/RemoteConnectionService.java
@@ -213,6 +213,9 @@
         }
 
         @Override
+        public void onConnectionServiceFocusReleased(Session.Info sessionInfo) {}
+
+        @Override
         public void addConferenceCall(
                 final String callId, ParcelableConference parcel, Session.Info sessionInfo) {
             RemoteConference conference = new RemoteConference(callId,
diff --git a/telecomm/java/com/android/internal/telecom/IConnectionService.aidl b/telecomm/java/com/android/internal/telecom/IConnectionService.aidl
index 732d00d..02e1ff8 100644
--- a/telecomm/java/com/android/internal/telecom/IConnectionService.aidl
+++ b/telecomm/java/com/android/internal/telecom/IConnectionService.aidl
@@ -103,4 +103,8 @@
 
     void handoverFailed(String callId, in ConnectionRequest request,
             int error, in Session.Info sessionInfo);
+
+    void connectionServiceFocusLost(in Session.Info sessionInfo);
+
+    void connectionServiceFocusGained(in Session.Info sessionInfo);
 }
diff --git a/telecomm/java/com/android/internal/telecom/IConnectionServiceAdapter.aidl b/telecomm/java/com/android/internal/telecom/IConnectionServiceAdapter.aidl
index da2015f..be474bd 100644
--- a/telecomm/java/com/android/internal/telecom/IConnectionServiceAdapter.aidl
+++ b/telecomm/java/com/android/internal/telecom/IConnectionServiceAdapter.aidl
@@ -119,4 +119,6 @@
 
     void onPhoneAccountChanged(String callId, in PhoneAccountHandle pHandle,
     in Session.Info sessionInfo);
+
+    void onConnectionServiceFocusReleased(in Session.Info sessionInfo);
 }