diff --git a/telecomm/java/android/telecom/Call.java b/telecomm/java/android/telecom/Call.java
index f54f8d1..005fcac 100644
--- a/telecomm/java/android/telecom/Call.java
+++ b/telecomm/java/android/telecom/Call.java
@@ -539,7 +539,7 @@
          *
          * @see TelecomManager#EXTRA_USE_ASSISTED_DIALING
          */
-        public static final int PROPERTY_ASSISTED_DIALING_USED = 0x00000200;
+        public static final int PROPERTY_ASSISTED_DIALING = 0x00000200;
 
         /**
          * Indicates that the call is an RTT call. Use {@link #getRttCall()} to get the
@@ -743,7 +743,7 @@
             if (hasProperty(properties, PROPERTY_HAS_CDMA_VOICE_PRIVACY)) {
                 builder.append(" PROPERTY_HAS_CDMA_VOICE_PRIVACY");
             }
-            if (hasProperty(properties, PROPERTY_ASSISTED_DIALING_USED)) {
+            if (hasProperty(properties, PROPERTY_ASSISTED_DIALING)) {
                 builder.append(" PROPERTY_ASSISTED_DIALING_USED");
             }
             if (hasProperty(properties, PROPERTY_NETWORK_IDENTIFIED_EMERGENCY_CALL)) {
diff --git a/telecomm/java/android/telecom/Conference.java b/telecomm/java/android/telecom/Conference.java
index 6b0845f..97fa2b4 100644
--- a/telecomm/java/android/telecom/Conference.java
+++ b/telecomm/java/android/telecom/Conference.java
@@ -16,8 +16,13 @@
 
 package android.telecom;
 
+import static android.Manifest.permission.MODIFY_PHONE_STATE;
+
+import android.annotation.ElapsedRealtimeLong;
+import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.net.Uri;
@@ -620,12 +625,12 @@
      * Should be specified in wall-clock time returned by {@link System#currentTimeMillis()}.
      * <p>
      * When setting the connection time, you should always set the connection elapsed time via
-     * {@link #setConnectionStartElapsedRealTime(long)} to ensure the duration is reflected.
+     * {@link #setConnectionStartElapsedRealtimeMillis(long)} to ensure the duration is reflected.
      *
      * @param connectionTimeMillis The connection time, in milliseconds, as returned by
      *                             {@link System#currentTimeMillis()}.
      */
-    public final void setConnectionTime(long connectionTimeMillis) {
+    public final void setConnectionTime(@IntRange(from = 0) long connectionTimeMillis) {
         mConnectTimeMillis = connectionTimeMillis;
     }
 
@@ -641,8 +646,28 @@
      *
      * @param connectionStartElapsedRealTime The connection time, as measured by
      * {@link SystemClock#elapsedRealtime()}.
+     * @deprecated use {@link #setConnectionStartElapsedRealtimeMillis(long)} instead.
      */
+    @Deprecated
     public final void setConnectionStartElapsedRealTime(long connectionStartElapsedRealTime) {
+        setConnectionStartElapsedRealtimeMillis(connectionStartElapsedRealTime);
+    }
+
+    /**
+     * Sets the start time of the {@link Conference} which is the basis for the determining the
+     * duration of the {@link Conference}.
+     * <p>
+     * You should use a value returned by {@link SystemClock#elapsedRealtime()} to ensure that time
+     * zone changes do not impact the conference duration.
+     * <p>
+     * When setting this, you should also set the connection time via
+     * {@link #setConnectionTime(long)}.
+     *
+     * @param connectionStartElapsedRealTime The connection time, as measured by
+     * {@link SystemClock#elapsedRealtime()}.
+     */
+    public final void setConnectionStartElapsedRealtimeMillis(
+            @ElapsedRealtimeLong long connectionStartElapsedRealTime) {
         mConnectionStartElapsedRealTime = connectionStartElapsedRealTime;
     }
 
@@ -663,7 +688,7 @@
      *
      * @return The time at which the {@code Conference} was connected.
      */
-    public final long getConnectionTime() {
+    public final @IntRange(from = 0) long getConnectionTime() {
         return mConnectTimeMillis;
     }
 
@@ -680,11 +705,8 @@
      * has no general use other than to the Telephony framework.
      *
      * @return The elapsed time at which the {@link Conference} was connected.
-     * @hide
      */
-    @SystemApi
-    @TestApi
-    public final long getConnectionStartElapsedRealTime() {
+    public final @ElapsedRealtimeLong long getConnectionStartElapsedRealtimeMillis() {
         return mConnectionStartElapsedRealTime;
     }
 
@@ -981,6 +1003,7 @@
      */
     @SystemApi
     @TestApi
+    @RequiresPermission(MODIFY_PHONE_STATE)
     public void setConferenceState(boolean isConference) {
         for (Listener l : mListeners) {
             l.onConferenceStateChanged(this, isConference);
@@ -1001,6 +1024,7 @@
      */
     @SystemApi
     @TestApi
+    @RequiresPermission(MODIFY_PHONE_STATE)
     public final void setAddress(@NonNull Uri address,
             @TelecomManager.Presentation int presentation) {
         Log.d(this, "setAddress %s", address);
@@ -1107,12 +1131,52 @@
     }
 
     /**
-     * Sends an event associated with this {@code Conference} with associated event extras to the
-     * {@link InCallService} (note: this is identical in concept to
-     * {@link Connection#sendConnectionEvent(String, Bundle)}).
-     * @see Connection#sendConnectionEvent(String, Bundle)
+     * Sends an event associated with this {@link Conference} with associated event extras to the
+     * {@link InCallService}.
+     * <p>
+     * Connection events are used to communicate point in time information from a
+     * {@link ConnectionService} to an {@link InCallService} implementation.  An example of a
+     * custom connection event includes notifying the UI when a WIFI call has been handed over to
+     * LTE, which the InCall UI might use to inform the user that billing charges may apply.  The
+     * Android Telephony framework will send the {@link Connection#EVENT_MERGE_COMPLETE}
+     * connection event when a call to {@link Call#mergeConference()} has completed successfully.
+     * <p>
+     * Events are exposed to {@link InCallService} implementations via
+     * {@link Call.Callback#onConnectionEvent(Call, String, Bundle)}.
+     * <p>
+     * No assumptions should be made as to how an In-Call UI or service will handle these events.
+     * The {@link ConnectionService} must assume that the In-Call UI could even chose to ignore
+     * some events altogether.
+     * <p>
+     * Events should be fully qualified (e.g. {@code com.example.event.MY_EVENT}) to avoid
+     * conflicts between {@link ConnectionService} implementations.  Further, custom
+     * {@link ConnectionService} implementations shall not re-purpose events in the
+     * {@code android.*} namespace, nor shall they define new event types in this namespace.  When
+     * defining a custom event type, ensure the contents of the extras {@link Bundle} is clearly
+     * defined.  Extra keys for this bundle should be named similar to the event type (e.g.
+     * {@code com.example.extra.MY_EXTRA}).
+     * <p>
+     * When defining events and the associated extras, it is important to keep their behavior
+     * consistent when the associated {@link ConnectionService} is updated.  Support for deprecated
+     * events/extras should me maintained to ensure backwards compatibility with older
+     * {@link InCallService} implementations which were built to support the older behavior.
+     * <p>
+     * Expected connection events from the Telephony stack are:
+     * <p>
+     * <ul>
+     *      <li>{@link Connection#EVENT_CALL_HOLD_FAILED} with {@code null} {@code extras} when the
+     *      {@link Conference} could not be held.</li>
+     *      <li>{@link Connection#EVENT_MERGE_START} with {@code null} {@code extras} when a new
+     *      call is being merged into the conference.</li>
+     *      <li>{@link Connection#EVENT_MERGE_COMPLETE} with {@code null} {@code extras} a new call
+     *      has completed being merged into the conference.</li>
+     *      <li>{@link Connection#EVENT_CALL_MERGE_FAILED} with {@code null} {@code extras} a new
+     *      call has failed to merge into the conference (the dialer app can determine which call
+     *      failed to merge based on the fact that the call still exists outside of the conference
+     *      at the end of the merge process).</li>
+     * </ul>
      *
-     * @param event The connection event.
+     * @param event The conference event.
      * @param extras Optional bundle containing extra information associated with the event.
      */
     public void sendConferenceEvent(@NonNull String event, @Nullable Bundle extras) {
diff --git a/telecomm/java/android/telecom/Connection.java b/telecomm/java/android/telecom/Connection.java
index 72c66d2..7e5e32d 100644
--- a/telecomm/java/android/telecom/Connection.java
+++ b/telecomm/java/android/telecom/Connection.java
@@ -16,9 +16,14 @@
 
 package android.telecom;
 
+import static android.Manifest.permission.MODIFY_PHONE_STATE;
+
+import android.annotation.ElapsedRealtimeLong;
 import android.annotation.IntDef;
+import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.app.Notification;
@@ -474,7 +479,7 @@
      *
      * @see TelecomManager#EXTRA_USE_ASSISTED_DIALING
      */
-    public static final int PROPERTY_ASSISTED_DIALING_USED = 1 << 9;
+    public static final int PROPERTY_ASSISTED_DIALING = 1 << 9;
 
     /**
      * Set by the framework to indicate that the network has identified a Connection as an emergency
@@ -2109,19 +2114,24 @@
      */
     @SystemApi
     @TestApi
-    public final long getConnectTimeMillis() {
+    public final @IntRange(from = 0) long getConnectTimeMillis() {
         return mConnectTimeMillis;
     }
 
     /**
      * Retrieves the connection start time of the {@link Connection}, if specified.  A value of
      * {@link Conference#CONNECT_TIME_NOT_SPECIFIED} indicates that Telecom should determine the
-     * start time of the conference.
+     * start time of the connection.
      * <p>
      * Based on the value of {@link SystemClock#elapsedRealtime()}, which ensures that wall-clock
      * changes do not impact the call duration.
      * <p>
      * Used internally in Telephony when migrating conference participant data for IMS conferences.
+     * <p>
+     * The value returned is the same one set using
+     * {@link #setConnectionStartElapsedRealtimeMillis(long)}.  This value is never updated from
+     * the Telecom framework, so no permission enforcement occurs when retrieving the value with
+     * this method.
      *
      * @return The time at which the {@link Connection} was connected.
      *
@@ -2129,7 +2139,7 @@
      */
     @SystemApi
     @TestApi
-    public final long getConnectElapsedTimeMillis() {
+    public final @ElapsedRealtimeLong long getConnectionStartElapsedRealtimeMillis() {
         return mConnectElapsedTimeMillis;
     }
 
@@ -2550,6 +2560,9 @@
      * Sets the time at which a call became active on this Connection. This is set only
      * when a conference call becomes active on this connection.
      * <p>
+     * This time corresponds to the date/time of connection and is stored in the call log in
+     * {@link android.provider.CallLog.Calls#DATE}.
+     * <p>
      * Used by telephony to maintain calls associated with an IMS Conference.
      *
      * @param connectTimeMillis The connection time, in milliseconds.  Should be set using a value
@@ -2559,7 +2572,8 @@
      */
     @SystemApi
     @TestApi
-    public final void setConnectTimeMillis(long connectTimeMillis) {
+    @RequiresPermission(MODIFY_PHONE_STATE)
+    public final void setConnectTimeMillis(@IntRange(from = 0) long connectTimeMillis) {
         mConnectTimeMillis = connectTimeMillis;
     }
 
@@ -2567,15 +2581,23 @@
      * Sets the time at which a call became active on this Connection. This is set only
      * when a conference call becomes active on this connection.
      * <p>
+     * This time is used to establish the duration of a call.  It uses
+     * {@link SystemClock#elapsedRealtime()} to ensure that the call duration is not impacted by
+     * time zone changes during a call.  The difference between the current
+     * {@link SystemClock#elapsedRealtime()} and the value set at the connection start time is used
+     * to populate {@link android.provider.CallLog.Calls#DURATION} in the call log.
+     * <p>
      * Used by telephony to maintain calls associated with an IMS Conference.
+     *
      * @param connectElapsedTimeMillis The connection time, in milliseconds.  Stored in the format
      *                              {@link SystemClock#elapsedRealtime()}.
-     *
      * @hide
      */
     @SystemApi
     @TestApi
-    public final void setConnectionStartElapsedRealTime(long connectElapsedTimeMillis) {
+    @RequiresPermission(MODIFY_PHONE_STATE)
+    public final void setConnectionStartElapsedRealtimeMillis(
+            @ElapsedRealtimeLong long connectElapsedTimeMillis) {
         mConnectElapsedTimeMillis = connectElapsedTimeMillis;
     }
 
diff --git a/telecomm/java/android/telecom/ConnectionService.java b/telecomm/java/android/telecom/ConnectionService.java
index 00c2918..f77e529 100644
--- a/telecomm/java/android/telecom/ConnectionService.java
+++ b/telecomm/java/android/telecom/ConnectionService.java
@@ -18,7 +18,6 @@
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
-import android.annotation.RequiresPermission;
 import android.annotation.SdkConstant;
 import android.annotation.SystemApi;
 import android.app.Service;
@@ -1778,7 +1777,7 @@
                         null : conference.getVideoProvider().getInterface(),
                 conference.getVideoState(),
                 conference.getConnectTimeMillis(),
-                conference.getConnectionStartElapsedRealTime(),
+                conference.getConnectionStartElapsedRealtimeMillis(),
                 conference.getStatusHints(),
                 conference.getExtras(),
                 conference.getAddress(),
@@ -1884,7 +1883,7 @@
                         connection.isRingbackRequested(),
                         connection.getAudioModeIsVoip(),
                         connection.getConnectTimeMillis(),
-                        connection.getConnectElapsedTimeMillis(),
+                        connection.getConnectionStartElapsedRealtimeMillis(),
                         connection.getStatusHints(),
                         connection.getDisconnectCause(),
                         createIdList(connection.getConferenceables()),
@@ -2374,7 +2373,7 @@
                             null : conference.getVideoProvider().getInterface(),
                     conference.getVideoState(),
                     conference.getConnectTimeMillis(),
-                    conference.getConnectionStartElapsedRealTime(),
+                    conference.getConnectionStartElapsedRealtimeMillis(),
                     conference.getStatusHints(),
                     conference.getExtras(),
                     conference.getAddress(),
@@ -2465,7 +2464,7 @@
                     connection.isRingbackRequested(),
                     connection.getAudioModeIsVoip(),
                     connection.getConnectTimeMillis(),
-                    connection.getConnectElapsedTimeMillis(),
+                    connection.getConnectionStartElapsedRealtimeMillis(),
                     connection.getStatusHints(),
                     connection.getDisconnectCause(),
                     emptyList,
diff --git a/telecomm/java/android/telecom/PhoneAccount.java b/telecomm/java/android/telecom/PhoneAccount.java
index f00432b..4e6e1a5 100644
--- a/telecomm/java/android/telecom/PhoneAccount.java
+++ b/telecomm/java/android/telecom/PhoneAccount.java
@@ -16,7 +16,10 @@
 
 package android.telecom;
 
+import static android.Manifest.permission.MODIFY_PHONE_STATE;
+
 import android.annotation.NonNull;
+import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.content.Intent;
@@ -614,7 +617,8 @@
          * time. By default, there is no group Id for a {@link PhoneAccount} (an empty String). Only
          * grouped {@link PhoneAccount}s with the same {@link ConnectionService} can be replaced.
          * <p>
-         * Note: This is an API specific to the Telephony stack.
+         * Note: This is an API specific to the Telephony stack; the group Id will be ignored for
+         * callers not holding the correct permission.
          *
          * @param groupId The group Id of the {@link PhoneAccount} that will replace any other
          * registered {@link PhoneAccount} in Telecom with the same Group Id.
@@ -623,6 +627,7 @@
          */
         @SystemApi
         @TestApi
+        @RequiresPermission(MODIFY_PHONE_STATE)
         public @NonNull Builder setGroupId(@NonNull String groupId) {
             if (groupId != null) {
                 mGroupId = groupId;
diff --git a/telecomm/java/android/telecom/TelecomManager.java b/telecomm/java/android/telecom/TelecomManager.java
index bf4dee2..ea205ce 100644
--- a/telecomm/java/android/telecom/TelecomManager.java
+++ b/telecomm/java/android/telecom/TelecomManager.java
@@ -819,8 +819,8 @@
      * automatically add dialing prefixes when placing international calls.
      * <p>
      * Setting this extra on the outgoing call extras will cause the
-     * {@link Connection#PROPERTY_ASSISTED_DIALING_USED} property and
-     * {@link Call.Details#PROPERTY_ASSISTED_DIALING_USED} property to be set on the
+     * {@link Connection#PROPERTY_ASSISTED_DIALING} property and
+     * {@link Call.Details#PROPERTY_ASSISTED_DIALING} property to be set on the
      * {@link Connection}/{@link Call} in question.  When the call is logged to the call log, the
      * {@link android.provider.CallLog.Calls#FEATURES_ASSISTED_DIALING_USED} call feature is set to
      * indicate that assisted dialing was used for the call.
@@ -1412,7 +1412,7 @@
     /**
      * Used to determine the currently selected default dialer package for a specific user.
      *
-     * @param userId the user id to query the default dialer package for.
+     * @param userHandle the user id to query the default dialer package for.
      * @return package name for the default dialer package or null if no package has been
      *         selected as the default dialer.
      * @hide
@@ -1420,10 +1420,11 @@
     @SystemApi
     @TestApi
     @RequiresPermission(READ_PRIVILEGED_PHONE_STATE)
-    public @Nullable String getDefaultDialerPackage(int userId) {
+    public @Nullable String getDefaultDialerPackage(@NonNull UserHandle userHandle) {
         try {
             if (isServiceConnected()) {
-                return getTelecomService().getDefaultDialerPackageForUser(userId);
+                return getTelecomService().getDefaultDialerPackageForUser(
+                        userHandle.getIdentifier());
             }
         } catch (RemoteException e) {
             Log.e(TAG, "RemoteException attempting to get the default dialer package name.", e);