diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index f14b672878117..40e3e6e599000 100755
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -5923,6 +5923,36 @@ public final class Settings {
         public static final int INCALL_POWER_BUTTON_BEHAVIOR_DEFAULT =
                 INCALL_POWER_BUTTON_BEHAVIOR_SCREEN_OFF;
 
+        /**
+         * What happens when the user presses the Back button while in-call
+         * and the screen is on.<br/>
+         * <b>Values:</b><br/>
+         * 0 - The Back buttons does nothing different.<br/>
+         * 1 - The Back button hangs up the current call.<br/>
+         *
+         * @hide
+         */
+        public static final String INCALL_BACK_BUTTON_BEHAVIOR = "incall_back_button_behavior";
+
+        /**
+         * INCALL_BACK_BUTTON_BEHAVIOR value for no action.
+         * @hide
+         */
+        public static final int INCALL_BACK_BUTTON_BEHAVIOR_NONE = 0x0;
+
+        /**
+         * INCALL_BACK_BUTTON_BEHAVIOR value for "hang up".
+         * @hide
+         */
+        public static final int INCALL_BACK_BUTTON_BEHAVIOR_HANGUP = 0x1;
+
+        /**
+         * INCALL_POWER_BUTTON_BEHAVIOR default value.
+         * @hide
+         */
+        public static final int INCALL_BACK_BUTTON_BEHAVIOR_DEFAULT =
+                INCALL_BACK_BUTTON_BEHAVIOR_NONE;
+
         /**
          * Whether the device should wake when the wake gesture sensor detects motion.
          * @hide
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index 422c00f19ae26..c4834f58c01aa 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -647,6 +647,9 @@ public class PhoneWindowManager implements WindowManagerPolicy {
     // (See Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR.)
     int mIncallPowerBehavior;
 
+    // Behavior of Back button while in-call and screen on
+    int mIncallBackBehavior;
+
     Display mDisplay;
 
     private int mDisplayRotation;
@@ -837,6 +840,9 @@ public class PhoneWindowManager implements WindowManagerPolicy {
             resolver.registerContentObserver(Settings.Secure.getUriFor(
                     Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR), false, this,
                     UserHandle.USER_ALL);
+            resolver.registerContentObserver(Settings.Secure.getUriFor(
+                    Settings.Secure.INCALL_BACK_BUTTON_BEHAVIOR), false, this,
+                    UserHandle.USER_ALL);
             resolver.registerContentObserver(Settings.Secure.getUriFor(
                     Settings.Secure.WAKE_GESTURE_ENABLED), false, this,
                     UserHandle.USER_ALL);
@@ -1060,7 +1066,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
             if (mBackKeyPressCounter <= PANIC_PRESS_BACK_COUNT) {
                 // This could be a multi-press.  Wait a little bit longer to confirm.
                 Message msg = mHandler.obtainMessage(MSG_BACK_DELAYED_PRESS,
-                        mBackKeyPressCounter, 0, eventTime);
+                    mBackKeyPressCounter, 0, eventTime);
                 msg.setAsynchronous(true);
                 mHandler.sendMessageDelayed(msg, ViewConfiguration.getMultiPressTimeout());
             }
@@ -1069,6 +1075,27 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         // Reset back long press state
         cancelPendingBackKeyAction();
 
+        if (mHasFeatureWatch) {
+            TelecomManager telecomManager = getTelecommService();
+
+            if (telecomManager != null) {
+                if (telecomManager.isRinging()) {
+                    // Pressing back while there's a ringing incoming
+                    // call should silence the ringer.
+                    telecomManager.silenceRinger();
+
+                    // It should not prevent navigating away
+                    return false;
+                } else if (
+                    (mIncallBackBehavior & Settings.Secure.INCALL_BACK_BUTTON_BEHAVIOR_HANGUP) != 0
+                        && telecomManager.isInCall()) {
+                    // Otherwise, if "Back button ends call" is enabled,
+                    // the Back button will hang up any current active call.
+                    return telecomManager.endCall();
+                }
+            }
+        }
+
         return handled;
     }
 
@@ -2020,6 +2047,10 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                     Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR,
                     Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_DEFAULT,
                     UserHandle.USER_CURRENT);
+            mIncallBackBehavior = Settings.Secure.getIntForUser(resolver,
+                    Settings.Secure.INCALL_BACK_BUTTON_BEHAVIOR,
+                    Settings.Secure.INCALL_BACK_BUTTON_BEHAVIOR_DEFAULT,
+                    UserHandle.USER_CURRENT);
 
             // Configure wake gesture.
             boolean wakeGestureEnabledSetting = Settings.Secure.getIntForUser(resolver,
@@ -8040,6 +8071,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                 pw.print(" mLockScreenTimerActive="); pw.println(mLockScreenTimerActive);
         pw.print(prefix); pw.print("mEndcallBehavior="); pw.print(mEndcallBehavior);
                 pw.print(" mIncallPowerBehavior="); pw.print(mIncallPowerBehavior);
+                pw.print(" mIncallBackBehavior="); pw.print(mIncallBackBehavior);
                 pw.print(" mLongPressOnHomeBehavior="); pw.println(mLongPressOnHomeBehavior);
         pw.print(prefix); pw.print("mLandscapeRotation="); pw.print(mLandscapeRotation);
                 pw.print(" mSeascapeRotation="); pw.println(mSeascapeRotation);