diff --git a/api/system-current.txt b/api/system-current.txt
index 44a1c0d79c134..e9eea1b79963c 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -93,6 +93,7 @@ package android {
     field public static final String INTERNAL_SYSTEM_WINDOW = "android.permission.INTERNAL_SYSTEM_WINDOW";
     field public static final String INVOKE_CARRIER_SETUP = "android.permission.INVOKE_CARRIER_SETUP";
     field public static final String KILL_UID = "android.permission.KILL_UID";
+    field public static final String LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH = "android.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH";
     field public static final String LOCAL_MAC_ADDRESS = "android.permission.LOCAL_MAC_ADDRESS";
     field public static final String LOCK_DEVICE = "android.permission.LOCK_DEVICE";
     field public static final String LOOP_RADIO = "android.permission.LOOP_RADIO";
@@ -9083,6 +9084,7 @@ package android.telephony {
     method public void onRadioPowerStateChanged(int);
     method public void onSrvccStateChanged(int);
     method public void onVoiceActivationStateChanged(int);
+    field @RequiresPermission(android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH) public static final int LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH = 512; // 0x200
     field @RequiresPermission("android.permission.READ_PRECISE_PHONE_STATE") public static final int LISTEN_CALL_ATTRIBUTES_CHANGED = 67108864; // 0x4000000
     field @RequiresPermission(android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION) public static final int LISTEN_OUTGOING_EMERGENCY_CALL = 268435456; // 0x10000000
     field @RequiresPermission(android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION) public static final int LISTEN_OUTGOING_EMERGENCY_SMS = 536870912; // 0x20000000
@@ -9534,6 +9536,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.CONNECTIVITY_INTERNAL) public void resetSettings();
     method @Deprecated @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public int setAllowedCarriers(int, java.util.List<android.service.carrier.CarrierIdentifier>);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean setAllowedNetworkTypes(long);
+    method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setAlwaysReportSignalStrength(boolean);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setCarrierDataEnabled(boolean);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public int setCarrierRestrictionRules(@NonNull android.telephony.CarrierRestrictionRules);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setDataActivationState(int);
diff --git a/core/java/android/telephony/PhoneStateListener.java b/core/java/android/telephony/PhoneStateListener.java
index f886cf58b8506..03e7361159e1b 100644
--- a/core/java/android/telephony/PhoneStateListener.java
+++ b/core/java/android/telephony/PhoneStateListener.java
@@ -167,6 +167,16 @@ public class PhoneStateListener {
      */
     public static final int LISTEN_SIGNAL_STRENGTHS                         = 0x00000100;
 
+    /**
+     * Listen for always reported changes of the network signal strengths (cellular),
+     * even in some situations such as the screen of the device is off.
+     *
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)
+    @SystemApi
+    public static final int LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH          = 0x00000200;
+
     /**
      * Listen for changes to observed cell info.
      *
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 5c204aba49a17..0c0493ba65aa8 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2082,6 +2082,11 @@
     <permission android:name="android.permission.READ_ACTIVE_EMERGENCY_SESSION"
         android:protectionLevel="signature" />
 
+    <!-- @SystemApi Allows listen permission to always reported signal strength.
+         @hide Used internally. -->
+    <permission android:name="android.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH"
+        android:protectionLevel="signature|telephony" />
+
     <!-- @SystemApi Protects the ability to register any PhoneAccount with
          PhoneAccount#CAPABILITY_SIM_SUBSCRIPTION. This capability indicates that the PhoneAccount
          corresponds to a device SIM.
diff --git a/services/core/java/com/android/server/TelephonyRegistry.java b/services/core/java/com/android/server/TelephonyRegistry.java
index 62743aac55f63..5eacb28c76a99 100644
--- a/services/core/java/com/android/server/TelephonyRegistry.java
+++ b/services/core/java/com/android/server/TelephonyRegistry.java
@@ -882,6 +882,10 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                             remove(r.binder);
                         }
                     }
+                    if ((events & PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)
+                            != 0) {
+                        updateReportSignalStrengthDecision(r.subId);
+                    }
                     if (validateEventsAndUserLocked(r, PhoneStateListener.LISTEN_CELL_INFO)) {
                         try {
                             if (DBG_LOC) log("listen: mCellInfo[" + phoneId + "] = "
@@ -1005,6 +1009,27 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         }
     }
 
+    private void updateReportSignalStrengthDecision(int subscriptionId) {
+        synchronized (mRecords) {
+            TelephonyManager telephonyManager = (TelephonyManager) mContext
+                    .getSystemService(Context.TELEPHONY_SERVICE);
+            for (Record r : mRecords) {
+                // If any of the system clients wants to always listen to signal strength,
+                // we need to set it on.
+                if (r.matchPhoneStateListenerEvent(
+                        PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)) {
+                    telephonyManager.createForSubscriptionId(subscriptionId)
+                            .setAlwaysReportSignalStrength(true);
+                    return;
+                }
+            }
+            // If none of the system clients wants to always listen to signal strength,
+            // we need to set it off.
+            telephonyManager.createForSubscriptionId(subscriptionId)
+                    .setAlwaysReportSignalStrength(false);
+        }
+    }
+
     private String getCallIncomingNumber(Record record, int phoneId) {
         // Only reveal the incoming number if the record has read call log permission.
         return record.canReadCallLog() ? mCallIncomingNumber[phoneId] : "";
@@ -1062,6 +1087,14 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                     }
 
                     mRecords.remove(i);
+
+                    // Every time a client that is registrating to always receive the signal
+                    // strength is removed from registry records, we need to check if
+                    // the signal strength decision needs to update on its slot.
+                    if (r.matchPhoneStateListenerEvent(
+                            PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH)) {
+                        updateReportSignalStrengthDecision(r.subId);
+                    }
                     return;
                 }
             }
@@ -2415,6 +2448,11 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                     android.Manifest.permission.READ_ACTIVE_EMERGENCY_SESSION, null);
         }
 
+        if ((events & PhoneStateListener.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH) != 0) {
+            mContext.enforceCallingOrSelfPermission(
+                    android.Manifest.permission.LISTEN_ALWAYS_REPORTED_SIGNAL_STRENGTH, null);
+        }
+
         if ((events & PhoneStateListener.LISTEN_OEM_HOOK_RAW_EVENT) != 0) {
             mContext.enforceCallingOrSelfPermission(
                     android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE, null);
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 173f84e81dae0..ac2a0e55bad8c 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -10576,6 +10576,27 @@ public class TelephonyManager {
         return true;
     }
 
+    /**
+     * Enable or disable signal strength changes from radio will always be reported in any
+     * condition (e.g. screen is off). This is only allowed for System caller.
+     *
+     * @param isEnabled {@code true} for enabling; {@code false} for disabling.
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE)
+    public void setAlwaysReportSignalStrength(boolean isEnabled) {
+        try {
+            ITelephony telephony = getITelephony();
+            if (telephony != null) {
+                telephony.setAlwaysReportSignalStrength(getSubId(), isEnabled);
+            }
+        } catch (RemoteException ex) {
+            Log.e(TAG, "setAlwaysReportSignalStrength RemoteException", ex);
+            ex.rethrowAsRuntimeException();
+        }
+    }
+
     /**
      * Get the most recently available signal strength information.
      *
diff --git a/telephony/java/com/android/internal/telephony/ITelephony.aidl b/telephony/java/com/android/internal/telephony/ITelephony.aidl
index dfb4ee50f7cc1..99b71e84c77a0 100644
--- a/telephony/java/com/android/internal/telephony/ITelephony.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephony.aidl
@@ -994,6 +994,11 @@ interface ITelephony {
      */
      boolean isManualNetworkSelectionAllowed(int subId);
 
+    /**
+     * Enable or disable always reporting signal strength changes from radio.
+     */
+     void setAlwaysReportSignalStrength(int subId, boolean isEnable);
+
     /**
      * Get P-CSCF address from PCO after data connection is established or modified.
      * @param apnType the apnType, "ims" for IMS APN, "emergency" for EMERGENCY APN