diff --git a/telecomm/java/android/telecom/CallDiagnosticService.java b/telecomm/java/android/telecom/CallDiagnosticService.java
index 5fb6b33..f5357b1 100644
--- a/telecomm/java/android/telecom/CallDiagnosticService.java
+++ b/telecomm/java/android/telecom/CallDiagnosticService.java
@@ -27,8 +27,6 @@
 import android.os.HandlerExecutor;
 import android.os.IBinder;
 import android.os.RemoteException;
-import android.telephony.Annotation;
-import android.telephony.ims.ImsReasonInfo;
 import android.util.ArrayMap;
 
 import com.android.internal.telecom.ICallDiagnosticService;
@@ -59,7 +57,7 @@
  * </pre>
  * <p>
  * <h2>Threading Model</h2>
- * By default, all incoming IPC from Telecom in this service and in the {@link DiagnosticCall}
+ * By default, all incoming IPC from Telecom in this service and in the {@link CallDiagnostics}
  * instances will take place on the main thread.  You can override {@link #getExecutor()} in your
  * implementation to provide your own {@link Executor}.
  * @hide
@@ -116,26 +114,28 @@
     }
 
     /**
-     * Listens to events raised by a {@link DiagnosticCall}.
+     * Listens to events raised by a {@link CallDiagnostics}.
      */
-    private android.telecom.DiagnosticCall.Listener mDiagnosticCallListener =
-            new android.telecom.DiagnosticCall.Listener() {
+    private CallDiagnostics.Listener mDiagnosticCallListener =
+            new CallDiagnostics.Listener() {
 
                 @Override
-                public void onSendDeviceToDeviceMessage(DiagnosticCall diagnosticCall,
-                        @DiagnosticCall.MessageType int message, int value) {
-                    handleSendDeviceToDeviceMessage(diagnosticCall, message, value);
+                public void onSendDeviceToDeviceMessage(CallDiagnostics callDiagnostics,
+                        @CallDiagnostics.MessageType int message, int value) {
+                    handleSendDeviceToDeviceMessage(callDiagnostics, message, value);
                 }
 
                 @Override
-                public void onDisplayDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId,
+                public void onDisplayDiagnosticMessage(CallDiagnostics callDiagnostics,
+                        int messageId,
                         CharSequence message) {
-                    handleDisplayDiagnosticMessage(diagnosticCall, messageId, message);
+                    handleDisplayDiagnosticMessage(callDiagnostics, messageId, message);
                 }
 
                 @Override
-                public void onClearDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId) {
-                    handleClearDiagnosticMessage(diagnosticCall, messageId);
+                public void onClearDiagnosticMessage(CallDiagnostics callDiagnostics,
+                        int messageId) {
+                    handleClearDiagnosticMessage(callDiagnostics, messageId);
                 }
             };
 
@@ -149,7 +149,7 @@
      * Map which tracks the Telecom calls received from the Telecom stack.
      */
     private final Map<String, Call.Details> mCallByTelecomCallId = new ArrayMap<>();
-    private final Map<String, DiagnosticCall> mDiagnosticCallByTelecomCallId = new ArrayMap<>();
+    private final Map<String, CallDiagnostics> mDiagnosticCallByTelecomCallId = new ArrayMap<>();
     private final Object mLock = new Object();
     private ICallDiagnosticServiceAdapter mAdapter;
 
@@ -177,7 +177,7 @@
      * executor you want to use for incoming IPC.
      *
      * @return the {@link Executor} to use for incoming IPC from Telecom to
-     * {@link CallDiagnosticService} and {@link DiagnosticCall}.
+     * {@link CallDiagnosticService} and {@link CallDiagnostics}.
      */
     @SuppressLint("OnNameExpected")
     @NonNull public Executor getExecutor() {
@@ -188,30 +188,30 @@
      * Telecom calls this method on the {@link CallDiagnosticService} with details about a new call
      * which was added to Telecom.
      * <p>
-     * The {@link CallDiagnosticService} returns an implementation of {@link DiagnosticCall} to be
+     * The {@link CallDiagnosticService} returns an implementation of {@link CallDiagnostics} to be
      * used for the lifespan of this call.
      * <p>
      * Calls to this method will use the {@link CallDiagnosticService}'s {@link Executor}; see
      * {@link CallDiagnosticService#getExecutor()} for more information.
      *
      * @param call The details of the new call.
-     * @return An instance of {@link DiagnosticCall} which the {@link CallDiagnosticService}
+     * @return An instance of {@link CallDiagnostics} which the {@link CallDiagnosticService}
      * provides to be used for the lifespan of the call.
-     * @throws IllegalArgumentException if a {@code null} {@link DiagnosticCall} is returned.
+     * @throws IllegalArgumentException if a {@code null} {@link CallDiagnostics} is returned.
      */
-    public abstract @NonNull DiagnosticCall onInitializeDiagnosticCall(@NonNull
+    public abstract @NonNull CallDiagnostics onInitializeCallDiagnostics(@NonNull
             android.telecom.Call.Details call);
 
     /**
-     * Telecom calls this method when a previous created {@link DiagnosticCall} is no longer needed.
-     * This happens when Telecom is no longer tracking the call in question.
+     * Telecom calls this method when a previous created {@link CallDiagnostics} is no longer
+     * needed.  This happens when Telecom is no longer tracking the call in question.
      * <p>
      * Calls to this method will use the {@link CallDiagnosticService}'s {@link Executor}; see
      * {@link CallDiagnosticService#getExecutor()} for more information.
      *
      * @param call The diagnostic call which is no longer tracked by Telecom.
      */
-    public abstract void onRemoveDiagnosticCall(@NonNull DiagnosticCall call);
+    public abstract void onRemoveCallDiagnostics(@NonNull CallDiagnostics call);
 
     /**
      * Telecom calls this method when the audio routing or available audio route information
@@ -260,35 +260,35 @@
         }
 
         getExecutor().execute(() -> {
-            DiagnosticCall diagnosticCall = onInitializeDiagnosticCall(newCallDetails);
-            if (diagnosticCall == null) {
+            CallDiagnostics callDiagnostics = onInitializeCallDiagnostics(newCallDetails);
+            if (callDiagnostics == null) {
                 throw new IllegalArgumentException(
                         "A valid DiagnosticCall instance was not provided.");
             }
             synchronized (mLock) {
-                diagnosticCall.setListener(mDiagnosticCallListener);
-                diagnosticCall.setCallId(telecomCallId);
-                mDiagnosticCallByTelecomCallId.put(telecomCallId, diagnosticCall);
+                callDiagnostics.setListener(mDiagnosticCallListener);
+                callDiagnostics.setCallId(telecomCallId);
+                mDiagnosticCallByTelecomCallId.put(telecomCallId, callDiagnostics);
             }
         });
     }
 
     /**
      * Handles an update to {@link Call.Details} notified by Telecom.
-     * Caches the call details and notifies the {@link DiagnosticCall} of the change via
-     * {@link DiagnosticCall#onCallDetailsChanged(Call.Details)}.
+     * Caches the call details and notifies the {@link CallDiagnostics} of the change via
+     * {@link CallDiagnostics#onCallDetailsChanged(Call.Details)}.
      * @param parcelableCall the new parceled call details from Telecom.
      */
     private void handleCallUpdated(@NonNull ParcelableCall parcelableCall) {
         String telecomCallId = parcelableCall.getId();
         Log.i(this, "handleCallUpdated: callId=%s - updated", telecomCallId);
         Call.Details newCallDetails = Call.Details.createFromParcelableCall(parcelableCall);
-        DiagnosticCall diagnosticCall;
+        CallDiagnostics callDiagnostics;
         synchronized (mLock) {
-            diagnosticCall = mDiagnosticCallByTelecomCallId.get(telecomCallId);
+            callDiagnostics = mDiagnosticCallByTelecomCallId.get(telecomCallId);
             mCallByTelecomCallId.put(telecomCallId, newCallDetails);
         }
-        getExecutor().execute(() -> diagnosticCall.handleCallUpdated(newCallDetails));
+        getExecutor().execute(() -> callDiagnostics.handleCallUpdated(newCallDetails));
     }
 
     /**
@@ -302,37 +302,37 @@
             mCallByTelecomCallId.remove(telecomCallId);
         }
 
-        DiagnosticCall diagnosticCall;
+        CallDiagnostics callDiagnostics;
         synchronized (mLock) {
             if (mDiagnosticCallByTelecomCallId.containsKey(telecomCallId)) {
-                diagnosticCall = mDiagnosticCallByTelecomCallId.remove(telecomCallId);
+                callDiagnostics = mDiagnosticCallByTelecomCallId.remove(telecomCallId);
             } else {
-                diagnosticCall = null;
+                callDiagnostics = null;
             }
         }
 
         // Inform the service of the removed call.
-        if (diagnosticCall != null) {
-            getExecutor().execute(() -> onRemoveDiagnosticCall(diagnosticCall));
+        if (callDiagnostics != null) {
+            getExecutor().execute(() -> onRemoveCallDiagnostics(callDiagnostics));
         }
     }
 
     /**
      * Handles an incoming device to device message received from Telecom.  Notifies the
-     * {@link DiagnosticCall} via {@link DiagnosticCall#onReceiveDeviceToDeviceMessage(int, int)}.
+     * {@link CallDiagnostics} via {@link CallDiagnostics#onReceiveDeviceToDeviceMessage(int, int)}.
      * @param callId
      * @param message
      * @param value
      */
     private void handleReceivedD2DMessage(@NonNull String callId, int message, int value) {
         Log.i(this, "handleReceivedD2DMessage: callId=%s, msg=%d/%d", callId, message, value);
-        DiagnosticCall diagnosticCall;
+        CallDiagnostics callDiagnostics;
         synchronized (mLock) {
-            diagnosticCall = mDiagnosticCallByTelecomCallId.get(callId);
+            callDiagnostics = mDiagnosticCallByTelecomCallId.get(callId);
         }
-        if (diagnosticCall != null) {
+        if (callDiagnostics != null) {
             getExecutor().execute(
-                    () -> diagnosticCall.onReceiveDeviceToDeviceMessage(message, value));
+                    () -> callDiagnostics.onReceiveDeviceToDeviceMessage(message, value));
         }
     }
 
@@ -345,12 +345,12 @@
     private void handleCallDisconnected(@NonNull String callId,
             @NonNull DisconnectCause disconnectCause) {
         Log.i(this, "handleCallDisconnected: call=%s; cause=%s", callId, disconnectCause);
-        DiagnosticCall diagnosticCall = mDiagnosticCallByTelecomCallId.get(callId);
+        CallDiagnostics callDiagnostics = mDiagnosticCallByTelecomCallId.get(callId);
         CharSequence message;
         if (disconnectCause.getImsReasonInfo() != null) {
-            message = diagnosticCall.onCallDisconnected(disconnectCause.getImsReasonInfo());
+            message = callDiagnostics.onCallDisconnected(disconnectCause.getImsReasonInfo());
         } else {
-            message = diagnosticCall.onCallDisconnected(
+            message = callDiagnostics.onCallDisconnected(
                     disconnectCause.getTelephonyDisconnectCause(),
                     disconnectCause.getTelephonyPreciseDisconnectCause());
         }
@@ -375,15 +375,15 @@
     }
 
     /**
-     * Handles a request from a {@link DiagnosticCall} to send a device to device message (received
-     * via {@link DiagnosticCall#sendDeviceToDeviceMessage(int, int)}.
-     * @param diagnosticCall
+     * Handles a request from a {@link CallDiagnostics} to send a device to device message (received
+     * via {@link CallDiagnostics#sendDeviceToDeviceMessage(int, int)}.
+     * @param callDiagnostics
      * @param message
      * @param value
      */
-    private void handleSendDeviceToDeviceMessage(@NonNull DiagnosticCall diagnosticCall,
+    private void handleSendDeviceToDeviceMessage(@NonNull CallDiagnostics callDiagnostics,
             int message, int value) {
-        String callId = diagnosticCall.getCallId();
+        String callId = callDiagnostics.getCallId();
         try {
             mAdapter.sendDeviceToDeviceMessage(callId, message, value);
             Log.i(this, "handleSendDeviceToDeviceMessage: call=%s; msg=%d/%d", callId, message,
@@ -395,15 +395,15 @@
     }
 
     /**
-     * Handles a request from a {@link DiagnosticCall} to display an in-call diagnostic message.
-     * Originates from {@link DiagnosticCall#displayDiagnosticMessage(int, CharSequence)}.
-     * @param diagnosticCall
+     * Handles a request from a {@link CallDiagnostics} to display an in-call diagnostic message.
+     * Originates from {@link CallDiagnostics#displayDiagnosticMessage(int, CharSequence)}.
+     * @param callDiagnostics
      * @param messageId
      * @param message
      */
-    private void handleDisplayDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId,
+    private void handleDisplayDiagnosticMessage(CallDiagnostics callDiagnostics, int messageId,
             CharSequence message) {
-        String callId = diagnosticCall.getCallId();
+        String callId = callDiagnostics.getCallId();
         try {
             mAdapter.displayDiagnosticMessage(callId, messageId, message);
             Log.i(this, "handleDisplayDiagnosticMessage: call=%s; msg=%d/%s", callId, messageId,
@@ -415,14 +415,14 @@
     }
 
     /**
-     * Handles a request from a {@link DiagnosticCall} to clear a previously shown diagnostic
+     * Handles a request from a {@link CallDiagnostics} to clear a previously shown diagnostic
      * message.
-     * Originates from {@link DiagnosticCall#clearDiagnosticMessage(int)}.
-     * @param diagnosticCall
+     * Originates from {@link CallDiagnostics#clearDiagnosticMessage(int)}.
+     * @param callDiagnostics
      * @param messageId
      */
-    private void handleClearDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId) {
-        String callId = diagnosticCall.getCallId();
+    private void handleClearDiagnosticMessage(CallDiagnostics callDiagnostics, int messageId) {
+        String callId = callDiagnostics.getCallId();
         try {
             mAdapter.clearDiagnosticMessage(callId, messageId);
             Log.i(this, "handleClearDiagnosticMessage: call=%s; msg=%d", callId, messageId);
diff --git a/telecomm/java/android/telecom/CallDiagnostics.java b/telecomm/java/android/telecom/CallDiagnostics.java
new file mode 100644
index 0000000..3356431
--- /dev/null
+++ b/telecomm/java/android/telecom/CallDiagnostics.java
@@ -0,0 +1,374 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.telecom;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SystemApi;
+import android.telephony.Annotation;
+import android.telephony.CallQuality;
+import android.telephony.ims.ImsReasonInfo;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.concurrent.Executor;
+
+/**
+ * {@link CallDiagnostics} provides a way for a {@link CallDiagnosticService} to receive diagnostic
+ * information about a mobile call on the device.  A {@link CallDiagnostics} instance is similar to
+ * a {@link Call}, however it does not expose call control capabilities and exposes extra diagnostic
+ * and messaging capabilities not present on a {@link Call}.  The {@link CallDiagnosticService}
+ * creates a {@link CallDiagnostics} for each {@link Call} on the device.  This means that for each
+ * in progress call on the device, the {@link CallDiagnosticService} will create an instance of
+ * {@link CallDiagnostics}.
+ * <p>
+ * The {@link CallDiagnosticService} can generate mid-call diagnostic messages using the
+ * {@link #displayDiagnosticMessage(int, CharSequence)} API which provides the user with valuable
+ * information about conditions impacting their call and corrective actions.  For example, if the
+ * {@link CallDiagnosticService} determines that conditions on the call are degrading, it can inform
+ * the user that the call may soon drop and that they can try using a different calling method
+ * (e.g. VOIP or WIFI).
+ * <h2>Threading Model</h2>
+ * All incoming IPC from Telecom in this class will use the same {@link Executor} as the
+ * {@link CallDiagnosticService}. See {@link CallDiagnosticService#setExecutor(Executor)} for more
+ * information.
+ * @hide
+ */
+@SystemApi
+public abstract class CallDiagnostics {
+
+    /**
+     * @hide
+     */
+    public interface Listener {
+        /**
+         * Used to inform the {@link CallDiagnosticService} of a request to send a D2d message
+         * @param callDiagnostics the call the message is from.
+         * @param message the message type
+         * @param value the message value
+         */
+        void onSendDeviceToDeviceMessage(CallDiagnostics callDiagnostics, int message, int value);
+
+        /**
+         * Used to inform the {@link CallDiagnosticService} of a request to display a diagnostic
+         * message.
+         * @param callDiagnostics the call the message pertains to.
+         * @param messageId an identifier for the message.
+         * @param message the message to display.
+         */
+        void onDisplayDiagnosticMessage(CallDiagnostics callDiagnostics, int messageId,
+                CharSequence message);
+
+        /**
+         * Used to inform the {@link CallDiagnosticService} that a previously shown message is no
+         * longer pertinent.
+         * @param callDiagnostics the call the message pertains to.
+         * @param messageId the ID of the previously posted message.
+         */
+        void onClearDiagnosticMessage(CallDiagnostics callDiagnostics, int messageId);
+    }
+
+    /**
+     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
+     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the radio access type
+     * used for the current call.  The call network type communicated here is an intentional
+     * simplification of the {@link android.telephony.TelephonyManager#getNetworkType(int)} which
+     * removes some of the resolution inherent in those values; the
+     * {@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE_CA} value, for example is
+     * collapsed into the {@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE} value for
+     * efficiency of transport.  For a discussion on the necessity of this simplification, see
+     * {@link #sendDeviceToDeviceMessage(int, int)}.
+     * <p>
+     * Valid values are below:
+     * <UL>
+     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE}</LI>
+     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_IWLAN}</LI>
+     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_NR}</LI>
+     * </UL>
+     */
+    public static final int MESSAGE_CALL_NETWORK_TYPE = 1;
+
+    /**
+     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
+     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the call audio codec
+     * used for the current call.
+     * <p>
+     * The audio codec communicated here is an intentional simplification of the
+     * {@link Connection#EXTRA_AUDIO_CODEC} for a call and focuses on communicating the most common
+     * variants of these audio codecs.  Other variants of these codecs are reported as the next
+     * closest variant.  For example, the {@link Connection#AUDIO_CODEC_EVS_FB} full band codec
+     * is reported via device to device communication as {@link Connection#AUDIO_CODEC_EVS_WB}.
+     * For a discussion on the necessity of this simplification, see
+     * {@link #sendDeviceToDeviceMessage(int, int)}.
+     * <p>
+     * Valid values:
+     * <UL>
+     *     <LI>{@link Connection#AUDIO_CODEC_EVS_WB}</LI>
+     *     <LI>{@link Connection#AUDIO_CODEC_AMR_WB}</LI>
+     *     <LI>{@link Connection#AUDIO_CODEC_AMR}</LI>
+     * </UL>
+     */
+    public static final int MESSAGE_CALL_AUDIO_CODEC = 2;
+
+    /**
+     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
+     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the battery state of
+     * the device.  Will typically mirror battery state reported via intents such as
+     * {@link android.content.Intent#ACTION_BATTERY_LOW}.
+     * <p>
+     * Valid values:
+     * <UL>
+     *     <LI>{@link #BATTERY_STATE_LOW}</LI>
+     *     <LI>{@link #BATTERY_STATE_GOOD}</LI>
+     *     <LI>{@link #BATTERY_STATE_CHARGING}</LI>
+     * </UL>
+     */
+    public static final int MESSAGE_DEVICE_BATTERY_STATE = 3;
+
+    /**
+     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
+     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the overall network
+     * coverage as it pertains to the current call.  A {@link CallDiagnosticService} should signal
+     * poor coverage if the network coverage reaches a level where there is a high probability of
+     * the call dropping as a result.
+     * <p>
+     * Valid values:
+     * <UL>
+     *     <LI>{@link #COVERAGE_POOR}</LI>
+     *     <LI>{@link #COVERAGE_GOOD}</LI>
+     * </UL>
+     */
+    public static final int MESSAGE_DEVICE_NETWORK_COVERAGE = 4;
+
+    /**@hide*/
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = "MESSAGE_", value = {
+            MESSAGE_CALL_NETWORK_TYPE,
+            MESSAGE_CALL_AUDIO_CODEC,
+            MESSAGE_DEVICE_BATTERY_STATE,
+            MESSAGE_DEVICE_NETWORK_COVERAGE
+    })
+    public @interface MessageType {}
+
+    /**
+     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is low.
+     */
+    public static final int BATTERY_STATE_LOW = 1;
+
+    /**
+     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is not low.
+     */
+    public static final int BATTERY_STATE_GOOD = 2;
+
+    /**
+     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is charging.
+     */
+    public static final int BATTERY_STATE_CHARGING = 3;
+
+    /**
+     * Used with {@link #MESSAGE_DEVICE_NETWORK_COVERAGE} to indicate that the coverage is poor.
+     */
+    public static final int COVERAGE_POOR = 1;
+
+    /**
+     * Used with {@link #MESSAGE_DEVICE_NETWORK_COVERAGE} to indicate that the coverage is good.
+     */
+    public static final int COVERAGE_GOOD = 2;
+
+    private Listener mListener;
+    private String mCallId;
+
+    /**
+     * @hide
+     */
+    public void setListener(@NonNull Listener listener) {
+        mListener = listener;
+    }
+
+    /**
+     * Sets the call ID for this {@link CallDiagnostics}.
+     * @param callId
+     * @hide
+     */
+    public void setCallId(@NonNull String callId) {
+        mCallId = callId;
+    }
+
+    /**
+     * @return the Telecom call ID for this {@link CallDiagnostics}.
+     * @hide
+     */
+    public @NonNull String getCallId() {
+        return mCallId;
+    }
+
+    /**
+     * Telecom calls this method when the details of a call changes.
+     * <p>
+     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
+     * see {@link CallDiagnosticService#getExecutor()} for more information.
+     */
+    public abstract void onCallDetailsChanged(@NonNull android.telecom.Call.Details details);
+
+    /**
+     * The {@link CallDiagnosticService} implements this method to handle messages received via
+     * device to device communication.
+     * <p>
+     * See {@link #sendDeviceToDeviceMessage(int, int)} for background on device to device
+     * communication.
+     * <p>
+     * The underlying device to device communication protocol assumes that where there the two
+     * devices communicating are using a different version of the protocol, messages the recipient
+     * are not aware of are silently discarded.  This means an older client talking to a new client
+     * will not receive newer messages and values sent by the new client.
+     * <p>
+     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
+     * see {@link CallDiagnosticService#getExecutor()} for more information.
+     */
+    public abstract void onReceiveDeviceToDeviceMessage(
+            @MessageType int message,
+            int value);
+
+    /**
+     * Sends a device to device message to the device on the other end of this call.
+     * <p>
+     * Device to device communication is an Android platform feature which supports low bandwidth
+     * communication between Android devices while they are in a call.  The device to device
+     * communication leverages DTMF tones or RTP header extensions to pass messages.  The
+     * messages are unacknowledged and sent in a best-effort manner.  The protocols assume that the
+     * nature of the message are informational only and are used only to convey basic state
+     * information between devices.
+     * <p>
+     * Device to device messages are intentional simplifications of more rich indicators in the
+     * platform due to the extreme bandwidth constraints inherent with underlying device to device
+     * communication transports used by the telephony framework.  Device to device communication is
+     * either accomplished by adding RFC8285 compliant RTP header extensions to the audio packets
+     * for a call, or using the DTMF digits A-D as a communication pathway.  RTP header extension
+     * packets ride alongside a the audio for a call, and are thus limited to roughly a byte for
+     * a message.  Signalling requirements for DTMF digits place even more significant limitations
+     * on the amount of information which can be communicated during a call, offering only a few
+     * bits of potential information per message.  The messages and values are constrained in order
+     * to meet the limited bandwidth inherent with DTMF signalling.
+     * <p>
+     * Allowed message types are:
+     * <ul>
+     *     <li>{@link #MESSAGE_CALL_NETWORK_TYPE}</LI>
+     *     <li>{@link #MESSAGE_CALL_AUDIO_CODEC}</LI>
+     *     <li>{@link #MESSAGE_DEVICE_BATTERY_STATE}</LI>
+     *     <li>{@link #MESSAGE_DEVICE_NETWORK_COVERAGE}</LI>
+     * </ul>
+     * @param message The message type to send.
+     * @param value The message value corresponding to the type.
+     */
+    public final void sendDeviceToDeviceMessage(int message, int value) {
+        if (mListener != null) {
+            mListener.onSendDeviceToDeviceMessage(this, message, value);
+        }
+    }
+
+    /**
+     * Telecom calls this method when a GSM or CDMA call disconnects.
+     * The CallDiagnosticService can return a human readable disconnect message which will be passed
+     * to the Dialer app as the {@link DisconnectCause#getDescription()}.  A dialer app typically
+     * shows this message at the termination of the call.  If {@code null} is returned, the
+     * disconnect message generated by the telephony stack will be shown instead.
+     * <p>
+     * @param disconnectCause the disconnect cause for the call.
+     * @param preciseDisconnectCause the precise disconnect cause for the call.
+     * @return the disconnect message to use in place of the default Telephony message, or
+     * {@code null} if the default message will not be overridden.
+     * <p>
+     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
+     * see {@link CallDiagnosticService#getExecutor()} for more information.
+     */
+    // TODO: Wire in Telephony support for this.
+    public abstract @Nullable CharSequence onCallDisconnected(
+            @Annotation.DisconnectCauses int disconnectCause,
+            @Annotation.PreciseDisconnectCauses int preciseDisconnectCause);
+
+    /**
+     * Telecom calls this method when an IMS call disconnects and Telephony has already
+     * provided the disconnect reason info and disconnect message for the call.  The
+     * {@link CallDiagnosticService} can intercept the raw IMS disconnect reason at this point and
+     * combine it with other call diagnostic information it is aware of to override the disconnect
+     * call message if desired.
+     *
+     * @param disconnectReason The {@link ImsReasonInfo} associated with the call disconnection.
+     * @return A user-readable call disconnect message to use in place of the platform-generated
+     * disconnect message, or {@code null} if the disconnect message should not be overridden.
+     * <p>
+     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
+     * see {@link CallDiagnosticService#getExecutor()} for more information.
+     */
+    // TODO: Wire in Telephony support for this.
+    public abstract @Nullable CharSequence onCallDisconnected(
+            @NonNull ImsReasonInfo disconnectReason);
+
+    /**
+     * Telecom calls this method when a {@link CallQuality} report is received from the telephony
+     * stack for a call.
+     * @param callQuality The call quality report for this call.
+     * <p>
+     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
+     * see {@link CallDiagnosticService#getExecutor()} for more information.
+     */
+    public abstract void onCallQualityReceived(@NonNull CallQuality callQuality);
+
+     /**
+      * Signals the active default dialer app to display a call diagnostic message.  This can be
+      * used to report problems encountered during the span of a call.
+      * <p>
+      * The {@link CallDiagnosticService} provides a unique client-specific identifier used to
+      * identify the specific diagnostic message type.
+      * <p>
+      * The {@link CallDiagnosticService} should call {@link #clearDiagnosticMessage(int)} when the
+      * diagnostic condition has cleared.
+      * @param messageId the unique message identifier.
+      * @param message a human-readable, localized message to be shown to the user indicating a
+      *                call issue which has occurred, along with potential mitigating actions.
+     */
+    public final void displayDiagnosticMessage(int messageId, @NonNull
+            CharSequence message) {
+        if (mListener != null) {
+            mListener.onDisplayDiagnosticMessage(this, messageId, message);
+        }
+    }
+
+    /**
+     * Signals to the active default dialer that the diagnostic message previously signalled using
+     * {@link #displayDiagnosticMessage(int, CharSequence)} with the specified messageId is no
+     * longer applicable (e.g. service has improved, for example.
+     * @param messageId the message identifier for a message previously shown via
+     *                  {@link #displayDiagnosticMessage(int, CharSequence)}.
+     */
+    public final void clearDiagnosticMessage(int messageId) {
+        if (mListener != null) {
+            mListener.onClearDiagnosticMessage(this, messageId);
+        }
+    }
+
+    /**
+     * Called by the {@link CallDiagnosticService} to update the call details for this
+     * {@link CallDiagnostics} based on an update received from Telecom.
+     * @param newDetails the new call details.
+     * @hide
+     */
+    public void handleCallUpdated(@NonNull Call.Details newDetails) {
+        onCallDetailsChanged(newDetails);
+    }
+}
diff --git a/telecomm/java/android/telecom/Connection.java b/telecomm/java/android/telecom/Connection.java
index 335857af8..6dab6df 100644
--- a/telecomm/java/android/telecom/Connection.java
+++ b/telecomm/java/android/telecom/Connection.java
@@ -947,7 +947,7 @@
      * {@link CallDiagnosticService} implementation which is active.
      * <p>
      * Likewise, if a {@link CallDiagnosticService} sends a message using
-     * {@link DiagnosticCall#sendDeviceToDeviceMessage(int, int)}, it will be routed to telephony
+     * {@link CallDiagnostics#sendDeviceToDeviceMessage(int, int)}, it will be routed to telephony
      * via {@link Connection#onCallEvent(String, Bundle)}.  The telephony stack will relay the
      * message to the other device.
      * @hide
@@ -960,7 +960,7 @@
      * Sent along with {@link #EVENT_DEVICE_TO_DEVICE_MESSAGE} to indicate the device to device
      * message type.
      *
-     * See {@link DiagnosticCall} for more information.
+     * See {@link CallDiagnostics} for more information.
      * @hide
      */
     @SystemApi
@@ -971,7 +971,7 @@
      * Sent along with {@link #EVENT_DEVICE_TO_DEVICE_MESSAGE} to indicate the device to device
      * message value.
      * <p>
-     * See {@link DiagnosticCall} for more information.
+     * See {@link CallDiagnostics} for more information.
      * @hide
      */
     @SystemApi
diff --git a/telecomm/java/android/telecom/DiagnosticCall.java b/telecomm/java/android/telecom/DiagnosticCall.java
index af46b77..a6b7258 100644
--- a/telecomm/java/android/telecom/DiagnosticCall.java
+++ b/telecomm/java/android/telecom/DiagnosticCall.java
@@ -16,338 +16,12 @@
 
 package android.telecom;
 
-import android.annotation.IntDef;
-import android.annotation.NonNull;
-import android.annotation.Nullable;
 import android.annotation.SystemApi;
-import android.telephony.Annotation;
-import android.telephony.CallQuality;
-import android.telephony.ims.ImsReasonInfo;
-
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.util.concurrent.Executor;
 
 /**
- * A {@link DiagnosticCall} provides a way for a {@link CallDiagnosticService} to receive diagnostic
- * information about a mobile call on the device.  A {@link DiagnosticCall} is similar to a
- * {@link Call}, however it does not expose call control capabilities and exposes extra diagnostic
- * and messaging capabilities not present on a {@link Call}.  The {@link CallDiagnosticService}
- * creates a {@link DiagnosticCall} for each {@link Call} on the device.  This means that for each
- * in progress call on the device, the {@link CallDiagnosticService} will create an instance of
- * {@link DiagnosticCall}.
- * <p>
- * The {@link CallDiagnosticService} can generate mid-call diagnostic messages using the
- * {@link #displayDiagnosticMessage(int, CharSequence)} API which provides the user with valuable
- * information about conditions impacting their call and corrective actions.  For example, if the
- * {@link CallDiagnosticService} determines that conditions on the call are degrading, it can inform
- * the user that the call may soon drop and that they can try using a different calling method
- * (e.g. VOIP or WIFI).
- * <h2>Threading Model</h2>
- * All incoming IPC from Telecom in this class will use the same {@link Executor} as the
- * {@link CallDiagnosticService}. See {@link CallDiagnosticService#setExecutor(Executor)} for more
- * information.
+ * @deprecated use {@link CallDiagnostics} instead.
  * @hide
  */
 @SystemApi
-public abstract class DiagnosticCall {
-
-    /**
-     * @hide
-     */
-    public interface Listener {
-        void onSendDeviceToDeviceMessage(DiagnosticCall diagnosticCall, int message, int value);
-        void onDisplayDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId,
-                CharSequence message);
-        void onClearDiagnosticMessage(DiagnosticCall diagnosticCall, int messageId);
-    }
-
-    /**
-     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
-     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the radio access type
-     * used for the current call.  The call network type communicated here is an intentional
-     * simplification of the {@link android.telephony.TelephonyManager#getNetworkType(int)} which
-     * removes some of the resolution inherent in those values; the
-     * {@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE_CA} value, for example is
-     * collapsed into the {@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE} value for
-     * efficiency of transport.  For a discussion on the necessity of this simplification, see
-     * {@link #sendDeviceToDeviceMessage(int, int)}.
-     * <p>
-     * Valid values are below:
-     * <UL>
-     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_LTE}</LI>
-     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_IWLAN}</LI>
-     *     <LI>{@link android.telephony.TelephonyManager#NETWORK_TYPE_NR}</LI>
-     * </UL>
-     */
-    public static final int MESSAGE_CALL_NETWORK_TYPE = 1;
-
-    /**
-     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
-     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the call audio codec
-     * used for the current call.
-     * <p>
-     * The audio codec communicated here is an intentional simplification of the
-     * {@link Connection#EXTRA_AUDIO_CODEC} for a call and focuses on communicating the most common
-     * variants of these audio codecs.  Other variants of these codecs are reported as the next
-     * closest variant.  For example, the {@link Connection#AUDIO_CODEC_EVS_FB} full band codec
-     * is reported via device to device communication as {@link Connection#AUDIO_CODEC_EVS_WB}.
-     * For a discussion on the necessity of this simplification, see
-     * {@link #sendDeviceToDeviceMessage(int, int)}.
-     * <p>
-     * Valid values:
-     * <UL>
-     *     <LI>{@link Connection#AUDIO_CODEC_EVS_WB}</LI>
-     *     <LI>{@link Connection#AUDIO_CODEC_AMR_WB}</LI>
-     *     <LI>{@link Connection#AUDIO_CODEC_AMR}</LI>
-     * </UL>
-     */
-    public static final int MESSAGE_CALL_AUDIO_CODEC = 2;
-
-    /**
-     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
-     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the battery state of
-     * the device.  Will typically mirror battery state reported via intents such as
-     * {@link android.content.Intent#ACTION_BATTERY_LOW}.
-     * <p>
-     * Valid values:
-     * <UL>
-     *     <LI>{@link #BATTERY_STATE_LOW}</LI>
-     *     <LI>{@link #BATTERY_STATE_GOOD}</LI>
-     *     <LI>{@link #BATTERY_STATE_CHARGING}</LI>
-     * </UL>
-     */
-    public static final int MESSAGE_DEVICE_BATTERY_STATE = 3;
-
-    /**
-     * Device to device message sent via {@link #sendDeviceToDeviceMessage(int, int)} (received via
-     * {@link #onReceiveDeviceToDeviceMessage(int, int)}) which communicates the overall network
-     * coverage as it pertains to the current call.  A {@link CallDiagnosticService} should signal
-     * poor coverage if the network coverage reaches a level where there is a high probability of
-     * the call dropping as a result.
-     * <p>
-     * Valid values:
-     * <UL>
-     *     <LI>{@link #COVERAGE_POOR}</LI>
-     *     <LI>{@link #COVERAGE_GOOD}</LI>
-     * </UL>
-     */
-    public static final int MESSAGE_DEVICE_NETWORK_COVERAGE = 4;
-
-    /**@hide*/
-    @Retention(RetentionPolicy.SOURCE)
-    @IntDef(prefix = "MESSAGE_", value = {
-            MESSAGE_CALL_NETWORK_TYPE,
-            MESSAGE_CALL_AUDIO_CODEC,
-            MESSAGE_DEVICE_BATTERY_STATE,
-            MESSAGE_DEVICE_NETWORK_COVERAGE
-    })
-    public @interface MessageType {}
-
-    /**
-     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is low.
-     */
-    public static final int BATTERY_STATE_LOW = 1;
-
-    /**
-     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is not low.
-     */
-    public static final int BATTERY_STATE_GOOD = 2;
-
-    /**
-     * Used with {@link #MESSAGE_DEVICE_BATTERY_STATE} to indicate that the battery is charging.
-     */
-    public static final int BATTERY_STATE_CHARGING = 3;
-
-    /**
-     * Used with {@link #MESSAGE_DEVICE_NETWORK_COVERAGE} to indicate that the coverage is poor.
-     */
-    public static final int COVERAGE_POOR = 1;
-
-    /**
-     * Used with {@link #MESSAGE_DEVICE_NETWORK_COVERAGE} to indicate that the coverage is good.
-     */
-    public static final int COVERAGE_GOOD = 2;
-
-    private Listener mListener;
-    private String mCallId;
-
-    /**
-     * @hide
-     */
-    public void setListener(@NonNull Listener listener) {
-        mListener = listener;
-    }
-
-    /**
-     * Sets the call ID for this {@link DiagnosticCall}.
-     * @param callId
-     * @hide
-     */
-    public void setCallId(@NonNull String callId) {
-        mCallId = callId;
-    }
-
-    /**
-     * @return the Telecom call ID for this {@link DiagnosticCall}.
-     * @hide
-     */
-    public @NonNull String getCallId() {
-        return mCallId;
-    }
-
-    /**
-     * Telecom calls this method when the details of a call changes.
-     * <p>
-     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
-     * see {@link CallDiagnosticService#getExecutor()} for more information.
-     */
-    public abstract void onCallDetailsChanged(@NonNull android.telecom.Call.Details details);
-
-    /**
-     * The {@link CallDiagnosticService} implements this method to handle messages received via
-     * device to device communication.
-     * <p>
-     * See {@link #sendDeviceToDeviceMessage(int, int)} for background on device to device
-     * communication.
-     * <p>
-     * The underlying device to device communication protocol assumes that where there the two
-     * devices communicating are using a different version of the protocol, messages the recipient
-     * are not aware of are silently discarded.  This means an older client talking to a new client
-     * will not receive newer messages and values sent by the new client.
-     * <p>
-     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
-     * see {@link CallDiagnosticService#getExecutor()} for more information.
-     */
-    public abstract void onReceiveDeviceToDeviceMessage(
-            @MessageType int message,
-            int value);
-
-    /**
-     * Sends a device to device message to the device on the other end of this call.
-     * <p>
-     * Device to device communication is an Android platform feature which supports low bandwidth
-     * communication between Android devices while they are in a call.  The device to device
-     * communication leverages DTMF tones or RTP header extensions to pass messages.  The
-     * messages are unacknowledged and sent in a best-effort manner.  The protocols assume that the
-     * nature of the message are informational only and are used only to convey basic state
-     * information between devices.
-     * <p>
-     * Device to device messages are intentional simplifications of more rich indicators in the
-     * platform due to the extreme bandwidth constraints inherent with underlying device to device
-     * communication transports used by the telephony framework.  Device to device communication is
-     * either accomplished by adding RFC8285 compliant RTP header extensions to the audio packets
-     * for a call, or using the DTMF digits A-D as a communication pathway.  RTP header extension
-     * packets ride alongside a the audio for a call, and are thus limited to roughly a byte for
-     * a message.  Signalling requirements for DTMF digits place even more significant limitations
-     * on the amount of information which can be communicated during a call, offering only a few
-     * bits of potential information per message.  The messages and values are constrained in order
-     * to meet the limited bandwidth inherent with DTMF signalling.
-     * <p>
-     * Allowed message types are:
-     * <ul>
-     *     <li>{@link #MESSAGE_CALL_NETWORK_TYPE}</LI>
-     *     <li>{@link #MESSAGE_CALL_AUDIO_CODEC}</LI>
-     *     <li>{@link #MESSAGE_DEVICE_BATTERY_STATE}</LI>
-     *     <li>{@link #MESSAGE_DEVICE_NETWORK_COVERAGE}</LI>
-     * </ul>
-     * @param message The message type to send.
-     * @param value The message value corresponding to the type.
-     */
-    public final void sendDeviceToDeviceMessage(int message, int value) {
-        if (mListener != null) {
-            mListener.onSendDeviceToDeviceMessage(this, message, value);
-        }
-    }
-
-    /**
-     * Telecom calls this method when a GSM or CDMA call disconnects.
-     * The CallDiagnosticService can return a human readable disconnect message which will be passed
-     * to the Dialer app as the {@link DisconnectCause#getDescription()}.  A dialer app typically
-     * shows this message at the termination of the call.  If {@code null} is returned, the
-     * disconnect message generated by the telephony stack will be shown instead.
-     * <p>
-     * @param disconnectCause the disconnect cause for the call.
-     * @param preciseDisconnectCause the precise disconnect cause for the call.
-     * @return the disconnect message to use in place of the default Telephony message, or
-     * {@code null} if the default message will not be overridden.
-     * <p>
-     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
-     * see {@link CallDiagnosticService#getExecutor()} for more information.
-     */
-    // TODO: Wire in Telephony support for this.
-    public abstract @Nullable CharSequence onCallDisconnected(
-            @Annotation.DisconnectCauses int disconnectCause,
-            @Annotation.PreciseDisconnectCauses int preciseDisconnectCause);
-
-    /**
-     * Telecom calls this method when an IMS call disconnects and Telephony has already
-     * provided the disconnect reason info and disconnect message for the call.  The
-     * {@link CallDiagnosticService} can intercept the raw IMS disconnect reason at this point and
-     * combine it with other call diagnostic information it is aware of to override the disconnect
-     * call message if desired.
-     *
-     * @param disconnectReason The {@link ImsReasonInfo} associated with the call disconnection.
-     * @return A user-readable call disconnect message to use in place of the platform-generated
-     * disconnect message, or {@code null} if the disconnect message should not be overridden.
-     * <p>
-     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
-     * see {@link CallDiagnosticService#getExecutor()} for more information.
-     */
-    // TODO: Wire in Telephony support for this.
-    public abstract @Nullable CharSequence onCallDisconnected(
-            @NonNull ImsReasonInfo disconnectReason);
-
-    /**
-     * Telecom calls this method when a {@link CallQuality} report is received from the telephony
-     * stack for a call.
-     * @param callQuality The call quality report for this call.
-     * <p>
-     * Calls to this method will use the same {@link Executor} as the {@link CallDiagnosticService};
-     * see {@link CallDiagnosticService#getExecutor()} for more information.
-     */
-    public abstract void onCallQualityReceived(@NonNull CallQuality callQuality);
-
-     /**
-      * Signals the active default dialer app to display a call diagnostic message.  This can be
-      * used to report problems encountered during the span of a call.
-      * <p>
-      * The {@link CallDiagnosticService} provides a unique client-specific identifier used to
-      * identify the specific diagnostic message type.
-      * <p>
-      * The {@link CallDiagnosticService} should call {@link #clearDiagnosticMessage(int)} when the
-      * diagnostic condition has cleared.
-      * @param messageId the unique message identifier.
-      * @param message a human-readable, localized message to be shown to the user indicating a
-      *                call issue which has occurred, along with potential mitigating actions.
-     */
-    public final void displayDiagnosticMessage(int messageId, @NonNull
-            CharSequence message) {
-        if (mListener != null) {
-            mListener.onDisplayDiagnosticMessage(this, messageId, message);
-        }
-    }
-
-    /**
-     * Signals to the active default dialer that the diagnostic message previously signalled using
-     * {@link #displayDiagnosticMessage(int, CharSequence)} with the specified messageId is no
-     * longer applicable (e.g. service has improved, for example.
-     * @param messageId the message identifier for a message previously shown via
-     *                  {@link #displayDiagnosticMessage(int, CharSequence)}.
-     */
-    public final void clearDiagnosticMessage(int messageId) {
-        if (mListener != null) {
-            mListener.onClearDiagnosticMessage(this, messageId);
-        }
-    }
-
-    /**
-     * Called by the {@link CallDiagnosticService} to update the call details for this
-     * {@link DiagnosticCall} based on an update received from Telecom.
-     * @param newDetails the new call details.
-     * @hide
-     */
-    public void handleCallUpdated(@NonNull Call.Details newDetails) {
-        onCallDetailsChanged(newDetails);
-    }
+public abstract class DiagnosticCall extends CallDiagnostics {
 }