diff --git a/api/current.txt b/api/current.txt
index 90dfcc83ae097..775491c55cbbb 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -43107,6 +43107,7 @@ package android.telephony {
     field public static final int DATA_CONNECTING = 1; // 0x1
     field public static final int DATA_DISCONNECTED = 0; // 0x0
     field public static final int DATA_SUSPENDED = 3; // 0x3
+    field public static final int DATA_UNKNOWN = -1; // 0xffffffff
     field public static final java.lang.String EXTRA_CALL_VOICEMAIL_INTENT = "android.telephony.extra.CALL_VOICEMAIL_INTENT";
     field public static final java.lang.String EXTRA_CARRIER_ID = "android.telephony.extra.CARRIER_ID";
     field public static final java.lang.String EXTRA_CARRIER_NAME = "android.telephony.extra.CARRIER_NAME";
diff --git a/api/system-current.txt b/api/system-current.txt
index fdb09d639360e..f9c6d50620a88 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -5061,6 +5061,87 @@ package android.telephony {
     field public static final java.lang.String KEY_CARRIER_SETUP_APP_STRING = "carrier_setup_app_string";
   }
 
+  public final class DataFailCause {
+    field public static final int ACTIVATION_REJECT_GGSN = 30; // 0x1e
+    field public static final int ACTIVATION_REJECT_UNSPECIFIED = 31; // 0x1f
+    field public static final int ACTIVE_PDP_CONTEXT_MAX_NUMBER_REACHED = 65; // 0x41
+    field public static final int APN_TYPE_CONFLICT = 112; // 0x70
+    field public static final int AUTH_FAILURE_ON_EMERGENCY_CALL = 122; // 0x7a
+    field public static final int COMPANION_IFACE_IN_USE = 118; // 0x76
+    field public static final int CONDITIONAL_IE_ERROR = 100; // 0x64
+    field public static final int EMERGENCY_IFACE_ONLY = 116; // 0x74
+    field public static final int EMM_ACCESS_BARRED = 115; // 0x73
+    field public static final int EMM_ACCESS_BARRED_INFINITE_RETRY = 121; // 0x79
+    field public static final int ERROR_UNSPECIFIED = 65535; // 0xffff
+    field public static final int ESM_INFO_NOT_RECEIVED = 53; // 0x35
+    field public static final int FEATURE_NOT_SUPP = 40; // 0x28
+    field public static final int FILTER_SEMANTIC_ERROR = 44; // 0x2c
+    field public static final int FILTER_SYTAX_ERROR = 45; // 0x2d
+    field public static final int GPRS_REGISTRATION_FAIL = -2; // 0xfffffffe
+    field public static final int IFACE_AND_POL_FAMILY_MISMATCH = 120; // 0x78
+    field public static final int IFACE_MISMATCH = 117; // 0x75
+    field public static final int INSUFFICIENT_RESOURCES = 26; // 0x1a
+    field public static final int INTERNAL_CALL_PREEMPT_BY_HIGH_PRIO_APN = 114; // 0x72
+    field public static final int INVALID_MANDATORY_INFO = 96; // 0x60
+    field public static final int INVALID_PCSCF_ADDR = 113; // 0x71
+    field public static final int INVALID_TRANSACTION_ID = 81; // 0x51
+    field public static final int IP_ADDRESS_MISMATCH = 119; // 0x77
+    field public static final int LLC_SNDCP = 25; // 0x19
+    field public static final int LOST_CONNECTION = 65540; // 0x10004
+    field public static final int MESSAGE_INCORRECT_SEMANTIC = 95; // 0x5f
+    field public static final int MESSAGE_TYPE_UNSUPPORTED = 97; // 0x61
+    field public static final int MISSING_UNKNOWN_APN = 27; // 0x1b
+    field public static final int MSG_AND_PROTOCOL_STATE_UNCOMPATIBLE = 101; // 0x65
+    field public static final int MSG_TYPE_NONCOMPATIBLE_STATE = 98; // 0x62
+    field public static final int MULTI_CONN_TO_SAME_PDN_NOT_ALLOWED = 55; // 0x37
+    field public static final int NAS_SIGNALLING = 14; // 0xe
+    field public static final int NETWORK_FAILURE = 38; // 0x26
+    field public static final int NONE = 0; // 0x0
+    field public static final int NSAPI_IN_USE = 35; // 0x23
+    field public static final int OEM_DCFAILCAUSE_1 = 4097; // 0x1001
+    field public static final int OEM_DCFAILCAUSE_10 = 4106; // 0x100a
+    field public static final int OEM_DCFAILCAUSE_11 = 4107; // 0x100b
+    field public static final int OEM_DCFAILCAUSE_12 = 4108; // 0x100c
+    field public static final int OEM_DCFAILCAUSE_13 = 4109; // 0x100d
+    field public static final int OEM_DCFAILCAUSE_14 = 4110; // 0x100e
+    field public static final int OEM_DCFAILCAUSE_15 = 4111; // 0x100f
+    field public static final int OEM_DCFAILCAUSE_2 = 4098; // 0x1002
+    field public static final int OEM_DCFAILCAUSE_3 = 4099; // 0x1003
+    field public static final int OEM_DCFAILCAUSE_4 = 4100; // 0x1004
+    field public static final int OEM_DCFAILCAUSE_5 = 4101; // 0x1005
+    field public static final int OEM_DCFAILCAUSE_6 = 4102; // 0x1006
+    field public static final int OEM_DCFAILCAUSE_7 = 4103; // 0x1007
+    field public static final int OEM_DCFAILCAUSE_8 = 4104; // 0x1008
+    field public static final int OEM_DCFAILCAUSE_9 = 4105; // 0x1009
+    field public static final int ONLY_IPV4_ALLOWED = 50; // 0x32
+    field public static final int ONLY_IPV6_ALLOWED = 51; // 0x33
+    field public static final int ONLY_SINGLE_BEARER_ALLOWED = 52; // 0x34
+    field public static final int OPERATOR_BARRED = 8; // 0x8
+    field public static final int PDN_CONN_DOES_NOT_EXIST = 54; // 0x36
+    field public static final int PDP_WITHOUT_ACTIVE_TFT = 46; // 0x2e
+    field public static final int PREF_RADIO_TECH_CHANGED = -4; // 0xfffffffc
+    field public static final int PROTOCOL_ERRORS = 111; // 0x6f
+    field public static final int QOS_NOT_ACCEPTED = 37; // 0x25
+    field public static final int RADIO_NOT_AVAILABLE = 65537; // 0x10001
+    field public static final int RADIO_POWER_OFF = -5; // 0xfffffffb
+    field public static final int REGISTRATION_FAIL = -1; // 0xffffffff
+    field public static final int REGULAR_DEACTIVATION = 36; // 0x24
+    field public static final int SERVICE_OPTION_NOT_SUBSCRIBED = 33; // 0x21
+    field public static final int SERVICE_OPTION_NOT_SUPPORTED = 32; // 0x20
+    field public static final int SERVICE_OPTION_OUT_OF_ORDER = 34; // 0x22
+    field public static final int SIGNAL_LOST = -3; // 0xfffffffd
+    field public static final int TETHERED_CALL_ACTIVE = -6; // 0xfffffffa
+    field public static final int TFT_SEMANTIC_ERROR = 41; // 0x29
+    field public static final int TFT_SYTAX_ERROR = 42; // 0x2a
+    field public static final int UMTS_REACTIVATION_REQ = 39; // 0x27
+    field public static final int UNKNOWN = 65536; // 0x10000
+    field public static final int UNKNOWN_INFO_ELEMENT = 99; // 0x63
+    field public static final int UNKNOWN_PDP_ADDRESS_TYPE = 28; // 0x1c
+    field public static final int UNKNOWN_PDP_CONTEXT = 43; // 0x2b
+    field public static final int UNSUPPORTED_APN_IN_CURRENT_PLMN = 66; // 0x42
+    field public static final int USER_AUTHENTICATION = 29; // 0x1d
+  }
+
   public class DisconnectCause {
     field public static final int ALREADY_DIALING = 72; // 0x48
     field public static final int ANSWERED_ELSEWHERE = 52; // 0x34
@@ -5228,11 +5309,13 @@ package android.telephony {
   public class PhoneStateListener {
     method public void onCallDisconnectCauseChanged(int, int);
     method public void onPreciseCallStateChanged(android.telephony.PreciseCallState);
+    method public void onPreciseDataConnectionStateChanged(android.telephony.PreciseDataConnectionState);
     method public void onRadioPowerStateChanged(int);
     method public void onSrvccStateChanged(int);
     method public void onVoiceActivationStateChanged(int);
     field public static final int LISTEN_CALL_DISCONNECT_CAUSES = 33554432; // 0x2000000
     field public static final int LISTEN_PRECISE_CALL_STATE = 2048; // 0x800
+    field public static final int LISTEN_PRECISE_DATA_CONNECTION_STATE = 4096; // 0x1000
     field public static final int LISTEN_RADIO_POWER_STATE_CHANGED = 8388608; // 0x800000
     field public static final int LISTEN_SRVCC_STATE_CHANGED = 16384; // 0x4000
     field public static final int LISTEN_VOICE_ACTIVATION_STATE = 131072; // 0x20000
@@ -5257,6 +5340,16 @@ package android.telephony {
     field public static final int PRECISE_CALL_STATE_WAITING = 6; // 0x6
   }
 
+  public final class PreciseDataConnectionState implements android.os.Parcelable {
+    method public int describeContents();
+    method public java.lang.String getDataConnectionApn();
+    method public int getDataConnectionApnTypeBitMask();
+    method public int getDataConnectionFailCause();
+    method public int getDataConnectionState();
+    method public void writeToParcel(android.os.Parcel, int);
+    field public static final android.os.Parcelable.Creator<android.telephony.PreciseDataConnectionState> CREATOR;
+  }
+
   public class PreciseDisconnectCause {
     field public static final int ACCESS_CLASS_BLOCKED = 260; // 0x104
     field public static final int ACCESS_INFORMATION_DISCARDED = 43; // 0x2b
diff --git a/services/core/java/com/android/server/TelephonyRegistry.java b/services/core/java/com/android/server/TelephonyRegistry.java
index 6d10632a08cd7..566d837a2ba31 100644
--- a/services/core/java/com/android/server/TelephonyRegistry.java
+++ b/services/core/java/com/android/server/TelephonyRegistry.java
@@ -34,6 +34,7 @@ import android.os.RemoteException;
 import android.os.UserHandle;
 import android.telephony.CellInfo;
 import android.telephony.CellLocation;
+import android.telephony.DataFailCause;
 import android.telephony.DisconnectCause;
 import android.telephony.LocationAccessPolicy;
 import android.telephony.PhoneCapability;
@@ -47,6 +48,7 @@ import android.telephony.ServiceState;
 import android.telephony.SignalStrength;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
+import android.telephony.data.ApnSetting;
 import android.telephony.emergency.EmergencyNumber;
 import android.util.LocalLog;
 import android.util.StatsLog;
@@ -1366,7 +1368,8 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                     mDataConnectionNetworkType[phoneId] = networkType;
                 }
                 mPreciseDataConnectionState = new PreciseDataConnectionState(state, networkType,
-                        apnType, apn, linkProperties, "");
+                        ApnSetting.getApnTypesBitmaskFromString(apnType), apn,
+                        linkProperties, DataFailCause.NONE);
                 for (Record r : mRecords) {
                     if (r.matchPhoneStateListenerEvent(
                             PhoneStateListener.LISTEN_PRECISE_DATA_CONNECTION_STATE)) {
@@ -1384,7 +1387,7 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         broadcastDataConnectionStateChanged(state, isDataAllowed, apn, apnType, linkProperties,
                 networkCapabilities, roaming, subId);
         broadcastPreciseDataConnectionStateChanged(state, networkType, apnType, apn,
-                linkProperties, "");
+                linkProperties, DataFailCause.NONE);
     }
 
     public void notifyDataConnectionFailed(String apnType) {
@@ -1403,7 +1406,8 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         synchronized (mRecords) {
             mPreciseDataConnectionState = new PreciseDataConnectionState(
                     TelephonyManager.DATA_UNKNOWN,TelephonyManager.NETWORK_TYPE_UNKNOWN,
-                    apnType, "", null, "");
+                    ApnSetting.getApnTypesBitmaskFromString(apnType), "", null,
+                    DataFailCause.NONE);
             for (Record r : mRecords) {
                 if (r.matchPhoneStateListenerEvent(
                         PhoneStateListener.LISTEN_PRECISE_DATA_CONNECTION_STATE)) {
@@ -1418,7 +1422,8 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         }
         broadcastDataConnectionFailed(apnType, subId);
         broadcastPreciseDataConnectionStateChanged(TelephonyManager.DATA_UNKNOWN,
-                TelephonyManager.NETWORK_TYPE_UNKNOWN, apnType, "", null, "");
+                TelephonyManager.NETWORK_TYPE_UNKNOWN, apnType, "", null,
+                DataFailCause.NONE);
     }
 
     public void notifyCellLocation(Bundle cellLocation) {
@@ -1528,14 +1533,15 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         }
     }
 
-    public void notifyPreciseDataConnectionFailed(String apnType, String apn, String failCause) {
+    public void notifyPreciseDataConnectionFailed(String apnType,
+            String apn, @DataFailCause.FailCause int failCause) {
         if (!checkNotifyPermission("notifyPreciseDataConnectionFailed()")) {
             return;
         }
         synchronized (mRecords) {
             mPreciseDataConnectionState = new PreciseDataConnectionState(
                     TelephonyManager.DATA_UNKNOWN, TelephonyManager.NETWORK_TYPE_UNKNOWN,
-                    apnType, apn, null, failCause);
+                    ApnSetting.getApnTypesBitmaskFromString(apnType), apn, null, failCause);
             for (Record r : mRecords) {
                 if (r.matchPhoneStateListenerEvent(
                         PhoneStateListener.LISTEN_PRECISE_DATA_CONNECTION_STATE)) {
@@ -1929,9 +1935,8 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
     }
 
     private void broadcastPreciseDataConnectionStateChanged(int state, int networkType,
-                                                            String apnType, String apn,
-                                                            LinkProperties linkProperties,
-                                                            String failCause) {
+            String apnType, String apn, LinkProperties linkProperties,
+            @DataFailCause.FailCause int failCause) {
         Intent intent = new Intent(TelephonyManager.ACTION_PRECISE_DATA_CONNECTION_STATE_CHANGED);
         intent.putExtra(PhoneConstants.STATE_KEY, state);
         intent.putExtra(PhoneConstants.DATA_NETWORK_TYPE_KEY, networkType);
@@ -1940,7 +1945,7 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         if (linkProperties != null) {
             intent.putExtra(PhoneConstants.DATA_LINK_PROPERTIES_KEY, linkProperties);
         }
-        if (failCause != null) intent.putExtra(PhoneConstants.DATA_FAILURE_CAUSE_KEY, failCause);
+        intent.putExtra(PhoneConstants.DATA_FAILURE_CAUSE_KEY, failCause);
 
         mContext.sendBroadcastAsUser(intent, UserHandle.ALL,
                 android.Manifest.permission.READ_PRECISE_PHONE_STATE);
diff --git a/telephony/java/android/telephony/DataFailCause.java b/telephony/java/android/telephony/DataFailCause.java
index c53b37d8ae6a6..26ec6ded82244 100644
--- a/telephony/java/android/telephony/DataFailCause.java
+++ b/telephony/java/android/telephony/DataFailCause.java
@@ -17,6 +17,7 @@ package android.telephony;
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.SystemApi;
 import android.content.Context;
 import android.os.PersistableBundle;
 
@@ -34,6 +35,7 @@ import java.util.Set;
  * Returned as the reason for a data connection failure as defined by modem and some local errors.
  * @hide
  */
+@SystemApi
 public final class DataFailCause {
     /** There is no failure */
     public static final int NONE = 0;
@@ -101,8 +103,8 @@ public final class DataFailCause {
     public static final int PDN_CONN_DOES_NOT_EXIST = 0x36;
     /** Multiple connections to a same PDN is not allowed. */
     public static final int MULTI_CONN_TO_SAME_PDN_NOT_ALLOWED = 0x37;
-    /** Packet Data Protocol (PDP) */
-    public static final int MAX_ACTIVE_PDP_CONTEXT_REACHED = 0x41;
+    /** Max number of Packet Data Protocol (PDP) context reached. */
+    public static final int ACTIVE_PDP_CONTEXT_MAX_NUMBER_REACHED = 0x41;
     /** Unsupported APN in current public land mobile network (PLMN). */
     public static final int UNSUPPORTED_APN_IN_CURRENT_PLMN = 0x42;
     /** Invalid transaction id. */
@@ -165,22 +167,36 @@ public final class DataFailCause {
 
     // Local errors generated by Vendor RIL
     // specified in ril.h
+    /** Data fail due to registration failure. */
     public static final int REGISTRATION_FAIL = -1;
+    /** Data fail due to GPRS registration failure. */
     public static final int GPRS_REGISTRATION_FAIL = -2;
+    /** Data call drop due to network/modem disconnect. */
     public static final int SIGNAL_LOST = -3;                        /* no retry */
+    /**
+     * Preferred technology has changed, must retry with parameters appropriate for new technology.
+     */
     public static final int PREF_RADIO_TECH_CHANGED = -4;
+    /** data call was disconnected because radio was resetting, powered off. */
     public static final int RADIO_POWER_OFF = -5;                    /* no retry */
+    /** Data call was disconnected by modem because tethered. */
     public static final int TETHERED_CALL_ACTIVE = -6;               /* no retry */
+    /** Data call fail due to unspecific errors. */
     public static final int ERROR_UNSPECIFIED = 0xFFFF;
 
     // Errors generated by the Framework
     // specified here
+    /** Unknown data failure cause. */
     public static final int UNKNOWN = 0x10000;
+    /** Data fail due to radio not unavailable. */
     public static final int RADIO_NOT_AVAILABLE = 0x10001;                   /* no retry */
+    /** @hide */
     public static final int UNACCEPTABLE_NETWORK_PARAMETER = 0x10002;        /* no retry */
+    /** @hide */
     public static final int CONNECTION_TO_DATACONNECTIONAC_BROKEN = 0x10003;
+    /** Data connection was lost. */
     public static final int LOST_CONNECTION = 0x10004;
-    /** Data was reset by framework. */
+    /** @hide */
     public static final int RESET_BY_FRAMEWORK = 0x10005;
 
     /** @hide */
@@ -216,7 +232,7 @@ public final class DataFailCause {
             ESM_INFO_NOT_RECEIVED,
             PDN_CONN_DOES_NOT_EXIST,
             MULTI_CONN_TO_SAME_PDN_NOT_ALLOWED,
-            MAX_ACTIVE_PDP_CONTEXT_REACHED,
+            ACTIVE_PDP_CONTEXT_MAX_NUMBER_REACHED,
             UNSUPPORTED_APN_IN_CURRENT_PLMN,
             INVALID_TRANSACTION_ID,
             MESSAGE_INCORRECT_SEMANTIC,
@@ -308,8 +324,8 @@ public final class DataFailCause {
         sFailCauseMap.put(PDN_CONN_DOES_NOT_EXIST, "PDN_CONN_DOES_NOT_EXIST");
         sFailCauseMap.put(MULTI_CONN_TO_SAME_PDN_NOT_ALLOWED,
                 "MULTI_CONN_TO_SAME_PDN_NOT_ALLOWED");
-        sFailCauseMap.put(MAX_ACTIVE_PDP_CONTEXT_REACHED,
-                "MAX_ACTIVE_PDP_CONTEXT_REACHED");
+        sFailCauseMap.put(ACTIVE_PDP_CONTEXT_MAX_NUMBER_REACHED,
+                "ACTIVE_PDP_CONTEXT_MAX_NUMBER_REACHED");
         sFailCauseMap.put(UNSUPPORTED_APN_IN_CURRENT_PLMN,
                 "UNSUPPORTED_APN_IN_CURRENT_PLMN");
         sFailCauseMap.put(INVALID_TRANSACTION_ID, "INVALID_TRANSACTION_ID");
@@ -369,6 +385,9 @@ public final class DataFailCause {
         sFailCauseMap.put(RESET_BY_FRAMEWORK, "RESET_BY_FRAMEWORK");
     }
 
+    private DataFailCause() {
+    }
+
     /**
      * Map of subId -> set of data call setup permanent failure for the carrier.
      */
@@ -382,6 +401,8 @@ public final class DataFailCause {
      * @param cause data disconnect cause
      * @param subId subscription index
      * @return true if the fail cause code needs platform to trigger a modem restart.
+     *
+     * @hide
      */
     public static boolean isRadioRestartFailure(@NonNull Context context, @FailCause int cause,
                                                 int subId) {
@@ -410,6 +431,7 @@ public final class DataFailCause {
         return false;
     }
 
+    /** @hide */
     public static boolean isPermanentFailure(@NonNull Context context, @FailCause int failCause,
                                              int subId) {
         synchronized (sPermanentFailureCache) {
@@ -469,6 +491,7 @@ public final class DataFailCause {
         }
     }
 
+    /** @hide */
     public static boolean isEventLoggable(@FailCause int dataFailCause) {
         return (dataFailCause == OPERATOR_BARRED) || (dataFailCause == INSUFFICIENT_RESOURCES)
                 || (dataFailCause == UNKNOWN_PDP_ADDRESS_TYPE)
@@ -488,11 +511,13 @@ public final class DataFailCause {
                 || (dataFailCause == UNACCEPTABLE_NETWORK_PARAMETER);
     }
 
+    /** @hide */
     public static String toString(@FailCause int dataFailCause) {
         int cause = getFailCause(dataFailCause);
         return (cause == UNKNOWN) ? "UNKNOWN(" + dataFailCause + ")" : sFailCauseMap.get(cause);
     }
 
+    /** @hide */
     public static int getFailCause(@FailCause int failCause) {
         if (sFailCauseMap.containsKey(failCause)) {
             return failCause;
diff --git a/telephony/java/android/telephony/PhoneStateListener.java b/telephony/java/android/telephony/PhoneStateListener.java
index 9317aa73ffc2b..e27b385963246 100644
--- a/telephony/java/android/telephony/PhoneStateListener.java
+++ b/telephony/java/android/telephony/PhoneStateListener.java
@@ -184,14 +184,17 @@ public class PhoneStateListener {
     public static final int LISTEN_PRECISE_CALL_STATE                       = 0x00000800;
 
     /**
-     * Listen for precise changes and fails on the data connection (cellular).
+     * Listen for {@link PreciseDataConnectionState} on the data connection (cellular).
+     *
      * {@more}
      * Requires Permission: {@link android.Manifest.permission#READ_PRECISE_PHONE_STATE
      * READ_PRECISE_PHONE_STATE}
      *
      * @see #onPreciseDataConnectionStateChanged
+     *
      * @hide
      */
+    @SystemApi
     public static final int LISTEN_PRECISE_DATA_CONNECTION_STATE            = 0x00001000;
 
     /**
@@ -564,10 +567,11 @@ public class PhoneStateListener {
 
     /**
      * Callback invoked when data connection state changes with precise information.
+     * @param dataConnectionState {@link PreciseDataConnectionState}
      *
      * @hide
      */
-    @UnsupportedAppUsage
+    @SystemApi
     public void onPreciseDataConnectionStateChanged(
             PreciseDataConnectionState dataConnectionState) {
         // default implementation empty
diff --git a/telephony/java/android/telephony/PreciseDataConnectionState.java b/telephony/java/android/telephony/PreciseDataConnectionState.java
index 83738997a067b..57a18266259a8 100644
--- a/telephony/java/android/telephony/PreciseDataConnectionState.java
+++ b/telephony/java/android/telephony/PreciseDataConnectionState.java
@@ -16,10 +16,12 @@
 
 package android.telephony;
 
+import android.annotation.SystemApi;
 import android.annotation.UnsupportedAppUsage;
 import android.net.LinkProperties;
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.telephony.data.ApnSetting;
 
 import java.util.Objects;
 
@@ -31,7 +33,7 @@ import java.util.Objects;
  * <ul>
  *   <li>Data connection state.
  *   <li>Network type of the connection.
- *   <li>APN type.
+ *   <li>APN types.
  *   <li>APN.
  *   <li>The properties of the network link.
  *   <li>Data connection fail cause.
@@ -39,14 +41,15 @@ import java.util.Objects;
  *
  * @hide
  */
-public class PreciseDataConnectionState implements Parcelable {
+@SystemApi
+public final class PreciseDataConnectionState implements Parcelable {
 
-    private int mState = TelephonyManager.DATA_UNKNOWN;
-    private int mNetworkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
-    private String mAPNType = "";
+    private @TelephonyManager.DataState int mState = TelephonyManager.DATA_UNKNOWN;
+    private @TelephonyManager.NetworkType int mNetworkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
+    private @DataFailCause.FailCause int mFailCause = DataFailCause.NONE;
+    private @ApnSetting.ApnType int mAPNTypes = ApnSetting.TYPE_NONE;
     private String mAPN = "";
     private LinkProperties mLinkProperties = null;
-    private String mFailCause = "";
 
     /**
      * Constructor
@@ -54,11 +57,14 @@ public class PreciseDataConnectionState implements Parcelable {
      * @hide
      */
     @UnsupportedAppUsage
-    public PreciseDataConnectionState(int state, int networkType, String apnType, String apn,
-                                      LinkProperties linkProperties, String failCause) {
+    public PreciseDataConnectionState(@TelephonyManager.DataState int state,
+                                      @TelephonyManager.NetworkType int networkType,
+                                      @ApnSetting.ApnType int apnTypes, String apn,
+                                      LinkProperties linkProperties,
+                                      @DataFailCause.FailCause int failCause) {
         mState = state;
         mNetworkType = networkType;
-        mAPNType = apnType;
+        mAPNTypes = apnTypes;
         mAPN = apn;
         mLinkProperties = linkProperties;
         mFailCause = failCause;
@@ -74,73 +80,52 @@ public class PreciseDataConnectionState implements Parcelable {
 
     /**
      * Construct a PreciseDataConnectionState object from the given parcel.
+     *
+     * @hide
      */
     private PreciseDataConnectionState(Parcel in) {
         mState = in.readInt();
         mNetworkType = in.readInt();
-        mAPNType = in.readString();
+        mAPNTypes = in.readInt();
         mAPN = in.readString();
         mLinkProperties = (LinkProperties)in.readParcelable(null);
-        mFailCause = in.readString();
+        mFailCause = in.readInt();
     }
 
     /**
-     * Get data connection state
-     *
-     * @see TelephonyManager#DATA_UNKNOWN
-     * @see TelephonyManager#DATA_DISCONNECTED
-     * @see TelephonyManager#DATA_CONNECTING
-     * @see TelephonyManager#DATA_CONNECTED
-     * @see TelephonyManager#DATA_SUSPENDED
+     * Returns the state of data connection that supported the apn types returned by
+     * {@link #getDataConnectionApnTypeBitMask()}
      */
-    @UnsupportedAppUsage
-    public int getDataConnectionState() {
+    public @TelephonyManager.DataState int getDataConnectionState() {
         return mState;
     }
 
     /**
-     * Get data connection network type
-     *
-     * @see TelephonyManager#NETWORK_TYPE_UNKNOWN
-     * @see TelephonyManager#NETWORK_TYPE_GPRS
-     * @see TelephonyManager#NETWORK_TYPE_EDGE
-     * @see TelephonyManager#NETWORK_TYPE_UMTS
-     * @see TelephonyManager#NETWORK_TYPE_CDMA
-     * @see TelephonyManager#NETWORK_TYPE_EVDO_0
-     * @see TelephonyManager#NETWORK_TYPE_EVDO_A
-     * @see TelephonyManager#NETWORK_TYPE_1xRTT
-     * @see TelephonyManager#NETWORK_TYPE_HSDPA
-     * @see TelephonyManager#NETWORK_TYPE_HSUPA
-     * @see TelephonyManager#NETWORK_TYPE_HSPA
-     * @see TelephonyManager#NETWORK_TYPE_IDEN
-     * @see TelephonyManager#NETWORK_TYPE_EVDO_B
-     * @see TelephonyManager#NETWORK_TYPE_LTE
-     * @see TelephonyManager#NETWORK_TYPE_EHRPD
-     * @see TelephonyManager#NETWORK_TYPE_HSPAP
+     * Returns the network type associated with this data connection.
+     * @hide
      */
-    @UnsupportedAppUsage
-    public int getDataConnectionNetworkType() {
+    public @TelephonyManager.NetworkType int getDataConnectionNetworkType() {
         return mNetworkType;
     }
 
     /**
-     * Get data connection APN type
+     * Returns the data connection APN types supported by this connection and triggers
+     * {@link PreciseDataConnectionState} change.
      */
-    @UnsupportedAppUsage
-    public String getDataConnectionAPNType() {
-        return mAPNType;
+    public @ApnSetting.ApnType int getDataConnectionApnTypeBitMask() {
+        return mAPNTypes;
     }
 
     /**
-     * Get data connection APN.
+     * Returns APN {@link ApnSetting} of this data connection.
      */
-    @UnsupportedAppUsage
-    public String getDataConnectionAPN() {
+    public String getDataConnectionApn() {
         return mAPN;
     }
 
     /**
-     * Get the properties of the network link.
+     * Get the properties of the network link {@link LinkProperties}.
+     * @hide
      */
     @UnsupportedAppUsage
     public LinkProperties getDataConnectionLinkProperties() {
@@ -148,10 +133,9 @@ public class PreciseDataConnectionState implements Parcelable {
     }
 
     /**
-     * Get data connection fail cause, in case there was a failure.
+     * Returns data connection fail cause, in case there was a failure.
      */
-    @UnsupportedAppUsage
-    public String getDataConnectionFailCause() {
+    public @DataFailCause.FailCause int getDataConnectionFailCause() {
         return mFailCause;
     }
 
@@ -164,10 +148,10 @@ public class PreciseDataConnectionState implements Parcelable {
     public void writeToParcel(Parcel out, int flags) {
         out.writeInt(mState);
         out.writeInt(mNetworkType);
-        out.writeString(mAPNType);
+        out.writeInt(mAPNTypes);
         out.writeString(mAPN);
         out.writeParcelable(mLinkProperties, flags);
-        out.writeString(mFailCause);
+        out.writeInt(mFailCause);
     }
 
     public static final Parcelable.Creator<PreciseDataConnectionState> CREATOR
@@ -184,56 +168,23 @@ public class PreciseDataConnectionState implements Parcelable {
 
     @Override
     public int hashCode() {
-        return Objects.hash(mState, mNetworkType, mAPNType, mAPN, mLinkProperties, mFailCause);
+        return Objects.hash(mState, mNetworkType, mAPNTypes, mAPN, mLinkProperties,
+                mFailCause);
     }
 
     @Override
     public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null) {
-            return false;
-        }
-        if (getClass() != obj.getClass()) {
+
+        if (!(obj instanceof PreciseDataConnectionState)) {
             return false;
         }
+
         PreciseDataConnectionState other = (PreciseDataConnectionState) obj;
-        if (mAPN == null) {
-            if (other.mAPN != null) {
-                return false;
-            }
-        } else if (!mAPN.equals(other.mAPN)) {
-            return false;
-        }
-        if (mAPNType == null) {
-            if (other.mAPNType != null) {
-                return false;
-            }
-        } else if (!mAPNType.equals(other.mAPNType)) {
-            return false;
-        }
-        if (mFailCause == null) {
-            if (other.mFailCause != null) {
-                return false;
-            }
-        } else if (!mFailCause.equals(other.mFailCause)) {
-            return false;
-        }
-        if (mLinkProperties == null) {
-            if (other.mLinkProperties != null) {
-                return false;
-            }
-        } else if (!mLinkProperties.equals(other.mLinkProperties)) {
-            return false;
-        }
-        if (mNetworkType != other.mNetworkType) {
-            return false;
-        }
-        if (mState != other.mState) {
-            return false;
-        }
-        return true;
+        return Objects.equals(mAPN, other.mAPN) && mAPNTypes == other.mAPNTypes
+                && mFailCause == other.mFailCause
+                && Objects.equals(mLinkProperties, other.mLinkProperties)
+                && mNetworkType == other.mNetworkType
+                && mState == other.mState;
     }
 
     @Override
@@ -242,10 +193,10 @@ public class PreciseDataConnectionState implements Parcelable {
 
         sb.append("Data Connection state: " + mState);
         sb.append(", Network type: " + mNetworkType);
-        sb.append(", APN type: " + mAPNType);
+        sb.append(", APN types: " + ApnSetting.getApnTypesStringFromBitmask(mAPNTypes));
         sb.append(", APN: " + mAPN);
         sb.append(", Link properties: " + mLinkProperties);
-        sb.append(", Fail cause: " + mFailCause);
+        sb.append(", Fail cause: " + DataFailCause.toString(mFailCause));
 
         return sb.toString();
     }
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 739c80fd9d976..1d8ee791c551f 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -4558,9 +4558,18 @@ public class TelephonyManager {
       }
     }
 
-    /** Data connection state: Unknown.  Used before we know the state.
-     * @hide
-     */
+    /** @hide */
+    @IntDef(prefix = {"DATA_"}, value = {
+            DATA_UNKNOWN,
+            DATA_DISCONNECTED,
+            DATA_CONNECTING,
+            DATA_CONNECTED,
+            DATA_SUSPENDED,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface DataState{}
+
+    /** Data connection state: Unknown.  Used before we know the state. */
     public static final int DATA_UNKNOWN        = -1;
     /** Data connection state: Disconnected. IP traffic not available. */
     public static final int DATA_DISCONNECTED   = 0;
diff --git a/telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl b/telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl
index 02a6f311c1da7..5632c630999bf 100644
--- a/telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephonyRegistry.aidl
@@ -68,7 +68,7 @@ interface ITelephonyRegistry {
             int backgroundCallState);
     void notifyDisconnectCause(int disconnectCause, int preciseDisconnectCause);
     void notifyPreciseDataConnectionFailed(String apnType, String apn,
-            String failCause);
+            int failCause);
     void notifyCellInfoForSubscriber(in int subId, in List<CellInfo> cellInfo);
     void notifySrvccStateChanged(in int subId, in int lteState);
     void notifySimActivationStateChangedForPhoneId(in int phoneId, in int subId,