diff --git a/current.txt b/current.txt
index b0b9529..665977d 100644
--- a/current.txt
+++ b/current.txt
@@ -648,11 +648,13 @@
 881aa8720fb1d69aa9843bfab69d810ab7654a61d2f5ab5e2626cbf240f24eaf android.hardware.dumpstate@1.1::types
 13b33f623521ded51a6c0f7ea5b77e97066d0aa1e38a83c2873f08ad67294f89 android.hardware.dumpstate@1.1::IDumpstateDevice
 769d346927a94fd40ee80a5a976d8d15cf022ef99c5900738f4a82f26c0ed229 android.hardware.gnss@2.1::types
-88371e0edf69a1f72bfc45ecb2335e9b145e87339d3eecc92664a1fb200213ba android.hardware.gnss@2.1::IGnss
-ba62e1e8993bfb9f27fa04816fa0f2241ae2d01edfa3d0c04182e2e5de80045c android.hardware.gnss@2.1::IGnssCallback
-ccdf3c0fb2c02a6d4dc57afb276c3497ae8172b80b00ebc0bf8a0238dd38b01d android.hardware.gnss@2.1::IGnssConfiguration
-5a125c49ca83629e22afc8c39e865509343bfa2c38f0baea9a186bbac103492d android.hardware.gnss@2.1::IGnssMeasurement
-d7bf37660a0946de9599dcbae997b077ee3e604fc2044534d40d3da04297a5d3 android.hardware.gnss@2.1::IGnssMeasurementCallback
+626db710bf917ecf551a0b0b1f25be10bf52758f43e0fc808b148b6aae2ef73e android.hardware.gnss@2.1::IGnss
+ba5ac712b2a656dc07c83ab4a7a2c2f3bee1bbcb752e8b8ffa9b672f3b5b0728 android.hardware.gnss@2.1::IGnssAntennaInfo
+0bc3ed97cbc3f6abc89c68f4e9f4d124f9f723431997dc88c2186cf4d2ad47ee android.hardware.gnss@2.1::IGnssAntennaInfoCallback
+50c5d009af76d65b3023a9d94ee519545e72cb7c59bc7166d768d6f00923774d android.hardware.gnss@2.1::IGnssCallback
+737d750017738f0753d13ba01a3310e0161f294b8ae80b3fd63eaa227e9d9c66 android.hardware.gnss@2.1::IGnssConfiguration
+7913a11206a577b12ade86a7cf3f95c2639cb514d086673f279bf99238c9917e android.hardware.gnss@2.1::IGnssMeasurement
+9999f2484f35ebfacdd433dfeae459f2a582334315959653ec8efde7699ec556 android.hardware.gnss@2.1::IGnssMeasurementCallback
 6670e7780803a8c696c6391fda5589a334b1b37dc7be9393792ed35035413633 android.hardware.gnss.measurement_corrections@1.1::IMeasurementCorrections
 a3f439b782a6a92aaf3c0250f3526e94e8bf8844c3d578f0815e21b12c431346 android.hardware.gnss.measurement_corrections@1.1::types
 ce8dbe76eb9ee94b46ef98f725be992e760a5751073d4f4912484026541371f3 android.hardware.health@2.1::IHealth
diff --git a/gnss/2.1/Android.bp b/gnss/2.1/Android.bp
index 7efc4a6..2122399 100644
--- a/gnss/2.1/Android.bp
+++ b/gnss/2.1/Android.bp
@@ -9,6 +9,8 @@
     srcs: [
         "types.hal",
         "IGnss.hal",
+        "IGnssAntennaInfo.hal",
+        "IGnssAntennaInfoCallback.hal",
         "IGnssCallback.hal",
         "IGnssMeasurement.hal",
         "IGnssMeasurementCallback.hal",
diff --git a/gnss/2.1/IGnss.hal b/gnss/2.1/IGnss.hal
index ce37647..e4da507 100644
--- a/gnss/2.1/IGnss.hal
+++ b/gnss/2.1/IGnss.hal
@@ -18,10 +18,10 @@
 
 import android.hardware.gnss.measurement_corrections@1.1::IMeasurementCorrections;
 import @2.0::IGnss;
-
 import IGnssCallback;
 import IGnssMeasurement;
 import IGnssConfiguration;
+import IGnssAntennaInfo;
 
 /**
  * Represents the standard GNSS (Global Navigation Satellite System) interface.
@@ -72,5 +72,15 @@
      *
      * @return measurementCorrectionsIface Handle to the IMeasurementCorrections interface.
      */
-     getExtensionMeasurementCorrections_1_1() generates (IMeasurementCorrections measurementCorrectionsIface);
-};
\ No newline at end of file
+    getExtensionMeasurementCorrections_1_1()
+        generates (IMeasurementCorrections measurementCorrectionsIface);
+
+    /**
+     * This method returns the IGnssAntennaInfo interface.
+     *
+     * This method must return non-null.
+     *
+     * @return gnssAntennaInfoIface Handle to the IGnssAntennaInfo interface.
+     */
+    getExtensionGnssAntennaInfo() generates (IGnssAntennaInfo gnssAntennaInfoIface);
+};
diff --git a/gnss/2.1/IGnssAntennaInfo.hal b/gnss/2.1/IGnssAntennaInfo.hal
new file mode 100644
index 0000000..f77d874
--- /dev/null
+++ b/gnss/2.1/IGnssAntennaInfo.hal
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2020 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.hardware.gnss@2.1;
+
+import IGnssAntennaInfoCallback;
+
+/**
+ * Extended interface for GNSS antenna information support.
+ */
+interface IGnssAntennaInfo {
+    enum GnssAntennaInfoStatus : int32_t {
+        SUCCESS = 0,
+        ERROR_ALREADY_INIT = -100,
+        ERROR_GENERIC = -101,
+    };
+
+    /**
+     * Registers the callback routines with the HAL.
+     *
+     * @param callback Handle to the GnssAntennaInfo callback interface.
+     */
+    setCallback(IGnssAntennaInfoCallback callback) generates (GnssAntennaInfoStatus initRet);
+
+    /**
+     * Stops updates from the HAL, and unregisters the callback routines.
+     * After a call to close(), the previously registered callbacks must be
+     * considered invalid by the HAL.
+     * If close() is invoked without a previous setCallback, this function must perform
+     * no work.
+     */
+    close();
+};
diff --git a/gnss/2.1/IGnssAntennaInfoCallback.hal b/gnss/2.1/IGnssAntennaInfoCallback.hal
new file mode 100644
index 0000000..883111e
--- /dev/null
+++ b/gnss/2.1/IGnssAntennaInfoCallback.hal
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2020 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.hardware.gnss@2.1;
+
+/**
+ * The callback interface to report GNSS antenna information from the HAL.
+ */
+interface IGnssAntennaInfoCallback {
+    /**
+     * A row of doubles. This is used to represent a row in a 2D array, which are used to
+     * characterize the phase center variation corrections and signal gain corrections.
+     */
+    struct Row {
+        vec<double> row;
+    };
+
+    /**
+     * A point in 3D space, with associated uncertainty.
+     */
+    struct Coord {
+        double x;
+
+        double xUncertainty;
+
+        double y;
+
+        double yUncertainty;
+
+        double z;
+
+        double zUncertainty;
+    };
+
+    struct GnssAntennaInfo {
+        /**
+         * The carrier frequency in MHz.
+         */
+        double carrierFrequencyMHz;
+
+        /**
+         * Phase center offset (PCO) with associated 1-sigma uncertainty. PCO is defined with
+         * respect to the origin of the Android sensor coordinate system, e.g., center of primary
+         * screen for mobiles - see sensor or form factor documents for details.
+         */
+        Coord phaseCenterOffsetCoordinateMillimeters;
+
+        /**
+         * 2D vectors representing the phase center variation (PCV) corrections, in
+         * millimeters, at regularly spaced azimuthal angle (theta) and zenith angle
+         * (phi). The PCV correction is added to the phase measurement to obtain the
+         * corrected value.
+         *
+         * The azimuthal angle, theta, is defined with respect to the X axis of the
+         * Android sensor coordinate system, increasing toward the Y axis. The zenith
+         * angle, phi, is defined with respect to the Z axis of the Android Sensor
+         * coordinate system, increasing toward the X-Y plane.
+         *
+         * Each row vector (outer vectors) represents a fixed theta. The first row
+         * corresponds to a theta angle of 0 degrees. The last row corresponds to a
+         * theta angle of (360 - deltaTheta) degrees, where deltaTheta is the regular
+         * spacing between azimuthal angles, i.e., deltaTheta = 360 / (number of rows).
+         *
+         * The columns (inner vectors) represent fixed zenith angles, beginning at 0
+         * degrees and ending at 180 degrees. They are separated by deltaPhi, the regular
+         * spacing between zenith angles, i.e., deltaPhi = 180 / (number of columns - 1).
+         *
+         * This field is optional, i.e., an empty vector.
+         */
+        vec<Row> phaseCenterVariationCorrectionMillimeters;
+
+        /**
+         * 2D vectors of 1-sigma uncertainty in millimeters associated with the PCV
+         * correction values.
+         *
+         * This field is optional, i.e., an empty vector.
+         */
+        vec<Row> phaseCenterVariationCorrectionUncertaintyMillimeters;
+
+        /**
+         * 2D vectors representing the signal gain corrections at regularly spaced
+         * azimuthal angle (theta) and zenith angle (phi). The values are calculated or
+         * measured at the antenna feed point without considering the radio and receiver
+         * noise figure and path loss contribution, in dBi, i.e., decibel over isotropic
+         * antenna with the same total power. The signal gain correction is added the
+         * signal gain measurement to obtain the corrected value.
+         *
+         * The azimuthal angle, theta, is defined with respect to the X axis of the
+         * Android sensor coordinate system, increasing toward the Y axis. The zenith
+         * angle, phi, is defined with respect to the Z axis of the Android Sensor
+         * coordinate system, increasing toward the X-Y plane.
+         *
+         * Each row vector (outer vectors) represents a fixed theta. The first row
+         * corresponds to a theta angle of 0 degrees. The last row corresponds to a
+         * theta angle of (360 - deltaTheta) degrees, where deltaTheta is the regular
+         * spacing between azimuthal angles, i.e., deltaTheta = 360 / (number of rows).
+         *
+         * The columns (inner vectors) represent fixed zenith angles, beginning at 0
+         * degrees and ending at 180 degrees. They are separated by deltaPhi, the regular
+         * spacing between zenith angles, i.e., deltaPhi = 180 / (number of columns - 1).
+         *
+         * This field is optional, i.e., an empty vector.
+         */
+        vec<Row> signalGainCorrectionDbi;
+
+        /**
+         * 2D vectors of 1-sigma uncertainty in dBi associated with the signal
+         * gain correction values.
+         *
+         * This field is optional, i.e., an empty vector.
+         */
+        vec<Row> signalGainCorrectionUncertaintyDbi;
+    };
+
+    /**
+     * Called when on connection, and on known-change to these values, such as upon a known
+     * GNSS RF antenna tuning change, or a foldable device state change.
+     *
+     * This is optional. It can never be called if the GNSS antenna information is not
+     * available.
+     */
+    gnssAntennaInfoCb(vec<GnssAntennaInfo> gnssAntennaInfos);
+};
diff --git a/gnss/2.1/IGnssCallback.hal b/gnss/2.1/IGnssCallback.hal
index da70742..f7b7477 100644
--- a/gnss/2.1/IGnssCallback.hal
+++ b/gnss/2.1/IGnssCallback.hal
@@ -24,8 +24,20 @@
  * the interfaces and passes a handle to the HAL.
  */
 interface IGnssCallback extends @2.0::IGnssCallback {
+    /**
+     * Flags for the gnssSetCapabilities callback.
+     */
+    @export(name = "", value_prefix = "GPS_CAPABILITY_")
+    enum Capabilities : @2.0::IGnssCallback.Capabilities {
+        /**
+         * GNSS supports measurement corrections
+         */
+        ANTENNA_INFO = 1 << 11,
+    };
 
-    /** Extends a GnssSvInfo, adding a basebandCN0DbHz. */
+    /**
+     * Extends a GnssSvInfo, adding a basebandCN0DbHz.
+     */
     struct GnssSvInfo {
         /**
          * GNSS satellite information for a single satellite and frequency.
diff --git a/gnss/2.1/IGnssConfiguration.hal b/gnss/2.1/IGnssConfiguration.hal
index 8360ba9..550f325 100644
--- a/gnss/2.1/IGnssConfiguration.hal
+++ b/gnss/2.1/IGnssConfiguration.hal
@@ -65,4 +65,4 @@
      * @return success Whether the HAL accepts and abides by the provided blacklist.
      */
     setBlacklist_2_1(vec<BlacklistedSource> blacklist) generates (bool success);
-};
\ No newline at end of file
+};
diff --git a/gnss/2.1/IGnssMeasurement.hal b/gnss/2.1/IGnssMeasurement.hal
index d2c76e6..49ba7eb 100644
--- a/gnss/2.1/IGnssMeasurement.hal
+++ b/gnss/2.1/IGnssMeasurement.hal
@@ -25,7 +25,6 @@
  * Extended interface for GNSS Measurements support.
  */
 interface IGnssMeasurement extends @2.0::IGnssMeasurement {
-
     /**
      * Initializes the interface and registers the callback routines with the HAL. After a
      * successful call to 'setCallback_2_1' the HAL must begin to provide updates at an average
@@ -47,5 +46,5 @@
      *     error code.
      */
     setCallback_2_1(IGnssMeasurementCallback callback, bool enableFullTracking)
-         generates (GnssMeasurementStatus initRet);
+        generates (GnssMeasurementStatus initRet);
 };
diff --git a/gnss/2.1/IGnssMeasurementCallback.hal b/gnss/2.1/IGnssMeasurementCallback.hal
index 0385abd..1aee272 100644
--- a/gnss/2.1/IGnssMeasurementCallback.hal
+++ b/gnss/2.1/IGnssMeasurementCallback.hal
@@ -21,36 +21,56 @@
 import @2.0::ElapsedRealtime;
 import GnssSignalType;
 
-/** The callback interface to report measurements from the HAL. */
+/**
+ * The callback interface to report measurements from the HAL.
+ */
 interface IGnssMeasurementCallback extends @2.0::IGnssMeasurementCallback {
-
     /**
      * Flags to indicate what fields in GnssMeasurement are valid.
      */
     enum GnssMeasurementFlags : uint32_t {
-        /** A valid 'snr' is stored in the data structure. */
-        HAS_SNR                           = 1 << 0,
-        /** A valid 'carrier frequency' is stored in the data structure. */
-        HAS_CARRIER_FREQUENCY             = 1 << 9,
-        /** A valid 'carrier cycles' is stored in the data structure. */
-        HAS_CARRIER_CYCLES                = 1 << 10,
-        /** A valid 'carrier phase' is stored in the data structure. */
-        HAS_CARRIER_PHASE                 = 1 << 11,
-        /** A valid 'carrier phase uncertainty' is stored in the data structure. */
-        HAS_CARRIER_PHASE_UNCERTAINTY     = 1 << 12,
-        /** A valid automatic gain control is stored in the data structure. */
-        HAS_AUTOMATIC_GAIN_CONTROL        = 1 << 13,
-        /** A valid receiver inter-signal bias is stored in the data structure. */
-        HAS_RECEIVER_ISB                  = 1 << 16,
-        /** A valid receiver inter-signal bias uncertainty is stored in the data structure. */
-        HAS_RECEIVER_ISB_UNCERTAINTY      = 1 << 17,
-        /** A valid satellite inter-signal bias is stored in the data structure. */
-        HAS_SATELLITE_ISB                 = 1 << 18,
-        /** A valid satellite inter-signal bias uncertainty is stored in the data structure. */
-        HAS_SATELLITE_ISB_UNCERTAINTY     = 1 << 19
+        /**
+         * A valid 'snr' is stored in the data structure.
+         */
+        HAS_SNR = 1 << 0,
+        /**
+         * A valid 'carrier frequency' is stored in the data structure.
+         */
+        HAS_CARRIER_FREQUENCY = 1 << 9,
+        /**
+         * A valid 'carrier cycles' is stored in the data structure.
+         */
+        HAS_CARRIER_CYCLES = 1 << 10,
+        /**
+         * A valid 'carrier phase' is stored in the data structure.
+         */
+        HAS_CARRIER_PHASE = 1 << 11,
+        /**
+         * A valid 'carrier phase uncertainty' is stored in the data structure.
+         */
+        HAS_CARRIER_PHASE_UNCERTAINTY = 1 << 12,
+        /**
+         * A valid automatic gain control is stored in the data structure.
+         */
+        HAS_AUTOMATIC_GAIN_CONTROL = 1 << 13,
+        /**
+         * A valid receiver inter-signal bias is stored in the data structure.
+         */
+        HAS_RECEIVER_ISB = 1 << 16,
+        /**
+         * A valid receiver inter-signal bias uncertainty is stored in the data structure.
+         */
+        HAS_RECEIVER_ISB_UNCERTAINTY = 1 << 17,
+        /**
+         * A valid satellite inter-signal bias is stored in the data structure.
+         */
+        HAS_SATELLITE_ISB = 1 << 18,
+        /**
+         * A valid satellite inter-signal bias uncertainty is stored in the data structure.
+         */
+        HAS_SATELLITE_ISB_UNCERTAINTY = 1 << 19,
     };
 
-
     /**
      * Extends a GNSS Measurement, adding basebandCN0DbHz, GnssMeasurementFlags,
      * receiverInterSignalBiasNs, receiverInterSignalBiasUncertaintyNs, satelliteInterSignalBiasNs
@@ -160,10 +180,14 @@
      * Complete set of GNSS Measurement data, same as 2.0 with additional fields in measurements.
      */
     struct GnssData {
-        /** The full set of satellite measurement observations. */
+        /**
+         * The full set of satellite measurement observations.
+         */
         vec<GnssMeasurement> measurements;
 
-        /** The GNSS clock time reading. */
+        /**
+         * The GNSS clock time reading.
+         */
         GnssClock clock;
 
         /**
diff --git a/gnss/2.1/default/Android.bp b/gnss/2.1/default/Android.bp
index 1f1078e..c4dc8fd 100644
--- a/gnss/2.1/default/Android.bp
+++ b/gnss/2.1/default/Android.bp
@@ -22,6 +22,7 @@
     vintf_fragments: ["android.hardware.gnss@2.1-service.xml"],
     srcs: [
         "Gnss.cpp",
+        "GnssAntennaInfo.cpp",
         "GnssDebug.cpp",
         "GnssMeasurement.cpp",
         "GnssMeasurementCorrections.cpp",
diff --git a/gnss/2.1/default/Gnss.cpp b/gnss/2.1/default/Gnss.cpp
index 679eb35..c1af103 100644
--- a/gnss/2.1/default/Gnss.cpp
+++ b/gnss/2.1/default/Gnss.cpp
@@ -17,6 +17,7 @@
 #define LOG_TAG "Gnss"
 
 #include "Gnss.h"
+#include "GnssAntennaInfo.h"
 #include "GnssDebug.h"
 #include "GnssMeasurement.h"
 #include "GnssMeasurementCorrections.h"
@@ -334,9 +335,10 @@
 
     sGnssCallback_2_1 = callback;
 
-    using Capabilities = V2_0::IGnssCallback::Capabilities;
+    using Capabilities = V2_1::IGnssCallback::Capabilities;
     const auto capabilities = Capabilities::MEASUREMENTS | Capabilities::MEASUREMENT_CORRECTIONS |
-                              Capabilities::LOW_POWER_MODE | Capabilities::SATELLITE_BLACKLIST;
+                              Capabilities::LOW_POWER_MODE | Capabilities::SATELLITE_BLACKLIST |
+                              Capabilities::ANTENNA_INFO;
     auto ret = sGnssCallback_2_1->gnssSetCapabilitiesCb_2_0(capabilities);
     if (!ret.isOk()) {
         ALOGE("%s: Unable to invoke callback", __func__);
@@ -374,6 +376,11 @@
     return new GnssMeasurementCorrections();
 }
 
+Return<sp<V2_1::IGnssAntennaInfo>> Gnss::getExtensionGnssAntennaInfo() {
+    ALOGD("Gnss::getExtensionGnssAntennaInfo");
+    return new GnssAntennaInfo();
+}
+
 void Gnss::reportSvStatus(const hidl_vec<GnssSvInfo>& svInfoList) const {
     std::unique_lock<std::mutex> lock(mMutex);
     // TODO(skz): update this to call 2_0 callback if non-null
diff --git a/gnss/2.1/default/Gnss.h b/gnss/2.1/default/Gnss.h
index c47206a..bd5e6e8 100644
--- a/gnss/2.1/default/Gnss.h
+++ b/gnss/2.1/default/Gnss.h
@@ -22,6 +22,7 @@
 #include <atomic>
 #include <mutex>
 #include <thread>
+#include "GnssAntennaInfo.h"
 #include "GnssConfiguration.h"
 
 namespace android {
@@ -91,6 +92,7 @@
     Return<sp<V2_1::IGnssConfiguration>> getExtensionGnssConfiguration_2_1() override;
     Return<sp<measurement_corrections::V1_1::IMeasurementCorrections>>
     getExtensionMeasurementCorrections_1_1() override;
+    Return<sp<V2_1::IGnssAntennaInfo>> getExtensionGnssAntennaInfo() override;
 
   private:
     void reportLocation(const V2_0::GnssLocation&) const;
diff --git a/gnss/2.1/default/GnssAntennaInfo.cpp b/gnss/2.1/default/GnssAntennaInfo.cpp
new file mode 100644
index 0000000..d32a0af
--- /dev/null
+++ b/gnss/2.1/default/GnssAntennaInfo.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "GnssAntennaInfo"
+
+#include "GnssAntennaInfo.h"
+#include "Utils.h"
+
+#include <log/log.h>
+
+using ::android::hardware::gnss::common::Utils;
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+sp<IGnssAntennaInfoCallback> GnssAntennaInfo::sCallback = nullptr;
+
+GnssAntennaInfo::GnssAntennaInfo() : mMinIntervalMillis(1000) {}
+
+GnssAntennaInfo::~GnssAntennaInfo() {
+    stop();
+}
+
+// Methods from ::android::hardware::gnss::V2_1::IGnssAntennaInfo follow.
+Return<GnssAntennaInfo::GnssAntennaInfoStatus> GnssAntennaInfo::setCallback(
+        const sp<IGnssAntennaInfoCallback>& callback) {
+    ALOGD("setCallback");
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback = callback;
+
+    if (mIsActive) {
+        ALOGW("GnssAntennaInfo callback already set. Resetting the callback...");
+        stop();
+    }
+    start();
+
+    return GnssAntennaInfoStatus::SUCCESS;
+}
+
+Return<void> GnssAntennaInfo::close() {
+    ALOGD("close");
+    std::unique_lock<std::mutex> lock(mMutex);
+    stop();
+    sCallback = nullptr;
+    return Void();
+}
+
+// Private methods
+void GnssAntennaInfo::start() {
+    ALOGD("start");
+    mIsActive = true;
+    mThread = std::thread([this]() {
+        while (mIsActive == true) {
+            if (sCallback != nullptr) {
+                auto antennaInfos = Utils::getMockAntennaInfos();
+                this->reportAntennaInfo(antennaInfos);
+            }
+
+            /** For mock implementation this is good. On real device, we should only report
+                antennaInfo at start and when there is a configuration change. **/
+            std::this_thread::sleep_for(std::chrono::milliseconds(mMinIntervalMillis));
+        }
+    });
+}
+
+void GnssAntennaInfo::stop() {
+    ALOGD("stop");
+    mIsActive = false;
+    if (mThread.joinable()) {
+        mThread.join();
+    }
+}
+
+void GnssAntennaInfo::reportAntennaInfo(
+        const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& antennaInfo) const {
+    std::unique_lock<std::mutex> lock(mMutex);
+
+    if (sCallback == nullptr) {
+        ALOGE("%s: No non-null callback", __func__);
+        return;
+    }
+
+    auto ret = sCallback->gnssAntennaInfoCb(antennaInfo);
+    if (!ret.isOk()) {
+        ALOGE("%s: Unable to invoke callback", __func__);
+    }
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
\ No newline at end of file
diff --git a/gnss/2.1/default/GnssAntennaInfo.h b/gnss/2.1/default/GnssAntennaInfo.h
new file mode 100644
index 0000000..f4bfd24
--- /dev/null
+++ b/gnss/2.1/default/GnssAntennaInfo.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#ifndef ANDROID_HARDWARE_GNSS_V2_1_GNSSANTENNAINFO_H
+#define ANDROID_HARDWARE_GNSS_V2_1_GNSSANTENNAINFO_H
+
+#include <android/hardware/gnss/2.1/IGnssAntennaInfo.h>
+
+#include <mutex>
+#include <thread>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+struct GnssAntennaInfo : public IGnssAntennaInfo {
+    GnssAntennaInfo();
+    ~GnssAntennaInfo();
+
+    // Methods from ::android::hardware::gnss::V2_1::IGnssAntennaInfo follow.
+    Return<GnssAntennaInfoStatus> setCallback(
+            const sp<IGnssAntennaInfoCallback>& callback) override;
+    Return<void> close() override;
+
+  private:
+    void start();
+    void stop();
+    void reportAntennaInfo(
+            const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& antennaInfo) const;
+
+    static sp<IGnssAntennaInfoCallback> sCallback;
+    std::atomic<long> mMinIntervalMillis;
+    std::atomic<bool> mIsActive;
+    std::thread mThread;
+    mutable std::mutex mMutex;
+};
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GNSS_V2_1_GNSSCONFIGURATION_H
\ No newline at end of file
diff --git a/gnss/2.1/vts/functional/gnss_hal_test.cpp b/gnss/2.1/vts/functional/gnss_hal_test.cpp
index 93f89f5..83c4c3c 100644
--- a/gnss/2.1/vts/functional/gnss_hal_test.cpp
+++ b/gnss/2.1/vts/functional/gnss_hal_test.cpp
@@ -262,4 +262,11 @@
     ALOGI("GnssMeasurementCorrectionsCallback capabilities received %d", capabilities);
     capabilities_cbq_.store(capabilities);
     return Void();
+}
+
+Return<void> GnssHalTest::GnssAntennaInfoCallback::gnssAntennaInfoCb(
+        const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& gnssAntennaInfos) {
+    ALOGD("GnssAntennaInfo v2.1 received. Size = %d", (int)gnssAntennaInfos.size());
+    antenna_info_cbq_.store(gnssAntennaInfos);
+    return Void();
 }
\ No newline at end of file
diff --git a/gnss/2.1/vts/functional/gnss_hal_test.h b/gnss/2.1/vts/functional/gnss_hal_test.h
index b99cf23..3472edb 100644
--- a/gnss/2.1/vts/functional/gnss_hal_test.h
+++ b/gnss/2.1/vts/functional/gnss_hal_test.h
@@ -31,6 +31,8 @@
 using android::hardware::gnss::V1_0::GnssLocationFlags;
 using android::hardware::gnss::V2_0::GnssConstellationType;
 using android::hardware::gnss::V2_1::IGnss;
+using android::hardware::gnss::V2_1::IGnssAntennaInfo;
+using android::hardware::gnss::V2_1::IGnssAntennaInfoCallback;
 
 using GnssLocation_1_0 = android::hardware::gnss::V1_0::GnssLocation;
 using GnssLocation_2_0 = android::hardware::gnss::V2_0::GnssLocation;
@@ -152,6 +154,20 @@
         Return<void> setCapabilitiesCb(uint32_t capabilities) override;
     };
 
+    /* Callback class for GnssAntennaInfo. */
+    class GnssAntennaInfoCallback : public IGnssAntennaInfoCallback {
+      public:
+        GnssCallbackEventQueue<hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>>
+                antenna_info_cbq_;
+
+        GnssAntennaInfoCallback() : antenna_info_cbq_("info"){};
+        virtual ~GnssAntennaInfoCallback() = default;
+
+        // Methods from V2_1::GnssAntennaInfoCallback follow.
+        Return<void> gnssAntennaInfoCb(
+                const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& gnssAntennaInfos);
+    };
+
     /*
      * SetUpGnssCallback:
      *   Set GnssCallback and verify the result.
diff --git a/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp b/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
index 9ac9436..7b054c0 100644
--- a/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
+++ b/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
@@ -139,7 +139,7 @@
             std::string codeType = lastMeasurement.clock.referenceSignalTypeForIsb.codeType;
 
             ASSERT_TRUE(referenceConstellation >= GnssConstellationType::UNKNOWN &&
-                        referenceConstellation >= GnssConstellationType::IRNSS);
+                        referenceConstellation <= GnssConstellationType::IRNSS);
             ASSERT_TRUE(carrierFrequencyHz > 0);
             ASSERT_TRUE(codeType != "");
 
@@ -154,6 +154,85 @@
 }
 
 /*
+ * TestGnssAntennaInfo:
+ * Sets a GnssAntennaInfoCallback, waits for report, and verifies
+ * 1. phaseCenterOffsetCoordinateMillimeters is valid
+ * 2. phaseCenterOffsetCoordinateUncertaintyMillimeters is valid.
+ * PhaseCenterVariationCorrections and SignalGainCorrections are optional.
+ */
+TEST_P(GnssHalTest, TestGnssAntennaInfo) {
+    const int kAntennaInfoTimeoutSeconds = 2;
+
+    auto gnssAntennaInfo = gnss_hal_->getExtensionGnssAntennaInfo();
+    ASSERT_TRUE(gnssAntennaInfo.isOk());
+
+    // Skip test if GnssAntennaInfo v2.1 is not supported
+    sp<IGnssAntennaInfo> iGnssAntennaInfo = gnssAntennaInfo;
+    if (!(gnss_cb_->last_capabilities_ & IGnssCallback_2_1::Capabilities::ANTENNA_INFO) ||
+        iGnssAntennaInfo == nullptr) {
+        ALOGD("GnssAntennaInfo v2.1 is not supported.");
+        return;
+    }
+
+    sp<GnssAntennaInfoCallback> callback = new GnssAntennaInfoCallback();
+    auto result = iGnssAntennaInfo->setCallback(callback);
+    ASSERT_TRUE(result.isOk());
+    EXPECT_EQ(result, IGnssAntennaInfo::GnssAntennaInfoStatus::SUCCESS);
+
+    hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo> antennaInfos;
+    ASSERT_TRUE(callback->antenna_info_cbq_.retrieve(antennaInfos, kAntennaInfoTimeoutSeconds));
+    EXPECT_EQ(callback->antenna_info_cbq_.calledCount(), 1);
+    ASSERT_TRUE(antennaInfos.size() > 0);
+
+    for (auto antennaInfo : antennaInfos) {
+        // Remaining fields are optional
+        if (antennaInfo.phaseCenterVariationCorrectionMillimeters != NULL) {
+            int numRows = antennaInfo.phaseCenterVariationCorrectionMillimeters.size();
+            int numColumns = antennaInfo.phaseCenterVariationCorrectionMillimeters[0].row.size();
+            // Must have at least 1 row and 2 columns
+            ASSERT_TRUE(numRows >= 1 && numColumns >= 2);
+
+            // Corrections and uncertainties must have same dimensions
+            ASSERT_TRUE(antennaInfo.phaseCenterVariationCorrectionMillimeters.size() ==
+                        antennaInfo.phaseCenterVariationCorrectionUncertaintyMillimeters.size());
+            ASSERT_TRUE(
+                    antennaInfo.phaseCenterVariationCorrectionMillimeters[0].row.size() ==
+                    antennaInfo.phaseCenterVariationCorrectionUncertaintyMillimeters[0].row.size());
+
+            // Must be rectangular
+            for (auto row : antennaInfo.phaseCenterVariationCorrectionMillimeters) {
+                ASSERT_TRUE(row.row.size() == numColumns);
+            }
+            for (auto row : antennaInfo.phaseCenterVariationCorrectionUncertaintyMillimeters) {
+                ASSERT_TRUE(row.row.size() == numColumns);
+            }
+        }
+        if (antennaInfo.signalGainCorrectionDbi != NULL) {
+            int numRows = antennaInfo.signalGainCorrectionDbi.size();
+            int numColumns = antennaInfo.signalGainCorrectionUncertaintyDbi[0].row.size();
+            // Must have at least 1 row and 2 columns
+            ASSERT_TRUE(numRows >= 1 && numColumns >= 2);
+
+            // Corrections and uncertainties must have same dimensions
+            ASSERT_TRUE(antennaInfo.signalGainCorrectionDbi.size() ==
+                        antennaInfo.signalGainCorrectionUncertaintyDbi.size());
+            ASSERT_TRUE(antennaInfo.signalGainCorrectionDbi[0].row.size() ==
+                        antennaInfo.signalGainCorrectionUncertaintyDbi[0].row.size());
+
+            // Must be rectangular
+            for (auto row : antennaInfo.signalGainCorrectionDbi) {
+                ASSERT_TRUE(row.row.size() == numColumns);
+            }
+            for (auto row : antennaInfo.signalGainCorrectionUncertaintyDbi) {
+                ASSERT_TRUE(row.row.size() == numColumns);
+            }
+        }
+    }
+
+    iGnssAntennaInfo->close();
+}
+
+/*
  * TestGnssSvInfoFields:
  * Gets 1 location and a GnssSvInfo, and verifies
  * 1. basebandCN0DbHz is valid.
diff --git a/gnss/common/utils/default/Utils.cpp b/gnss/common/utils/default/Utils.cpp
index 0cdc865..2e5b873 100644
--- a/gnss/common/utils/default/Utils.cpp
+++ b/gnss/common/utils/default/Utils.cpp
@@ -235,6 +235,58 @@
     return svInfo;
 }
 
+hidl_vec<GnssAntennaInfo> Utils::getMockAntennaInfos() {
+    GnssAntennaInfo mockAntennaInfo_1 = {
+            .carrierFrequencyMHz = 123412.12,
+            .phaseCenterOffsetCoordinateMillimeters = Coord{.x = 1,
+                                                            .xUncertainty = 0.1,
+                                                            .y = 2,
+                                                            .yUncertainty = 0.1,
+                                                            .z = 3,
+                                                            .zUncertainty = 0.1},
+            .phaseCenterVariationCorrectionMillimeters =
+                    {
+                            Row{hidl_vec<double>{1, -1, 5, -2, 3, -1}},
+                            Row{hidl_vec<double>{-2, 3, 2, 0, 1, 2}},
+                            Row{hidl_vec<double>{1, 3, 2, -1, -3, 5}},
+                    },
+            .phaseCenterVariationCorrectionUncertaintyMillimeters =
+                    {
+                            Row{hidl_vec<double>{0.1, 0.2, 0.4, 0.1, 0.2, 0.3}},
+                            Row{hidl_vec<double>{0.3, 0.2, 0.3, 0.6, 0.1, 0.1}},
+                            Row{hidl_vec<double>{0.1, 0.1, 0.4, 0.2, 0.5, 0.3}},
+                    },
+            .signalGainCorrectionDbi =
+                    {
+                            Row{hidl_vec<double>{2, -3, 1, -3, 0, -4}},
+                            Row{hidl_vec<double>{1, 0, -4, 1, 3, -2}},
+                            Row{hidl_vec<double>{3, -2, 0, -2, 3, 0}},
+                    },
+            .signalGainCorrectionUncertaintyDbi =
+                    {
+                            Row{hidl_vec<double>{0.3, 0.1, 0.2, 0.6, 0.1, 0.3}},
+                            Row{hidl_vec<double>{0.1, 0.1, 0.5, 0.2, 0.3, 0.1}},
+                            Row{hidl_vec<double>{0.2, 0.4, 0.2, 0.1, 0.1, 0.2}},
+                    },
+    };
+
+    GnssAntennaInfo mockAntennaInfo_2 = {
+            .carrierFrequencyMHz = 532324.23,
+            .phaseCenterOffsetCoordinateMillimeters = Coord{.x = 5,
+                                                            .xUncertainty = 0.1,
+                                                            .y = 6,
+                                                            .yUncertainty = 0.1,
+                                                            .z = 7,
+                                                            .zUncertainty = 0.1},
+    };
+
+    hidl_vec<GnssAntennaInfo> mockAntennaInfos = {
+            mockAntennaInfo_1,
+            mockAntennaInfo_2,
+    };
+    return mockAntennaInfos;
+}
+
 }  // namespace common
 }  // namespace gnss
 }  // namespace hardware
diff --git a/gnss/common/utils/default/include/Utils.h b/gnss/common/utils/default/include/Utils.h
index e0c61a4..d9ad5a5 100644
--- a/gnss/common/utils/default/include/Utils.h
+++ b/gnss/common/utils/default/include/Utils.h
@@ -33,6 +33,9 @@
 using GnssSvInfoV1_0 = V1_0::IGnssCallback::GnssSvInfo;
 using GnssSvInfoV2_0 = V2_0::IGnssCallback::GnssSvInfo;
 using GnssSvInfoV2_1 = V2_1::IGnssCallback::GnssSvInfo;
+using GnssAntennaInfo = ::android::hardware::gnss::V2_1::IGnssAntennaInfoCallback::GnssAntennaInfo;
+using Row = ::android::hardware::gnss::V2_1::IGnssAntennaInfoCallback::Row;
+using Coord = ::android::hardware::gnss::V2_1::IGnssAntennaInfoCallback::Coord;
 
 struct Utils {
     static GnssDataV2_0 getMockMeasurementV2_0();
@@ -46,6 +49,7 @@
     static GnssSvInfoV1_0 getMockSvInfoV1_0(int16_t svid, V1_0::GnssConstellationType type,
                                             float cN0DbHz, float elevationDegrees,
                                             float azimuthDegrees);
+    static hidl_vec<GnssAntennaInfo> getMockAntennaInfos();
 };
 
 }  // namespace common