diff --git a/gnss/1.0/IGnssNavigationMessageCallback.hal b/gnss/1.0/IGnssNavigationMessageCallback.hal
new file mode 100644
index 0000000..a714fd7
--- /dev/null
+++ b/gnss/1.0/IGnssNavigationMessageCallback.hal
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2016 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@1.0;
+
+/** Represents a GNSS navigation message (or a fragment of it). */
+interface IGnssNavigationMessageCallback {
+    /*
+     * Enumeration of available values to indicate the GNSS Navigation message
+     * types.
+     *
+     * For convenience, first byte is the GnssConstellationType on which that signal
+     * is typically transmitted.
+     */
+    enum GnssNavigationMessageType : int16_t {
+        TYPE_UNKNOWN    = 0,
+        /** GNSS L1 C/A message contained in the structure.  */
+        GNSS_L1CA       = 0x0101,
+        /** GNSS L2-CNAV message contained in the structure. */
+        GNSS_L2CNAV     = 0x0102,
+        /** GNSS L5-CNAV message contained in the structure. */
+        GNSS_L5CNAV     = 0x0103,
+        /** GNSS CNAV-2 message contained in the structure. */
+        GNSS_CNAV2      = 0x0104,
+        /** Glonass L1 CA message contained in the structure. */
+        GLO_L1CA        = 0x0301,
+        /** Beidou D1 message contained in the structure. */
+        BDS_D1          = 0x0501,
+        /** Beidou D2 message contained in the structure. */
+        BDS_D2          = 0x0502,
+        /** Galileo I/NAV message contained in the structure. */
+        GAL_I           = 0x0601,
+        /** Galileo F/NAV message contained in the structure. */
+        GAL_F           = 0x0602
+    };
+
+    /*
+     * Status of Navigation Message
+     * When a message is received properly without any parity error in its
+     * navigation words, the status must be set to PARITY_PASSED. But if a message is
+     * received with words that failed parity check, but GNSS is able to correct
+     * those words, the status must be set to PARITY_REBUILT.
+     * No need to send any navigation message that contains words with parity error
+     * and cannot be corrected.
+     */
+    enum NavigationMessageStatus : uint16_t {
+        PARITY_PASSED  = (1 << 0),
+        PARITY_REBUILT = (1 << 1),
+        STATUS_UNKOWN  = 0
+    };
+
+    struct GnssNavigationMessage {
+        /*
+         * Satellite vehicle ID number, as defined in GnssSvInfo::svid
+         * This is a mandatory value.
+         */
+        int16_t svid;
+
+        /*
+         * The type of message contained in the structure.
+         * This is a mandatory value.
+         */
+        GnssNavigationMessageType type;
+
+        /*
+         * The status of the received navigation message.
+         * No need to send any navigation message that contains words with parity
+         * error and cannot be corrected.
+         */
+        NavigationMessageStatus status;
+
+        /*
+         * Message identifier. It provides an index so the complete Navigation
+         * Message can be assembled.
+         *
+         * - For GNSS L1 C/A subframe 4 and 5, this value corresponds to the 'frame
+         *   id' of the navigation message, in the range of 1-25 (Subframe 1, 2, 3
+         *   does not contain a 'frame id' and this value can be set to -1.)
+         *
+         * - For Glonass L1 C/A, this refers to the frame ID, in the range of 1-5.
+         *
+         * - For BeiDou D1, this refers to the frame number in the range of 1-24
+         *
+         * - For Beidou D2, this refers to the frame number, in the range of 1-120
+         *
+         * - For Galileo F/NAV nominal frame structure, this refers to the subframe
+         *   number, in the range of 1-12
+         *
+         * - For Galileo I/NAV nominal frame structure, this refers to the subframe
+         *   number in the range of 1-24
+         */
+        int16_t messageId;
+
+        /*
+         * Sub-message identifier. If required by the message 'type', this value
+         * contains a sub-index within the current message (or frame) that is being
+         * transmitted.
+         *
+         * - For GNSS L1 C/A, BeiDou D1 & BeiDou D2, the submessage id corresponds to
+         *   the subframe number of the navigation message, in the range of 1-5.
+         *
+         * - For Glonass L1 C/A, this refers to the String number, in the range from
+         *   1-15
+         *
+         * - For Galileo F/NAV, this refers to the page type in the range 1-6
+         *
+         * - For Galileo I/NAV, this refers to the word type in the range 1-10+
+         */
+        int16_t submessageId;
+
+        /*
+         * The data of the reported GNSS message. The bytes (or words) are specified
+         * using big endian format (MSB first). The data is stored and decoded
+         * in a server for research purposes.
+         *
+         * - For GNSS L1 C/A, Beidou D1 & Beidou D2, each subframe contains 10 30-bit
+         *   words. Each word (30 bits) must fit into the last 30 bits in a
+         *   4-byte word (skip B31 and B32), with MSB first, for a total of 40
+         *   bytes, covering a time period of 6, 6, and 0.6 seconds, respectively.
+         *   The standard followed is 1995 SPS Signal specification.
+         *
+         * - For Glonass L1 C/A, each string contains 85 data bits, including the
+         *   checksum.  These bits must fit into 11 bytes, with MSB first (skip
+         *   B86-B88), covering a time period of 2 seconds.
+         *   The standard followed is Glonass Interface Control Document Edition 5.1.
+         *
+         * - For Galileo F/NAV, each word consists of 238-bit (sync & tail symbols
+         *   excluded). Each word must fit into 30-bytes, with MSB first (skip
+         *   B239, B240), covering a time period of 10 seconds. The standard
+         *   followed is European GNSS(Galileo) Signal in Space Interface
+         *   Control Document Issue 1.2.
+         *
+         * - For Galileo I/NAV, each page contains 2 page parts, even and odd, with
+         *   a total of 2x114 = 228 bits, (sync & tail excluded) that must fit
+         *   into 29 bytes, with MSB first (skip B229-B232). The standard followed
+         *   is same as above.
+         *
+         * TODO(b/32022567): Describe this relationship with data to the VTS
+         * via custom annotations and plug in a VTS test to verify that the data
+         * correctly follows the standard.
+         *
+         */
+        vec<uint8_t> data;
+    };
+
+    /*
+     * The callback to report an available fragment of a GNSS navigation messages
+     * from the HAL.
+     *
+     * @param message - The GNSS navigation submessage/subframe representation.
+     */
+     gnssNavigationMessageCb(GnssNavigationMessage message);
+};