diff --git a/current.txt b/current.txt
index 8230852d95..908ecc4ed2 100644
--- a/current.txt
+++ b/current.txt
@@ -772,7 +772,7 @@ a64467bae843569f0d465c5be7f0c7a5b987985b55a3ef4794dd5afc68538650 android.hardwar
 e042522daa4b5f7fd4a0a19bcdadb93c79a1b04c09ef2c9813a3a8941032f3f5 android.hardware.contexthub@1.0::IContexthub
 c2f64133b83ede65c9939ef97ab5bd867b73faf3dba0e7e69f77c3c43d9e487e android.hardware.contexthub@1.0::IContexthubCallback
 bda492ec4021d13869de72bd6f8c15c5837b78d6136b8d538efec5320573a5ec android.hardware.gnss@1.0::IGnssMeasurementCallback
-6a271e493907e8ba20912e42771bd0d99ae45431a851d5675ef9496d02510a34 android.hardware.gnss@1.1::IGnssMeasurementCallback
+7ae2025662e30e690a3ffa1c65cc972c6297a68638174055c33cbf3d2e4bbddc android.hardware.gnss@1.1::IGnssMeasurementCallback
 11e9e1a1fd0c9b3d9648750d4b10dc2a839d3a6688904c3fc49500a4e7ca75b0 android.hardware.gnss@2.1::IGnssMeasurementCallback
 2c331a9605f3a08d9c1e0a36169ca57758bc43c11a78ef3f3730509885e52c15 android.hardware.graphics.composer@2.4::IComposerClient
 3da3ce039247872d95c6bd48621dbfdfa1c2d2a91a90f257862f87ee2bc46300 android.hardware.health@2.1::types
diff --git a/gnss/1.1/IGnssMeasurementCallback.hal b/gnss/1.1/IGnssMeasurementCallback.hal
index 36841ee0e6..f94c67a8ea 100644
--- a/gnss/1.1/IGnssMeasurementCallback.hal
+++ b/gnss/1.1/IGnssMeasurementCallback.hal
@@ -24,13 +24,38 @@ interface IGnssMeasurementCallback extends @1.0::IGnssMeasurementCallback {
      * Flags indicating the Accumulated Delta Range's states.
      *
      * See the table below for a detailed interpretation of each state. This is
-     * a continuation of the table from 1.1/IGnssMeasurementCallback.hal.
+     * a continuation of the table from 1.0/IGnssMeasurementCallback.hal.
      *
      * +---------------------+-------------------+-----------------------------+
      * | ADR_STATE           | Time of relevance | Interpretation              |
      * +---------------------+-------------------+-----------------------------+
      * | HALF_CYCLE_RESOLVED | ADR(t)            | Half cycle ambiguity is     |
      * |                     |                   | resolved at time t.         |
+     * |                     |                   |                             |
+     * |                     |                   | For signals that have       |
+     * |                     |                   | databits, the carrier phase |
+     * |                     |                   | tracking loops typically    |
+     * |                     |                   | use a costas loop           |
+     * |                     |                   | discriminator. This type of |
+     * |                     |                   | tracking loop introduces a  |
+     * |                     |                   | half-cycle ambiguity that   |
+     * |                     |                   | is resolved by searching    |
+     * |                     |                   | through the received data   |
+     * |                     |                   | for known patterns of       |
+     * |                     |                   | databits (e.g. GPS uses the |
+     * |                     |                   | TLM word) which then        |
+     * |                     |                   | determines the polarity of  |
+     * |                     |                   | the incoming data and       |
+     * |                     |                   | resolves the half-cycle     |
+     * |                     |                   | ambiguity.                  |
+     * |                     |                   |                             |
+     * |                     |                   | Before the half-cycle       |
+     * |                     |                   | ambiguity has been resolved |
+     * |                     |                   | it is possible that the     |
+     * |                     |                   | ADR_STATE_VALID flag is     |
+     * |                     |                   | set, but the ADR_STATE_     |
+     * |                     |                   | HALF_CYCLE_RESOLVED flag is |
+     * |                     |                   | not set.                    |
      * +---------------------+-------------------+-----------------------------+
      */
     enum GnssAccumulatedDeltaRangeState
diff --git a/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl b/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
index 58f29c5f92..efecddd41e 100644
--- a/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
+++ b/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
@@ -438,6 +438,31 @@ parcelable GnssMeasurement {
      * +---------------------+-------------------+-----------------------------+
      * | HALF_CYCLE_RESOLVED | ADR(t)            | Half cycle ambiguity is     |
      * |                     |                   | resolved at time t.         |
+     * |                     |                   |                             |
+     * |                     |                   | For signals that have       |
+     * |                     |                   | databits, the carrier phase |
+     * |                     |                   | tracking loops typically    |
+     * |                     |                   | use a costas loop           |
+     * |                     |                   | discriminator. This type of |
+     * |                     |                   | tracking loop introduces a  |
+     * |                     |                   | half-cycle ambiguity that   |
+     * |                     |                   | is resolved by searching    |
+     * |                     |                   | through the received data   |
+     * |                     |                   | for known patterns of       |
+     * |                     |                   | databits (e.g. GPS uses the |
+     * |                     |                   | TLM word) which then        |
+     * |                     |                   | determines the polarity of  |
+     * |                     |                   | the incoming data and       |
+     * |                     |                   | resolves the half-cycle     |
+     * |                     |                   | ambiguity.                  |
+     * |                     |                   |                             |
+     * |                     |                   | Before the half-cycle       |
+     * |                     |                   | ambiguity has been resolved |
+     * |                     |                   | it is possible that the     |
+     * |                     |                   | ADR_STATE_VALID flag is     |
+     * |                     |                   | set, but the ADR_STATE_     |
+     * |                     |                   | HALF_CYCLE_RESOLVED flag is |
+     * |                     |                   | not set.                    |
      * +---------------------+-------------------+-----------------------------+
      */
     const int ADR_STATE_UNKNOWN = 0;