diff --git a/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.c b/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.c
index e45d8b0..304348b 100644
--- a/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.c
+++ b/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.c
@@ -152,6 +152,8 @@ static uint16_t clamp_measure_delay_us(uint16_t delay_us)
 #define BLE_RDB_HEADER_LEN      8       /* "rdb:" tag(4) + num_samples(2) + compressed_size(2) */
 #define BLE_REB_DATA_LEN        (BLE_MTU_SIZE - BLE_REB_HEADER_LEN)   /* 238 bytes = 119 samples */
 #define BLE_RED_DATA_LEN        (BLE_MTU_SIZE - BLE_RED_HEADER_LEN)   /* 238 bytes = 119 samples */
+#define MAA_REB_HEADER_LEN      8       /* "reb:" tag(4) + ch_info(2) + num_samples(2) */
+#define MAA_REB_DATA_LEN        (BLE_MTU_SIZE - MAA_REB_HEADER_LEN)   /* 236 bytes = 118 samples */
 #define BLE_PACKET_DELAY_MS     100     /* Inter-packet delay - allow BLE TX buffer to drain */
 /* maa_async: inter-packet busy-wait (0 = rely on BLE_NUS_EVT_TX_RDY only). */
 #define MAA_ASYNC_POST_REB_MS   0U
@@ -1162,6 +1164,7 @@ dr_adc_err_t dr_adc_transmit_channel_delta(const dr_maa_channel_t *ch_data, uint
 
 /* Global async context */
 static maa_async_ctx_t g_maa_ctx = { .state = MAA_ASYNC_IDLE };
+static uint8_t g_maa_ch_session = 0;
 
 /* (reb+red merged protocol) */
 
@@ -1202,7 +1205,8 @@ static dr_adc_err_t maa_async_capture_channel(uint8_t ch)
 /**
  * @brief Send reb: header + data merged for current channel
  *
- * reb: tag(4) + num_samples(2) + data(up to 238 bytes)
+ * reb: tag(4) + ch_info(2) + num_samples(2) + data(up to 236 bytes)
+ * ch_info: session(1) + channel(1)
  * If <= 100 samples (200B), the channel completes in this single packet
  */
 static bool maa_async_send_header(void)
@@ -1212,16 +1216,23 @@ static bool maa_async_send_header(void)
     uint32_t tx_err;
 
     uint16_t total_data_bytes = ch->num_samples * 2;
+    uint16_t ch_info = ((uint16_t)g_maa_ctx.ch_session << 8) | g_maa_ctx.current_ch;
 
-    /* reb: header + data merged (Big-Endian) */
+    /* reb: header + channel info + data merged (Big-Endian) */
     buf[0] = 'r'; buf[1] = 'e'; buf[2] = 'b'; buf[3] = ':';
-    buf[4] = (uint8_t)(ch->num_samples >> 8);
-    buf[5] = (uint8_t)(ch->num_samples & 0xFF);
+    buf[4] = (uint8_t)(ch_info >> 8);
+    buf[5] = (uint8_t)(ch_info & 0xFF);
+    buf[6] = (uint8_t)(ch->num_samples >> 8);
+    buf[7] = (uint8_t)(ch->num_samples & 0xFF);
+    ADC_LOG("reb ch_info: session=%u, ch=%u, value=0x%04X",
+            g_maa_ctx.ch_session,
+            g_maa_ctx.current_ch,
+            ch_info);
 
-    uint16_t dst_idx = BLE_REB_HEADER_LEN;
-    uint16_t first_chunk = (total_data_bytes > BLE_REB_DATA_LEN) ? BLE_REB_DATA_LEN : total_data_bytes;
+    uint16_t dst_idx = MAA_REB_HEADER_LEN;
+    uint16_t first_chunk = (total_data_bytes > MAA_REB_DATA_LEN) ? MAA_REB_DATA_LEN : total_data_bytes;
     uint16_t src_idx = 0;
-    while (src_idx < ch->num_samples && (dst_idx - BLE_REB_HEADER_LEN) < first_chunk)
+    while (src_idx < ch->num_samples && (dst_idx - MAA_REB_HEADER_LEN) < first_chunk)
     {
         uint16_t sample = ch->samples[src_idx++];
         buf[dst_idx++] = (uint8_t)(sample >> 8);
@@ -1376,6 +1387,7 @@ dr_adc_err_t maa_async_start(uint8_t freq_option, uint16_t delay_us, uint16_t nu
     g_maa_ctx.ble_buffer = ble_buffer;
     g_maa_ctx.current_ch = 0;
     g_maa_ctx.current_pkt = 0;
+    g_maa_ctx.ch_session = g_maa_ch_session++;
     g_maa_ctx.data_offset = 0;
     g_maa_ctx.on_complete_cb = NULL;  /* default: no callback (maa?) */
 
diff --git a/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.h b/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.h
index ef31687..dddfe80 100644
--- a/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.h
+++ b/project/ble_peripheral/ble_app_bladder_patch/measurement/adc121s051/dr_adc121s051.h
@@ -434,6 +434,7 @@ typedef struct {
     maa_async_state_t state;      /**< Current state */
     uint8_t     current_ch;       /**< Current channel (0~7) */
     uint8_t     current_pkt;      /**< Current packet index */
+    uint8_t     ch_session;       /**< reb: channel session id for one measurement set */
     uint16_t    data_offset;      /**< Bytes sent so far for current channel */
     uint8_t     freq_option;      /**< Frequency option */
     uint16_t    delay_us;         /**< Capture delay */