Hytera IPSC Sync dissection and documentation

Author: smarek

okdmr/dmrlib/hytera/hytera_ipsc_sync.py

@@ -14,21 +14,46 @@ def __init__(
         Hytera IPSC sync packet is different, not dmr data,
         it does not contain EMB or SLOT PDUs, ending might be some RCP / HRNP / HDAP or different hytera-specific protocol
 
-        example payload:    0000 0000 0000 [0000 0000 006f] [0023 0037 00fa] 2a34 102c 2a94 102c 2af4 102c 2e01 4f83
+        example full frame:
+        5a5a5a5a0000000042000501010000001111eeee555511114000000000000000000000006f0023003700fa00000000000000000000000000834f00c3e20801006f000000fa372300
 
-        contains 16-bit fields
-        [00 00]
-        [00 00]
-        [00 00]
+        dissected:
+        [5a 5a 5a 5a] - fixed header
+        [00] - sequence number
+        [00 00 00] - unknown data (3 bytes)
+        [42] - packet type
+        [00 05 01 01 00 00 00] - unknown data (7 bytes)
+        [11 11] - timeslot "1" in this case, [22 22] means TS2
+        [EE EE] - slot type - "SYNC" in this case
+        [55 55] - color code "5"
+        [11 11] - frame type - "voice sync" in this case
+        [40 00 E2 08] - unknown data (4 bytes)
+        [01] - call type - "group call" in this case, 00 means "private call"
+
+        --- IPSC DMR Data payload begin ---
+
+        [00 00 00 00 00] - unknown data (5 bytes)
 
         [00 00] \
-        [00 00]  =>  these 3 identify source radio/repeater, (16)[00006F] == (10)[111]
+        [00 00]  =>  these 3 identify destination radio/repeater, (16)[00006F] == (10)[111]
         [00 6F] /
 
         [00 23] \
-        [00 37]  =>  these 3 identify destination radio/repeater, (16)[2337FA] == (10)[2308090]
+        [00 37]  =>  these 3 identify source radio/repeater, (16)[2337FA] == (10)[2308090]
         [00 FA] /
 
+        [ 13 times 00 ] - unknown data (13 bytes)
+        [83 4F 00 C3] - unknown data (4 bytes), possible signature, checksum or similar
+
+        --- IPSC DMR Data payload end ---
+
+        [E2 08 01] - unknown data, but matches end of "unknown data (4 bytes) and call type" fields from before payload
+
+        [00 6F 00 00] -> U4LE destination radio/repeater, (16)[00006F] == (10)[111]
+        [00 FA 37 23] -> U4LE source radio/repeater, (16)[2337FA] == (10)[2308090]
+
+        [00] - unknown data (1 byte)
+
         """
         super().__init__(full_bits, burst_type)
         self.has_emb = False