Page 1 of 1

P25 X2 Technical Specifications

Posted: Sun Sep 28, 2014 5:23 am
by Bigfella237
I know P25 X2 is Motorola proprietary but does anyone know if there exists any technical specs for it similar to the TIA specs for P25 or ETSI specs for DMR?

Information on this protocol is extremely hard to come by but from what little I've seen P25 X2 appears to be very close in its design to DMR; both use the AMBE vocoder (like P25 Phase II); and both are 9600bps (unlike P25 Phase II which is 12000bps).

The main thing I'm trying to confirm, if anybody happens to know, is whether P25 X2 uses a 64-bit Message Indicator (MI) like P25, or a 32-bit MI like DMR?

If I had to guess, I'd say they stayed with the 64-bit MI as P25 Phase I had at the time, but the lower bitrate means space is tight, maybe this necessitated reducing the size of the MI to 32-bit?

Andrew

Re: P25 X2 Technical Specifications

Posted: Sat Apr 28, 2018 5:26 pm
by Karl NVW
It would have been 64 bit, but that won't matter since virtually ALL X2 radios were flashed up to real Phase 2 during rebanding. The only X2 radios still existing in the wild would be LSS.

Re: P25 X2 Technical Specifications

Posted: Wed May 16, 2018 7:27 am
by d119
Well lets first off not get terms confused. It's called X2 TDMA, not P25 X2... You're mixing flavors there. Don't forget about OBT radios, Karl.

Re: P25 X2 Technical Specifications

Posted: Wed May 16, 2018 1:01 pm
by Karl NVW
A valid point but since the original query was from 2014 I think we should leave this until the OP renews the request. I KNOW I should have!

Re: P25 X2 Technical Specifications

Posted: Wed May 16, 2018 1:17 pm
by Bigfella237
I am the OP and I'm still watching this thread, but I haven't done anything in this area of research for years and what little there were of X2 sites are long gone anyway.

I would still be interested to know just to satisfy my curiosity, but it's hardly relevant now.

Re: P25 X2 Technical Specifications

Posted: Tue Jun 19, 2018 5:24 pm
by MattSR
It was 64 bit.