P25 X2 Technical Specifications

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Bigfella237
Posts: 152
Joined: Wed May 02, 2012 11:30 am

P25 X2 Technical Specifications

Post 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
Karl NVW
Posts: 174
Joined: Wed Sep 03, 2003 7:13 am

Re: P25 X2 Technical Specifications

Post 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.
Karl - WA8NVW AFA5VB
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d119
Posts: 3532
Joined: Tue Mar 19, 2002 4:00 pm

Re: P25 X2 Technical Specifications

Post 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.
Karl NVW
Posts: 174
Joined: Wed Sep 03, 2003 7:13 am

Re: P25 X2 Technical Specifications

Post 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!
Karl - WA8NVW AFA5VB
SHARES + NCS
Bigfella237
Posts: 152
Joined: Wed May 02, 2012 11:30 am

Re: P25 X2 Technical Specifications

Post 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.
MattSR
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Joined: Mon Apr 21, 2003 10:00 pm

Re: P25 X2 Technical Specifications

Post by MattSR »

It was 64 bit.
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