Johnston Co. P25 System questions

[BCasto]

For the first time I was in a spot where I could monitor the Johnston County P25 Phase 2 system, specifically site 3-Clayton and site 5-Archers Lodge.

I used Unitrunker and Pro96Com to capture site information. It seems site 3 is Phase 1 and site 5 is phase 2.

1- The call sign captured on both sites was PGU0%B?. Can this be right?

2- I got multiple LCNs on every frequency. For example 853.9875 has an LCN for its control channel function and a couple more for voice function. Is that a problem because my scanner is not Phase 2 compatible? The same situation occurred on both sites.

3- What is LRA? Site 3 had an LRA of 3 and site 5 had an LRA of 5. Seems obvious but I am not sure..

4- I am used to seeing MFID of Motorola. These sites had M/A-COM. What is that?

5- I am used to seeing channel access of P1 on the VIPER sites. On site 5 here the channel access is P2. Can someone explain what this means?

Thanks for your help.

 

[INDY72]

Its Harris system which used to be Tyco M/A Com which used to be GE/ Ericsson . All freqs are cc and voice. All rotate.

Sent from my LG-K330 using Tapatalk

 

[troymail]

If the system is Phase 2 - more specifically, if any talkgroups are Phase 2, then all sites are going to be Phase 2. There may be some talkgroups that are fulltime (still) Phase 1 and, if enabled, any talkgroup could temporarily revert to Phase 1 to support mutual aid (out of county unit) responses in Johnston County. Some systems have intentionally for various reasons made non-critical talkgroups (i.e. the landfill, etc.) TDMA (Phase 2) while keeping critical public safety talkgroups FDMA (Phase 1). My guess is they are trying to build confidence on Phase 2 before switching all users over.

Pro96Com provides a "flavor" of Phase 1 or Phase 2 but this isn't always accurate. I assume Pro96Com uses what it sees in the control channel stream to make this determination and if so, it is probably affected by the lack of Phase 2 users at any given time but I just don't know for sure how it works.

The callsign broadcast could be anything including no broadcast. It simply depends on the admins with setup and manage the system. On the other hand, this could be a garble but that is unlikely - particularly if you saw it more than once and/or on more than one site.

LCN? I don't think that applies much to a P25 system (from a scanner user perspective anyway) unless it is using a non-standard bandplan (which is possible). On the other hand, bandplans typically use lookup tables/calculations to determine which frequencies the transmission will use so I can see where an LCN might appear in the data... it's just not all that important in most cases on a P25 system (unlike with DMR, LTR, etc.)

LRA - must be a Unitrunker thing.... not sure I've ever seen that.

P25 systems are generally required (I believe before qualifying for federal funding) to be able to handle radios/equipment from multiple vendors - Motorola, MA/COM, Harris, EJ Johnson, etc.

P1? P2? Again, is this something seen on Unitrunker? I can only assume there are more references to Phase 1 or Phase 2 -- but I'm not sure I understand the comment/question.

 

[troymail]

BTW - you may want to ask decoding software (Pro96Com, Unitrunker, etc.) questions over in that forum:

https://forums.radioreference.com/voice-control-channel-decoding-software/

Be sure to be specific on not only what you are seeing but where (which program).

 

[BCasto]

Thanks to both MILF and TroyMail. I appreciate the response and insight. It is impressive the depth and breadth of knowledge the responding faithful have.

 

[BCasto]

So, I have been doing some traveling and visiting more sites (Viper and others). Running both Unitrunker and Pro96Com on each site. It is working pretty well and I have submitted some changes to the DB. Maybe I am odd, but I sort of enjoy it.