LDS trunk System

[gldavis]

I have been decoding this system (Site 03-Farnsworth Peak) with Unitrunker (not v02), and am a bit confused. Unitrunker is show it as what I believe is a P25 Phase 2 system. Most freqs are decoding with three LCN. Example 858.8125 shows LCNs 08-1241, 08-1240, and 00-0620. Some of the freqs are showing only 2 LCNs (at this time).
I reset my SDS-100 for this system as "P25 X2-TDMA", and it is following fine, now.
Can you have 3 LCNs for 1 freq?

 

[nd5y]

All of the P25 Phase II systems in my area are like that.
Phase I channels have a band plan/LCN numbering that starts with 00.
Phase II channels have a band plan/LCN numbering that starts with 08.
Each TDMA time slot has a separate LCN so each TDMA capable channel has two consecutive numbered LCNs that start with 08.
That means each RF channel usually has three LCNs.

 

[gldavis]

That makes sense. Thank-You. So the LCNs that start with 00 are more of a placeholder, and not used for traffic, in a Phase II system? Or that just not matter to a scanner?

 

[nd5y]

The scanner should get the band plans from the control channel.
I don't know anything about the particular system you are talking about so I don't know how it is configured.

Unless this system is brand new or was recently upgraded all the control channels are phase I and use the 00 band plan. If any of the talkgroups are phase I they will also use the 00 band plan.

If you run Unitrunker on it long enough you should log one 00 LCN and two 08 LCNs on each RF channel,
but that could vary depening on:
If any talkgroups phase I or are all talkgroups phase II.
If the control channel rotates to all frequencies or if the control channel data tells Unitrunker to populate all other channels as alternate control channels.

 

[kirkco]

I decoded this one a few years back when they upgraded. LCN's are not relevant for the SDSxxx, nor is a band plan for this system. You just need a control channel (but the control channel changes often on this system, so I program all the frequencies into my scanner). I program as P25 Trunk (not X2TDMA) and it works just fine.

 

[gldavis]

It looks like the control channels are on 00 LCNs, and traffic is on 08 LCNs. With public venues opening up, traffic is slowly increasing on this system. Still mainly Security, and Distribution Center Ops, with some housekeeping (custodial/maintenance).
I did have the SDS100 programed as P25 trunk, and noticed I was missing traffic. I deleted the system and reentered as X2TDNA, and it works better now.

 

[theaton]

The BYU site (7.7) is its own neighbor!