Bossier Parish Fire/EMS - DMR System

[rattlerbb01]

Thought this deserved it's own thread.

So.....they have a networked conventional DMR system countywide. I have ID'd the following over the last few days:

Main "911" repeaters (dispatch is referred to as 911)

154.310 (Northeast) CC 10
155.265 (Northwest) CC 11
154.340 (Central) CC 12
155.550 (Southeast) CC 13

TG 110 is Fire and EMS main dispatch. EMS will always use this for response, and fire will be on here as well as their local talkgroup. Not sure if they are patched together or not.

154.445 (Central) CC 10, TG 124, SL 1 District 4 Ops (ENGINE 3 at the house on Swan Lake)
154.445 (Central) CC 10, TG 125, SL 2 District 4 Paging (sick calls, alarms)
155.010 (Southeast) CC 10, TG 121, SL 1 District 1 Ops (sick calls, command established)
155.010 (Southeast CC 10, TG 122, SL 2 District 1 Paging (sick calls)

I know there is more because the other repeaters buzz with static DMR time to time, but I have not caught voice or paging just yet. I have seen some weird stuff with the slots being both SL 1 on the Uniden 436HP for both TGs 121 and 122. I am not sure why this is, but my recommendation for setting this system up to monitor is as follows:

1.) Create a DMR one frequency trunk system in the 436/536 or SDS100/200
2.) Turn ID Search ON
3.) Create a individual site for each of the repeaters and name it something that tells you the frequency and location, i.e. "Northeast 154.310" and "Haughton 159.135"
4.) Enter the matching frequency for the site name in step 3. Leave the CC to search if it isn't already known by you or the database.
5.) Scan away.

This method lets you catch all the talkgroups just like it is a trunk system, and you can then go in and label them. This method has worked great for me with local school districts back home that use a lot of DMR, as well as big counties like Okmulgee in Oklahoma.

 

[rattlerbb01]

I'm really leaning toward this being a conventional networked system, and after a little more study, that might be the route I take in rebuilding this system. We are up to 5 towers used now for Parish 911 dispatch with 154.370 from Elm Grove found today with CC 14. All carry TG 110 for dispatch, but I've now found 3 additional talkgroups used on 154.340 alone:

TG 98, S1 - District 7 Fire/Medic 1 (Plain Dealing)
TG 112, S2 - District 7 Fire
TG 113, S2 - Northwest Medic 2 (Also Plain Dealing)

I'm also about to add 155.265 CC 11, TG 127, S2 as "North Bossier" as that is what Northwest Fire units called this particular group/tower.

I'm not sure how the architecture of systems like this works to where you can have multiple (more than 2) talkgroups with similar slots on the same repeaters, but I am trying to find some good research material on it.

 

[rattlerbb01]

159.135 TG 137 S1, didn’t get the CC yet. Haughton Fire Dept

they appear to be city only, as they are surrounded by District 1. Medic 3 responds for transport but both District 1 and HFD respond with service trucks or engines to sick calls.

I haven’t caught anything else yet, but I am confident enough to know that everything in the county outside of Bossier City limits is dispatched on TG 110 plus the local repeater for the district. EMS responds on either 110 or the local channel. I’m going to lock out 110 for the rest of my recordings since it takes the lions share of the air time. Still need Districts 2,5 and 7 to get a few more calls before I can verify any of their groups.

 

[rattlerbb01]

155.550 CC 13 TG 174 SL 1&2 Unknown keyups
155.265 CC 11 TG 130 SL 2 District 7 Fire Paging
155.265 CC 11 TG 78 SL 1 Unknown keyups
159.135 CC ?? TG 138 SL 1&2 Haughton Fire Paging
159.135 CC ?? TG 137 SL 1 Haughton Response/Ops
154.445 CC 7 TG 145 SL 2 Central Bossier Tactical
154.340 CC 12 TG 98 SL 1 Sprint 1 on scene
154.340 CC 12 TG 112 SL 2 FD 7 Medic 1 paging
154.340 CC 12 TG 113 SL 2 NW EMS Medic 2, 303 N Arkansas St
154.340 CC 12 TG 114 SL 2 FD 1 Medic 3 paging

I also found that I had incorrect notes on 155.010, it is CC 6. I have not caught Haughton's CC yet, only their talkgroups in recording mode. I also had two different CC's written down for 154.445, and I confirmed that the correct one for Bossier Parish is 7, not 10. 10 must be from a nearby parish or county that piped in on a band opening.

 

[rattlerbb01]

This morning I created the Bossier Parish Fire and EMS DMR conventional networked system based on the fact that the 5 repeaters that carry talkgroup 110 are all networked together and send data beacons for roaming radios. No way to tell for sure if radios can roam unless I could physically see their set up but that doesn't really matter for us using scanners as both sides of every transmission come across all towers simultaneously. I'm still not exactly sure if the network is set up so that only TG 110 can be networked or if others can be as well. I know that slot 2 on all those towers carries other traffic as well from multiple unique talkgroups.

I left the conventional repeaters alone that do not broadcast any beacons or carry non-unique talkgroups. If anyone has any good DMR information, please feel free to chime in. I've seen talkgroups 134, 135, 137 and 138 appear on both slot 1 and 2 so since I'm not DMR tech savvy as some I am not sure how that part works yet.

Interesting side note.....the north central and north ends appear to struggle with coverage even with 3 towers in the area, I'm guessing the tall pine trees do a number on them. District 5 frequently has to use North Bossier to get out and says as much when dispatch tells them on TG 110 that their signal is bad. District 4 responded to a couple grass fires northeast of Benton and had to tell everyone to swap to the tac channel to talk better, at which point they disappeared from towers, which implies they are capable of using simplex on scene, whether analog or digital.