Updating Columbus/Bartholomew IN Trunks

[JasonTracy]

There appear to be two trunked systems using frequencies licensed by City of Columbus in Bartholomew County, separate from the SAFE-T system.

There is the Columbus Public Safety system, which is in RadioReference but is missing quite a few talk groups. It is also backup for the SAFE-T system for city fire and police.
I think I've identified some CRH talkgroups, along with the juvenile services talkgroup. I'm going to keep recording and try to make sure before submitting them to RR.

However, I was hearing no BCSC traffic on there.

After some digging, I've found that 855.2125 has DMR voice traffic with quite a few talkgroups on it. I've identified two BCSC bus TG's, several that sound like schools, the city buses, trash trucks, and animal control.

From the sound of it, this is a second trunk system, but I've been unable to locate the control frequency, or determine if it is P25 or some other type of trunking.

Any pointers? I'm new to my TRX-1, and have not found a good way to search for control channels. I have a couple of cheap SDR's, but the noise floor is too high on them. I may try getting a better SDR, but if someone else has already done some of this work, I'd rather not duplicate efforts.

Thanks!
Jason
W9TCP

 

[INDY72]

Its all in the DB on the County Page.

https://www.radioreference.com/apps/db/?fccCallsign=WPNQ936
Conventional DMR for City of Columbus.
855.21250 WPNQ936 RM ClmbsSchools Columbus Schools DMR Schools
855.46250 WPJJ684 RM ClmbsSchools Columbus Schools DMR Schools
855.88750 WPJJ684 RM ClmbsSchools Columbus Schools DMR Schools


Log the Color Code, TGs in use, and Slots, then submit the findings and I will get it in the DB.

 

[JasonTracy]

milf, the confusing part is that I'm seeing conversations jump between 855.4625 and 855.2125. Same talk group.

Doesn't that require a control frequency of some sort to coordinate, like how P25 works? Or, can traditional DMR jump frequencies like that on its own?

Sorry, I'm new to DMR.

 

[INDY72]

On a conventional TRBO DMR multi repeater set up such as is in play here, all of them can share the same TGs. All 3 repeaters are part of the school system and share the users. Most likely they are IP Site Connect linked. An much larger set up like this is in use by IU Health at multiple facilities in Hamilton and Marion Counties ... In fact, they have multiple IP Site Connect TRBO Conventional repeaters, and 2 TRBO TRS systems sharing users between 6/7 facilities, and the IUPUI campus.

In your situation, you have 3 repeaters giving you 2 talk paths each. That is up to 6 available at any time. That can handle quite a few TGs, which means a lot of users. You can take a single HT, and program it for I believe up to 15 shared repeaters on an conventional IP Site Connect TRBO system and then just switch it to each repeater as needed. You only need control chan type functionality on an Trunked DMR system.

Also you have no control chan on conventional P25 systems either, only on trunked.

Check out the wiki for far more detailed info on DMR, and P25.

 

[JasonTracy]

Here is what I was about to submit through the form. I figure it was better to send here first, since I've not done a submission like this before, and would rather confirm that I've done the format right, first.

Under "Columbus":

Remove the following frequencies:
855.21250 WPNQ936 RM ClmbsSchools Columbus Schools DMR Schools
855.46250 WPJJ684 RM ClmbsSchools Columbus Schools DMR Schools
855.88750 WPJJ684 RM ClmbsSchools Columbus Schools DMR Schools

Modify (or delete) trunked system "Cummins". They are no longer using Motorola, all frequencies appear to be DMR with encryption with two sites, based off observation so far and FCC licenses. Sites as follows:

Columbus:
856.387500
855.437500
855.887500
855.162500
854.912500
860.362500

Seymour:
854.912500
860.362500

New DMR system "Columbus City DMR" (for want of a better name. This has both schools and non-public safety city groups).

Site 1: Carr Hill
855.212500
855.462500

Talkgroups:
TG,Alpha,Description
4,BCSC Bus 1,Bartholomew County School Corporation Bus 1
5,BCSC Bus 2,Bartholomew County School Corporation Bus 2
14,City Streets,Columbus Department of Public Works - Streets
15,City Sanitation,Columbus City Sanitation (Trash Trucks)
16,ColumBUS,Columbus City Transit Buses
20,Animal Control,Columbus City Animal Control

Modify the following talk groups for Columbus Public Safety (P25):
New category "Columbus Regional Health"
Move TG 264 to Columbus Regional Health.
Rename TG 264:
264,CRH Security,Columbus Regional Health Security

Add new TG to Columbus Regional Health:
265,CRH Ambulance,Columbus Regional Health Ambulance (not EMS)

New TG, can be under Jail Operations or new category (separate site, similar function. Jail for juveniles).
275,BC Juvenile,Bartholomew County Youth Services Center

 

[INDY72]

Go ahead with the sub and I will work things in. Also, I need the type for the new upgraded Cummins system. Is it an Con+, or Cap+ now? Color Codes? SysID ? LCNs?