What are your methods for identifying unknown talk groups?

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kk6yus

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Greetings all,

I am currently in the process of discovering and identifying talkgroups on a local trunked system (WNLU616 (CALIFORNIA, STATE OF) FCC Callsign Details)

This information in the RR database is outdated so I am trying to submit good info.

I've added a Wildcard to the talkgroups list so that any transmission is caught, but the result is lots of Talkgroup IDs (TGIDs).

What methods do people use to identify talkgroup descriptions once IDs are known in order to submit them to RR database? Does every talk group ID represent a channel? For example, a conversation between call sign "Dispatch" and "Alpha" shows TGIDs 1550 and 2500. Then a conversation between callsigns "Dispatch" and "Bravo" show TGIDs 1550 and 3500.

Does TGID 1550 correspond with a "Dispatch" channel?

Can programs such as Unitrunker identify the number of channels and TGIDs within a system based off the control channels commands?

I hope my question is clear enough.

- 73
 

chief21

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Please clarify. Are you talking about talkgroups or radio ID's? In the example by the OP, it appears to be discussing radio IDs rather than talkgroups.

Talkgroups (TGIDs) in a trunked radio system perform the same function as a conventional "channel"... a group of users often related to a particular purpose or function.

Radio ID's (RIDs) are the numbers assigned to a particular radio (or dispatch console).

To answer your question about Unitrunker - Yes. Unitrunker will dynamically display most of the data embedded in the control channel, to include frequency, talkgroup ID and radio ID for every transmission.
 

nd5y

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Can programs such as Unitrunker identify the number of channels and TGIDs within a system based off the control channels commands?
Yes, but there has to be affiliation (somebody has to switch to that talkgroup or talk on it) in order for Unitrunker to log it.
 

nd5y

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What methods do people use to identify talkgroup descriptions once IDs are known in order to submit them to RR database?
Sometimes it's easy if the system planners allocated blocks of contiguous talkgroup IDs to each user or agency.

Go to the database page. Click on List All in one table right below the list of frequencies. This sorts all the talkgroups in number order.
Look for patterns, holes, gaps in the numbers.

You might see something like:
10001 dispatch
10002 tac-1
10004 tac-3

You find new talkgroup 10003 and don't know what it is. It's probably tac-2.
 

troymail

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Greetings all,

I am currently in the process of discovering and identifying talkgroups on a local trunked system (WNLU616 (CALIFORNIA, STATE OF) FCC Callsign Details)

This information in the RR database is outdated so I am trying to submit good info.

I've added a Wildcard to the talkgroups list so that any transmission is caught, but the result is lots of Talkgroup IDs (TGIDs).

What methods do people use to identify talkgroup descriptions once IDs are known in order to submit them to RR database? Does every talk group ID represent a channel? For example, a conversation between call sign "Dispatch" and "Alpha" shows TGIDs 1550 and 2500. Then a conversation between callsigns "Dispatch" and "Bravo" show TGIDs 1550 and 3500.

Does TGID 1550 correspond with a "Dispatch" channel?

Can programs such as Unitrunker identify the number of channels and TGIDs within a system based off the control channels commands?

I hope my question is clear enough.

- 73
I'll start very basic...

Your radio (probably) and various tools like Unitrunker will provide you with various pieces of the puzzle. These might include:

TGID (talkgroup ID) - analogous to a conventional "channel" where the purpose of the "talkgroup" is many times (but not always) specific as in "dispatch" or a "tac" channel

RID (radio ID) - each radio typically (but not always) has a unique identifier on a given system which serves many purposes but mainly can help identify a specific user or "role" (many variations here)

FREQUENCY - RF frequency a talkgroup is assigned to from one call to the next

In your example, if 1500 is displaying as a "talkgroup" (TGID) and at the same time you see another ID (like 2500 or 3500) you're probably seeing radio 2500 talking and then radio 3500 talking on talkgroup 1500. Group/talkgroup calls are heard by everyone on that "talkgroup"(ID).

However, radios can also (depending on the system) call one another like a phone. These are known as "private calls" in the sense that only the to parties in the call hear the conversation and not everyone else on the system. So again, another possibility in your example would be radioID 1500 talking to radioID 2500 and then radioID 1500 talking to radioID 3500. However, since you are saying it said "TGID", will assuming 1500 is a TGID.

Labels or "alpha tags" like "Dispatch" are simply attributes or tags associated with an ID.

Unitrunker and your radio will provide "clues" but the real only way to know what a particular "TGID" is used for is to listen over time and make your best guess at what that talkgroup is. This could be easy - sometimes users will actually say the name of the talkgroup in either testing or real usage. Other times, you just have to base it on the activity you hear. The number of talkgroups may never be known or at least could take a long time. Many planned/programmed talkgroups rarely if ever get used - and others will appears over time and the system evolves.

It's ok to submit your best belief as to what the talkgroup is but it should be something a bit more specific than "law" or "police". Once you submit your info, more people will start listening (some don't search for new things using wildcards, etc and will wait until an identified or semi-identified talkgroup appears in the database. Others behind you will help further refine exactly what the talkgroup is - sometimes people that know the real name and purpose will chime in.

It's a community of scanner users providing the information. Collectively, we help to improve the information over time.
 

kk6yus

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Location
Central Valley, CA
Given all that has been said (and thank you for your responses), I must say I'm sure whether the values seen are TGIDs are Radio IDs.

Unfortunately I am waiting on a four-pin audio cable, so I am unable to use any decoding software yet.

What I do have is the software provided with the RS PRO-668. When reviewing audio files within the software, TGIDs and Radio IDs are shown. ( Imgur: The most awesome images on the Internet)

Is it possible Radio IDs are being populated in the TGID slot?

I still believe they are TGIDs as multiple call signs converse on a single "TGID," as shown by the PRO668 software.
 

troymail

Silent Key
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Supply (Lockwood Inlet area), NC
Given all that has been said (and thank you for your responses), I must say I'm sure whether the values seen are TGIDs are Radio IDs.

Unfortunately I am waiting on a four-pin audio cable, so I am unable to use any decoding software yet.

What I do have is the software provided with the RS PRO-668. When reviewing audio files within the software, TGIDs and Radio IDs are shown. ( Imgur: The most awesome images on the Internet)

Is it possible Radio IDs are being populated in the TGID slot?

I still believe they are TGIDs as multiple call signs converse on a single "TGID," as shown by the PRO668 software.
Is this the system?
California Substance Abuse Treatment Facility/California State Prison, Corcoran Trunking System, Corcoran, California - Scanner Frequencies

The easiest thing to do is to let the radio record wildcard hits for a while and then look at them in the PC software. It's best to transfer the recordings by CAREFULLY removing the SD card from the radio and inserting it into a card reader on the PC. Be VERY CAREFUL moving the card between the radio and the PC. Be sure to power the radio off first and after using the card in the PC (or via the cable), BE SURE to RELEASE the SD card from the PC before removing it.

High level steps...

1. Update the PRO-668 provided programming software and library data (version 514 was released yesterday).
2. Import the system into a configuration
3. Create/set the wildcard talkgroup to RECord
4. Create/set the wildcard radio ID to RECord
5. Let the radio gather recordings for a while
6. Retrieve the recordings from the SD card into the PC software

The software should list in the appropriate columns all of the talkgroups and radio IDs seen.
 

kk6yus

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Location
Central Valley, CA
Yes, that is the system being monitored.

I believe the date base is outdated, however, as I discovered an agreement between the State of California and Sprint Nextel that mentioned a conflict in the control channel frequency. I was digging around and cannot locate the link.

Importing the system from the RR data base with an updated PRO668 library results in silence and no control channel shown. The RR Database listed control channel also does not appear on their ULS Application.

I do receive the Control Channel when the frequencies are manually input into the scanner with the software. I used the frequencies from their ULS Application (ULS License - PubSafty/SpecEmer/PubSaftyNtlPlan,806-817/851-862MHz,Trunked License - WNLU616 - CALIFORNIA, STATE OF - Frequencies Summary) instead of the RR Database.

I will follow your wildcard steps and let the scanner collect.
 
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