when you guys or ladies say talk groups (scanner)
- Thread starter N1XDS
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On a trunked system, every user is assigned a "Talk Group" to use instead of a channel like a conventional system uses.
TXFirefighter112
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The talkgroup can be reassigned randomly to different frequencies, everyone in with that talkgroup ID will hear it no matter what frequency they are on.
A good analogy (from the greek: "logos-to think/thinking" and english: "anal-relating to the ass" literally means to think through one's butt) is a room (control/data channel/frequency) with a bunch of other rooms connecting to eachother (frequencies) and a **** load of people (system radios). Since the "control room" has everyone, it cannot be used as a means of transmission. Now each radio has two ID's 1) the radio ID, and 2) the talkgroup ID. The talkgroup ID can be changed, the radio ID cannot. Anyway, lets say someone with the TG ID of 50 672 decides they need to talk to someone. They go to the site controller (key up the radio) and the site controller recieves the radio ID and the TG ID. using the TG ID, the site controller grabs everyone who has the same ID and selects a room for them to go talk in. All that happens at close to the speed of light.
When the original person is done talking, everyone leaves that frequency and returns to the data channel (unless someone keys up fast enough and keeps the frequency in use) then the next guy who talks on 50 672, will have to repeat the above process and they may be assigned to a different frequency.
Also with many systems, the control channel will change frequencies every 24 hours or so. The radio ID is really only important to the people who program the radios and dispatchers. It's main use comes in determining whether or not they are an authorized user of the system, but a very important use is the ability to tell who hit their emergency button.
I think that is a fairly accurate (if somewhat simple) way to look at how a trunked system works and how TG's and freq's are different. If I left anything out or got something wrong, Im sure someone will correct it...
A good analogy (from the greek: "logos-to think/thinking" and english: "anal-relating to the ass" literally means to think through one's butt) is a room (control/data channel/frequency) with a bunch of other rooms connecting to eachother (frequencies) and a **** load of people (system radios). Since the "control room" has everyone, it cannot be used as a means of transmission. Now each radio has two ID's 1) the radio ID, and 2) the talkgroup ID. The talkgroup ID can be changed, the radio ID cannot. Anyway, lets say someone with the TG ID of 50 672 decides they need to talk to someone. They go to the site controller (key up the radio) and the site controller recieves the radio ID and the TG ID. using the TG ID, the site controller grabs everyone who has the same ID and selects a room for them to go talk in. All that happens at close to the speed of light.
When the original person is done talking, everyone leaves that frequency and returns to the data channel (unless someone keys up fast enough and keeps the frequency in use) then the next guy who talks on 50 672, will have to repeat the above process and they may be assigned to a different frequency.
Also with many systems, the control channel will change frequencies every 24 hours or so. The radio ID is really only important to the people who program the radios and dispatchers. It's main use comes in determining whether or not they are an authorized user of the system, but a very important use is the ability to tell who hit their emergency button.
I think that is a fairly accurate (if somewhat simple) way to look at how a trunked system works and how TG's and freq's are different. If I left anything out or got something wrong, Im sure someone will correct it...
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