Announcment Groups?

[Caffiene]

What's the purpose for an Announcement talkgroup?
-Caff

[abbylind]

For us this is "all call" or a fleet call talkgroup
We have it on our Ericsson MaCom Tyco (you pick the name) system to announce major crimes in progress to all area commands
We call it "All Ops"
If its a fire department announcement talkgroup its probably used for overtime available for the firefighters to work or other admin messages.

Fowler

[Caffiene]

So for this to be effective, the radio would have to be in scan and this annoucement group would have to be in the scan list, right?
-Caff

[abbylind]

Yes you would need to enter that talkgroup in your scan
It may be like LAPDs hotshot channel. In progress calls felonies ect.

Fowler

[xmo]

You don't have it in your scan list. It will work even if the radios are set up without scan ability at all.

The thing that makes the announcement talkgroup magic is that the system gathers up all the correct radios regardless of what other talkgroup they are set to or whether or not they are scanning.

It has to be predefined and correctly set up both in the subscriber units and in the fixed end.

[wavetar]

In a trunking environment, the radio simply sits on the control chanel listening to the data. If it's programmed to respond to announcement group 800xxx, then anytime the system sends out that annoucement group, the radio will treat it just like an regular talkgroup call, switching to the assigned voice channel & unmuting it's speaker. No scanning involved. To get similar functionality in a conventional system, yes, you would need to have all the radios scanning a common channel.

Todd

[Twisted_Pear]

It's more dependent on the radio being properly programmed. Not much really goes on on the FNE side other than defining the group as ATG capable and saying so and so TGs are associated with it (SZ at least). When an ATG call goes out it's simply the TG with the t-bit set for ATG. The radio would receive it, notice the t-bit, and then compare it to the current personality's ATG. It's up to the radio which TGs get associated with that ATG.

Another nice perk, if I can describe it right, is you can use it to receive all the TGs in the personality the ATG is programmed in for. Once you park the radio on the ATG for the specific personality, all TGs are received for that personality. The only drawback is you don't know which talkgroup is active. Use it with scan and you increase what you can hear. I usually use it along with Trunker when figuring out unknown ASTRO TGs.

[Caffiene]

So, to verify, Announcement Talkgroups are "one way", from dispatcher to group members, right?

[wavetar]

Not necessarily. The field units can also be programmed with the announcement talkgroup in their regular talkgroup list. Although, generally, they aren't, because most times you only want dispatchers or supervisors to have announcement capability.

Todd

[ExKa|iBuR]

Okie, sorry to-rehash an old thread, but I was curious about an announcement tg...

Does the Announcement Talkgroup need to be programmed to a specific channel, just the same as a regular talkgroup, or does the radio switch to it automatically?

In other words, which of the following two scenarios are actually what happens:

1) Subscriber radio is sitting on regular ops talkgroup 123 and is told by his dispatcher to switch to the Announcement Talkgroup to get a broadcast.

-or-

2) Subscriber radio is stitting on regular ops talkgroup 123 and when a citywide broadcast is transmitted on an announcement TG, as long as the regular ops TG isn't busy, his radio will revert over the ATG.


The reason I ask, other than curiosity...where I live, one of the Type II systems here has a talkgroup which is used for the Emergency Task Force, which, aside from the highway channel, is all I really listen to. If I were to program the ETF talkgroup as if it were an announcement talkgroup, would my radio ALWAYS switch to that TG whenever there's activity, regardless if it was scanning or not? The way it is now, I have that talkgroup set up as a priority in a scanlist, but 99% of the time, my radio isn't scanning.

Thanks for your help!

-M

[wavetar]

Scenario #2 is the correct one, but what you're thinking of doing won't work. A true 'announcement' talkgroup is sent with the t-bit set for ATG. Without this bit, it's just another regular talkgroup as far as the radio is concerned. In fact, programming it as an announcement group in your radio will cause you to not hear it at all, since it'll never 'see' it as an announcement.

Todd

[ExKa|iBuR]

Oh okay, so the system just sends something out saying "Hey, listen up", and whatever you have programmed in as the ATG is what it listens on.

Got'cha.

Thanks for clearing it up

-Mike

[wavetar]

Exactly. Glad I could help.

Todd