Site trunking talkgroup

[sonm10]

Hello folks,
Just a quick question, what is TGID 7 Site trunking?
Can I assume this is used when a site may be isolated from the network? Only reason I ask, UniTrunker shows affiliations on the talkgroup - Kandiyohi County UID affiliation off the Freeport site. A little over a week ago, a Crow Wing County UID affiliates as well. I'm just trying to figure out why these radios may be using this Site trunking talkgroup. Thanks for any insights.

Edit: before anyone from out of state asks this is for Minnesota's ARMER.

 

[northwoodsradio]

Hello folks,
Just a quick question, what is TGID 7 Site trunking?
Can I assume this is used when a site may be isolated from the network? Only reason I ask, UniTrunker shows affiliations on the talkgroup - Kandiyohi County UID affiliation off the Freeport site. A little over a week ago, a Crow Wing County UID affiliates as well. I'm just trying to figure out why these radios may be using this Site trunking talkgroup. Thanks for any insights.

Edit: before anyone from out of state asks this is for Minnesota's ARMER.

Site trunking is a talkgroup that is used for a tower that looses connection to the systems central controller to the system and goes into “site trunking”. The takkgroups is a specific talkgroup that can be used to hail a PSAP if they are on a tower that is in site trunking. Some PSAPS have control stations that affiliate to a specific site to pick up radios that affiliate to the site trunking talkgroup. I am wondering if conditions might be drifting some of those control stations from their native site to another during ducting, etc.

But essentially it’s a designed talkgroup for if a tower is in site trunking to talk as a generic landing talkgroup. Hope that makes sense

 

[sonm10]

Thanks. I kinda figured. It seems strange to see a radio affiliating when clearly the site is fine.
Can you elaborate on the control stations - why am I seeing affiliations from UIDs clearly outside my county?

 

[northwoodsradio]

What is most likely happening is that control station is essentially a mobile radio that is tied to antenna at the county psap dispatch center and its normal suppose to affiliate to a site within the county but with the ducting conditions it’s drifting to other sites.

Every summer I radios on Unitrunker that like to drift to other sites when conditions are favorable

 

[mmtstc]

Thanks. I kinda figured. It seems strange to see a radio affiliating when clearly the site is fine.
Can you elaborate on the control stations - why am I seeing affiliations from UIDs clearly outside my county?

Radios users can manually affiliate to that talkgroup. I have It in my work radio.

When we go into site trunking, I may not be able access to one of my dispatch centers if i am roaming away from our primary sites or home zone, so the way i understand it, is that it acts similar to MSP-CALL or a regional calling talkgroup but on a hyper local scale, where i can use SITE TRUNK to have guaranteed access whatever local PSAP I happen to be in the area of. There are some counties that are not simulcast that have multiple unique sites and they may have a site trunking talkgroup for each RF site.

Site Trunking happens once or twice a year while they push updates to the system and typically lasts about 5 minutes. There are certainly unscheduled downtimes that also occur, but they are typically limited to a zone or a specific site. seems like it has gotten better overall since the system has largely transitioned to fiber optic linking versus microwave linking. Microwave is very prone to rain fade disrupting comms during weather whereas fiber's biggest vulnerability is every fly-by-night underground utility contractor that is pushing fiber optic lines through the ground. That being said, the microwave backhaul links still generally exist (going away by lifecycle attrition), so the radio techno wizards can MacGuyver their way to a solution with relative ease.

 

[Ubbe]

I don't know how that ARMER system are setup but on system I configure I make a TG7 to have the name of a site and that TG will only be valid on that site, and then do the same thing to all sites. That way a radio that selects TG7 will be rejected on all sites until it finds site 7. The units that operates within the site 7 coverage are instructed to use TG7 in case of site trunking so all local units can talk to each other and if a dispatch center has a good enough antenna, or maybe a RF link or fiber to a remote radio location, it can reach that site and have contact with each unit if needed, usually if someone push their emergency call button.

Sometimes a user goes thru all TG's on his radio to see what he has and if he lingers too long on one, to give time to read its text label, it will send an affiliation request to the site.

/Ubbe