I will throw my $1.95 in. . . . and there are those that will question what I say and argue with it. . . . Several admins for the PA discussion forums can vouch for my background. . . .
The ASTRO25 controller at Westmoreland was upgraded a few years ago with DHS funds to support adding new sites (aka counties) onto the system.* The version controller they were running was an older setup that didn't support the newer format infrastructure equipment. . . . to put new sites on required upgrading the controller to a full IP based system . . .
Indiana and Armstrong counties are in process of “joining” or connecting to this controller (aka switch) for trunking in their respective counties. . . .
This means until all the programming in the controller and sometimes field units that talkgroups from one county may be carried on a tower in another county.* Permissions may still allow that to happen, but as the towers are turned on, until optimization and all the backend programming refined, it is very possible for a Westmoreland District 5 talkgroup to pop up on an RF site in Armstrong since they are all ultimately talking back to the same trunking controller in a “WIDE AREA COMMUNICATIONS NETWORK”
Fayette should be the next one joining. . . . . .
Folks may wish to update their thinking from saying “Westmoreland trunking system” “Armstrong trunking system” to a more regional thinking where resources (aka talkgroups) are carried by the tower sites connected to the regional system.
As such, any entity on the system if their talkgroup is allowed to roam could be showing up on any radio tower in range. . . (Lots of variables in the trunking controllers and even in the radios thta affect how/when the roam can occur, although ability of a talkgroup to roam at all is strictly in the trunking controllers)
Those of us with high profile towers are the ones who have the major issue with roaming. . . . The fact that my one tower in Fayette covers, Fayette, Westmoreland, Washington, and Allegheny is definately an issue. . . . .
So far everything is APCO25 Phase 1 Trunking operating on 800 MHz. . . . .
As always this has been my $1.95, YMMV, no warranty implied, yadda yadda yadda.
Have a great day!
Tony