Trunked at capacity

[chrismol1]

A curious what if scenario question regarding capacity, system a ASTRO25 trunked with 2 zones

Zone 1 has more channel capacity than zone 2. Both zones have a talkgroup affiliated say a law enforcement TG1 so its typically always affiliated both zones on the system. Say a bunch a of DPW trucks only on zone 2 start using the channels and zone 2 is near capacity and sometimes putting out busy's in queue

What happens if on zone 2, a user from zone 1 makes a group call on the leo TG1 but all the channels in zone 2 are in use by DPW? Could it cut off a DPW TG to make a channel available for the law enforcement radio to receive their TG? What happens in a scenario like this?

 

[MTS2000des]

What happens if on zone 2, a user from zone 1 makes a group call on the leo TG1 but all the channels in zone 2 are in use by DPW? Could it cut off a DPW TG to make a channel available for the law enforcement radio to receive their TG? What happens in a scenario like this?

Depends on how the talkgroups are provisioned. Fast start vs. all start plays a big factor. If fast start is set, then the requestor at the site will get a resource on the site with available talk path, and the "full" site will not carry the talkgroup until the resource becomes available. All start requires all available sites to have resources available before the call will be setup.

A talkgroup can have a higher priority, but if I recall, a conversation is in progress, in FDMA, the conversation will have to end before that resource can be made available to the higher priority talkgroup, and then the fast start vs. all start selection also comes into play. TDMA can allow for interruption.