Conversation Type

SELECTIONS:

DEFINITIONS:

Message

The system assigns a traffic channel for the duration of a single transmission by one subscriber. When the subscriber de-keys, all subscribers remain on the traffic channel until the traffic channel hang time expires. Once the hang time expires the subscriber radios return to the control channel. Any radio involved in the call may key up while it is on the traffic channel without returning to the control channel. Message trunking is available on 3600 baud control channel systems.

Message trunking is not compatible with ASTRO 25 Systems.

Transmission

The system assigns a traffic channel for the duration of a single transmission by one subscriber. When the subscriber de-keys, the traffic channel is deallocated and all subscribers involved in the call return to the control channel. Any subsequent traffic channel requests are sent in on the control channel by the requesting radio.

PTT ID

The system assigns a traffic channel for the duration of the entire conversation as follows. After a subscriber de-keys, the voice channel stays active (hang time) during which time the subscribers stay idle on the voice channel. Any subscriber responding during this hang time will first key up on the control channel to send a message with the unit's PTT-ID (Unit ID) indicating it wants to send audio now for this call; the system then sends a grant message directing the subscriber back to the same voice channel acting as the new source.