Trunking

“Sarah, get me the courthouse.”

The sharing of a small number of radio channels between a large number of users

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Voice Channels

Individual users can be combined intocollections called . They are made up of a collection of users who typically need to communicate in order to accomplish their job.

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Talkgroup

Talkgroup

Compare a trunkedcommunication system to the system many airlines use.
•Any agent can handle a transaction for any user. •Each user is handled by the next available ticket agent.

If there are more users than ticketagents, a single queue builds up. The single queue gives all users equal access to the available ticket agents.
•It is improbable that a large percentage of users will want to make a call at thesame time. •Most conversations are relatively short.

A Motorola trunked radio system also uses a that functions like a traffic officer and controls the operation of the trunked repeaters.

• Aseries of trunked repeaters • Operation and Assignment of the Control Channel - Who? - What? - Where?

Step 1: Central Controller Receives a Call Request

Step 2: The central controller assignsone of the idle repeaters to the user’s talkgroup. In this case, Repeater 5 is assigned.

Step 3: All radios monitoring the control channel receive the transmitted message.

Step 4: All of thoseradios assigned to the talkgroup associated with the Talkgroup ID switch to the assigned voice channel frequency.

Voice

Step 5: When the call is completed, the radios in the talkgroup switchback to the control channel frequency. The previously assigned voice channel now becomes available for other calls.

The Prime Site has lost communication to the central controller.
Radios operate asthey would in a normal trunking environment, except, if there are other entity sites in your system, the radio user will not be able to communicate with radios that have roamed outside their home...