WESTMORELAND COUNTY
800 Mhz
Explanation of Trunking
part of K3SAM.COM
WHAT IS TRUNKING
Trunking is not that hard to understand. Let us compare frequencies to toll booths. Let us say that you are on the Pennsylvania Turnpike going to Ohio. In this case the Turnpike would be your radio. In order to get to Ohio you have to go through the last set of toll booths. Again, in this case the tolls booths would be compared to a group of frequencies. On the other side of the Pennsylvania Turnpike is another road, the Ohio Turnpike. In this case the Ohio Turnpike would be the dispatching radio, or just another radio you wish to connect to.
So, for your radio ( PA Turnpike ) to connect to the other radio ( Ohio Turnpike ) you have to find an open frequency ( Toll Booth ) to use to make contact ( connect together ). As different radios on the Turnpikes ( roads ) need to connect then different frequencies ( booths ) will have to be used. The booth that is open would be the frequency that is associated with this example. The next car on the PA Turnpike ( radio ) behind you would have to use another booth ( frequency ) to connect to the Ohio Turnpike ( dispatch or another car radio ) as the toll booth ( frequency ) you are using is busy.
Same with trunking. As one frequency becomes open it is used. That frequency is then busy. So the next request for a frequency will bypass that one and find an open one. A dispatcher may call Car 4 and the radio will select channel 1. By the time the dispatcher is done talking to Car 4 the radios may have switched frequencies 5 times. All this is done without either party knowing it. Very smart radios. This is called Trunking.