What is Two-Way Radio Trunking?

There are a number of ways to operate a two-way radio, and although these devices may seem simple, some of their more advanced uses are fairly complex. One of these unique usages is something called "trunking," which is a way to share a small number of two-way radio frequencies with a large group of users.

With trunking, this group of people (whether it be a group of coworkers, friends, family, or a social organization), can take advantage of one "talkgroup," instead of one singular channel. This means that individual users are able to talk to other users in the group at any time, rather than waiting for idle time in the conversation to pass until someone else is able to chat. The talkgroup automatically finds a vacant channel within the group whenever the person decides to call in, enabling unrelated conversations to occur at once within the channel.

A trunked radio system works because each individual user's radio will send data packets to a computer, which operates on what is called a "control channel". This channel requests communication within the talkgroup by sending a digital signal to all other radios within the group, and it then instructs those radios to switch to the frequency indicated. Once the initial user is done speaking, all of the other radios will return to monitoring the control channel in case of other transmissions.   

Many people don't understand the difference between the way a trunked radio system works and the way that a conventional system works. Basically, a standard radio system uses one designated channel or frequency for a group of users, while a trunked system uses a number of different channels for one group of people. This means that when talk is idle on one channel, the same people will hear communication on the other channels.