In telecommunications, trunking is a technology for providing network access to multiple clients simultaneously by sharing a set of circuits, carriers, channels, or frequencies, instead of providing individual circuits or channels for each client. This is reminiscent to the structure of a tree with one trunk and many branches. Trunking in telecommunication originated in telegraphy, and later in telephone systems where a trunk line is a communications channel between telephone exchanges. Other applications include the trunked radio systems commonly used by police agencies.