ITU-R - International Telecommunication Union/ITU Radiocommunication Sector
Scope
"Introduction Radio spectrum allocated for dispatch traffic is becoming increasingly congested and already many users (networks) have to share a channel with several other users. This practice employs the channel more effectively but gives the participants a reduced ""grade of service"" in the sense that they may often have to wait for some time for a channel to become free and they suffer from reduced privacy. Not only improved channel utilization but also better grade of service and good privacy conditions are important factors to design dispatch systems. Part A of this Report deals with the general aspects of multi-channel land mobile systems for dispatch traffic@ such as system configuration@ characteristics of dispatch traffic@ grade of service@ traffic handling capability@ performance of trunked systems@ signalling and so on. Part B of this Report introduces some systems being installed or planned by some administrations. For this purpose of this Report@ ""dispatch system"" has the meaning: A radio system used to control the operation of a fleet of mobiles@ such as air craft@ taxis@ police@ etc.@ and ""trunked system"" has the meaning: A multi-channel system with automatic channel selection@ particularly referring to dispatch systems. However@ this Report does not consider the detail of interconnection of trunked dispatch systems with public or private switched telephone networks. Such interconnection requires further study."