Abstract: A repeater which enables portable radio terminals to operate outside the normal coverage area of a trunked radio network. The repeater combines two wireless transceivers which may simply be radio terminals coupled together in a vehicle, for example. One transceiver communicates control messages to and from the trunked network using a full or half duplex channel. The other transceiver communicates with the portable terminals using a half duplex or simplex channel. The link from the repeater to the network includes a generally continuous control channel while the link to the portable terminals is generally non continuous with intervals for messages from the terminals back to the repeater.

Abstract: A repeater system for hand portable radios that may be outside normal coverage in a mobile radio system. Short messages or emergency messages from the portable radio are transmitted to an on-board or other mobile station, and forwarded from there to a central station or other required station in the system. The on-board station generally has a higher powered transmitter than the portable station and is within network coverage when the messages are received. The on-board station might be carried by a vehicle for example, and the portable station might be carried by a public safety official who has left the vehicle to investigate a nearby event.