A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. Each transceiver covers a certain site area. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture...http://www.google.de/patents/US5287354?utm_source=gb-gplus-sharePatent US5287354 - Data protocol and monitoring system for RF trunking multisite switch global serial channel
