Method for a communication unit to operate in either a trunking or a cellular communication system

摘要

A communication unit may operate in either a trunking communication system and a cellular communication system when the coverage areas of each system overlap. Typically, the communication unit is affiliated with the trunking communication system and operates normally therein. When a call is received or being placed via the cellular communication system, the communication unit transfers its affiliation to the cellular communication system and operates therein. The communication unit is prompted by the trunking communication system to transfer its affiliation for incoming calls and does so automatically for outgoing calls. Once the communication ends, the communication unit transfers its affiliation back to the trunking communication system within a predetermined period of time.