Abstract: In accordance with the principles of the present invention, a method and apparatus for filtered wireless communications is provided. The method provides a filtered wireless zone, preferably for second-generation cellular systems. Signal levels from surrounding cells are tested. The identities and frequencies of surrounding cells are received and a list of the available frequencies of the surrounding cells is established. An available frequency that is geographically distant from the handset is chosen. This available frequency has a low signal strength relative to the other available frequencies. The chosen frequency is established as a private frequency. The private frequency is transmitted at a geographical distance close to and thus at a high signal strength relative to the other available frequencies. Thus, the handset switches to the private frequency. In one embodiment, the frequencies of the cells are Global System for Mobile Communications (GSM) frequencies.

Abstract: Within a wireless CDMA communication system (100), at least one dedicated inbound code (232, 332, 414-416) and at least one dedicated outbound code (234, 334, 418-420) are provided solely for use in providing group calls. Based on a dedicated inbound code, a subscriber unit transmits a group call signal (505) and a base transceiver system receives the group call signal (703). In turn, the base transceiver system retransmits the group call signal based on a dedicated outbound code (709). Alternatively, or in addition, the base transceiver system sends the group call signal, along with information regarding the dedicated inbound code, to a controller (705-706). Subscriber units can receive group code updates (502, 602) indicating the particular dedicated inbound and outbound codes to be used within a given site. In this manner, the communication system can provide group call functionality in a public system.

Abstract: Processing of dispatch calls in a multi-site communication system begins when a source communication unit initiates a request for a dispatch call. The request is routed to a controller which assigns a controlled device to support the request. In addition, the controller identifies the destination communication units, which site each of the destination units are in, and what controlled devices are needed to support the dispatch call. Having identified the controlled devices, the controller assigns all of the controlled devices needed the same temporary network address. With all the controlled devices having the same temporary network address, the controlled device assigned to support the request can transmit the messages generated by the source communication unit to other controlled devices using the temporary network address. Thus only one representation of a message produced by the source communication unit is transmitted from the assigned controlled device.

Abstract: 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.

Abstract: A dispatch communication system wherein a communication unit may move from the service coverage area of a first system to the service coverage area of a second system during a communication transaction without the need to re-initiate the call. Communication units and base sites under this invention are constructed to relay signals to and from the system where the call originated.