METHOD OF ESTABLISHING COMMUNICATION BETWEEN INDEPENDENT COMMUNICATION SYSTEMS

摘要

In one embodiment, independent communication systems (101 and 102) are provided with additional receivers (112 and 113) that allow the systems to monitor one anothers' outbound control signalling channels. Secondary control signalling (204) can be interleaved with the primary control signalling (201) information on this communication resource, which secondary control signalling information is intended for reception and use by the monitoring system. In another embodiment, communication systems (301 and 302) having dedicated communication resources are provided with receivers (311 and 316) that monitor the communication resources of other communication systems. Communications between communication units (321 and 323) in various systems are interchanged through appropriate interaction of the repeaters and the dedicated receivers so provided. In another embodiment, communication systems (401 and 402) having dedicated communication resources are provided with receivers (416) that monitor the communication resources of other communication systems, and roamers (423) are preregistered (431) in non-home systems. Using this infrastructure, a group call can be sourced in one system and relayed to roamers located in other systems.