SYSTEM AND METHOD FOR MOBILE COMMUNICATIONS IN COEXISTENCE WITH ESTABLISHED COMMUNICATIONS SYSTEMS

摘要

A mobile communications system (10) provides communications with mobile users (22) in the interference zones (32) of communications services having priority of use of the frequency band in which the mobile user operates. The frequency band has been previously allocated for use by other services, such as fixed microwave service (FMS) (26); however, by means of the invention, the mobile user is able to conduct communications on a subband or subbands in that frequency band. A position locating system (12) determines the position of the mobile user, and if the user (22) is within an interference zone (30), the mobile user is assigned subbands for operation in the previously allocated frequency band that is outside the subbands of the FMS (26). The system may have surface and/or satellite nodes and a network controller that monitors the mobile user's position and controls the nodes and user to subbands. Mobile users are isolated from the FMS sites either by continuous management of their frequency assignments, by calculations and commands sent from the network controller to the mobile user or by computations of the mobile user's unit.