Beacon detection method and apparatus for sharing spectrum between wireless communications systems and fixed microwave systems

摘要

A system for spectrum sharing between a point-to-point microwave system and a TDM/TDMA wireless communications system in a common geographical area is described. Each transmitter/receiver in the point-to-point microwave system transmits, in addition to its normal information signal, a beacon signal which is uniquely associated with the receiver receive frequency. In selecting uplink and downlink frequencies for port assignment, each port monitors the beacon frequencies and selects as uplink and downlink frequencies, frequencies which associated beacons fall below a predetermined threshold. Similarly, before accessing the wireless communications system through a selected port, a portable monitors the beacons associated with the selected port's uplink frequency. If the beacon associated with the uplink frequency exceeds a threshold, the portable selects an alternate port through which to access the network. Also, during a call an emergency link transfer to another port is made if the monitored beacon corresponding to the portable's uplink frequency rises above the threshold.