SERVICE CHANNEL REPLAY SYSTEM IN DIGITAL MICROWAVE COMMUNICATION SYSTEM

摘要

PURPOSE:To prevent relay of a service channel by reinserting a service channel from a reception system generating an alarm to a transmission system of the system in a relay station where a squelch alarm takes place. CONSTITUTION:A relay station consists of the 1st the 2nd lines, antennas 10a, 10b (suffixes a, b indicate the 1st and the 2nd system respectively), receivers 12a, 12b, transmitters 13a, 13b and tranmission antennas 11a, 11b. Service channel signals 14a, 14b are transmitted from the receivers 12a, 12b and the signals are switched by an SW100, branched (102) to an intra-office service channel 107 and further branched (103). The service channel 108 generated in the relay station is superimposed on the 1st and 2nd line by branching devices 104-106. Moreover, the service channel from a high-order station is controlled by switching SW101a, 101b. If a squelch alarm takes place, the SW100 is changed over and the service channel signal from the high-order is transmitted to the low-order. Thus, the continuity of the service channel is maintained.