Patent ID: 7200131

Claim:
A base station modulator/demodulator in a mobile communication system for sending data to a higher rank station and receiving data from the higher rank station, said base station modulator/demodulator comprising: receive means for receiving the data from the higher rank station through a leased line in a leased line frame format and for terminating the data from the higher rank station that is addressed to a base station; first send means for sending data received from the higher rank station through the leased line, when the data is addressed to another base station, to the another base station; and second send means for multiplexing data of a plurality of base stations and sending the multiplexed data to the higher rank station through the leased line in the leased line frame format, wherein the second send means performs band control in such a manner that, in multiplexing data of the plurality of base stations and sending the multiplexed data through the leased line to the higher rank station, the number of times of sending the data of the base station and the data of the another base station is varied based on a band set value predetermined for the leased line.