1. 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.
2. The base station modulator/demodulator according to claim 1 , wherein the receive means identifies, from data received from the higher rank station through the leased line, data addressed to said base station based on a virtual path identifier in header data preset in the base station, and the first send means identifies, from data received from the higher rank station through the leased line, data addressed to said another base station based on a virtual path identifier in header data preset in the another base station.
3. The base station modulator/demodulator according to claim 2 , which further comprises: discard means for discarding, among the data received by the receive means from the higher rank station through the leased line, data having a virtual path identifier different from the preset value; and insertion means for inserting idol data in place of the data discarded by the discard means.
4. The base station modulator/demodulator according to claim 1 , wherein the base station has the same processing function as the another base station.
5. A send/receive method in a mobile communication system for performing send/receive of data between a higher rank station and a base station, said method comprising: terminating data received at the base station from the higher rank station through a leased line in a leased line frame format, the data addressed to the base station; sending data received at the base station from the higher rank station through the leased line to another base station when the data is addressed to the another base station; multiplexing data of the base station and the another base station and sending the multiplexed data to the higher rank station through the leased line in the leased line frame; and performing band control in such a manner that, in multiplexing data of a 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.
6. The method of claim 5 , further comprising: discarding, among the data received by the receive means from the higher rank station through the lease line, data having a virtual path identifier different from a preset value; and inserting an idol cell instead of the discarded data.
7. The method of claim 5 , wherein the base station has the same processing function as the another base station.
8. The method according to claim 5 , wherein the base station has the same processing function as the another base station.
9. A base station in a mobile communication system comprising: an interface section to receive data from a higher rank station in the mobile communication system, the data being received over a leased line; a master receive processor configured to receive the data from the higher rank station, determine whether the data from the higher rank station includes information destined for the base station, and terminate the data at the base station when the data from the higher rank station is determined to include information destined for the base station; and a slave receive processor configured to receive the data from the higher rank station, determine whether the data from the higher rank station includes information destined for another base station, and transmit, over the leased line, the data to the another base station when the data from the higher rank station is determined to include information destined for the another base station.
10. The base station of claim 9 , wherein the leased line is used as a physical media sublayer and the data is mapped to the leased line frame format.
11. The base station of claim 10 , wherein the determinations made by the master receive processor and the slave receive processor are performed based on a virtual path identifier in the data.
