VARIABLE BAND COMMUNICATION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To enable a band change which is fast and flexible by grasping the free band of a connection by a subscriber exchange in advance when there is no band change request. SOLUTION: The subscriber exchange 11 is equipped with a free band table 101 which stores information regarding the use state of a transmission line. When a terminal device 31 generates a band change request to a network, the subscriber exchange 11 including the terminal equipment 31 receives it and judges the propriety of the request. Namely, the subscriber exchange 11 compares the requested band with the contents of the free band table 101 at the request and does not comply with the request when a free band is exceeded. When request acknowledgement is sent back to the terminal equipment 31 from the exchange 11, the terminal equipment 31 starts transferring a cell immediately. Further, a requested RM cell from the terminal device 31 is transferred to the exchange of the next stage as it is and respective repeating exchanges secure the band.