Allocation of a radio access bearer with a lower rate than desired in case of lack of resources, if an indicator in the assignment request indicates that the communication rate is negotiable

摘要

A WCDMA communication system that enables smooth data transmission although a communication rate corresponding to a communication service desired by a user can not be ensured due to lack of resources. If the desired communication rate can not be ensured due to lack of resources, instead of an alternative lower communication rate which is compulsorily set to by the base station control station (2-1, 2-2), the communication rate for actually effecting a data communication is negotiated between a switching center (1) and the base station control stations (2-1, 2-2), only when it is possible to provide a service at a communication rate lower than the requested communication rate.An indicator that indicates whether the communicationrate can be negotiated or not is provided in a RAB assignment request to be transmitted from the switching center (1) to the base station control stations (2-1, 2-2). Only when this indicator indicates passable, the base station control stations (2-2, 2-2) decide, in the case of lack of resources, a communication rate lower than the desired communication rate, and transmit to the switching center (1) a RAB assignment response containing this decided communication rate. The communication service for a user terminal (4) is started in accordance with this communication rate.