METHOD FOR RAB REESTABLISHMENT IN MOBILE COMMUNICATION SYSTEM

摘要

PURPOSE: A method for re-setting an RAB(Radio Access Bearer) in a mobile communication system is provided to select an optimum QoS value and reduce a time loss by searching a service-available QoS value from a previously stored table in occurrence of failure of an RAB setting, and attempting an RAB setting by a newly set QoS value to check only bits corresponding to a cause of the failure. CONSTITUTION: An SGSN(Service GPRS Support Node) analyzes an RAB allocation response message that a base station has sent and recognizes an RAB setting to the base station has been failed(400). The SGSN counts the number of RAB settings as attempted(402). If the counted value is not larger than a pre-set number of RAB setting attempts, the SGSN analyzes a reason of the failure of the RAB setting(406). If the reason of the failure of the RAB setting is related to a fact that a guaranteed bit rate requested for downlink is invalid(D), a fact that a guaranteed bit rate requested for uplink is invalid(C), a maximum bit rate requested for downlink is invalid(B) and a fact that a maximum bit rate requested for uplink is invalid(D), the SGSN checks bits related to the reason of the failure(408). The SGSN checks a corresponding bit of a QoS parameter related to the failure of the RAB setting(410). If a value of the corresponding bit is 0, the SGSN changes the corresponding bit value of the QoS parameter to 1(414). The SGSN re-attempts an RAB setting with the newly set QoS values(416). If the RAB setting is successful, the SGSN allows an active PWL connection(420).