| 摘要 |
The application relates to the procedures Routing Area Update RAU in UTRAN and Tracking Area Update TAU in LTE. Furthermore, it relates to PDP context procedure in UTRAN as well as PDN connection procedure in LTE. In the current RAU procedure, a SGSN, which fails to update the Routing Area, e.g. because it receives the DNS return error, sends a RAU Reject with the cause code CC#17 indicating a network failure back to the user equipment (114b). The cause code CC#17 in the RAU Reject causes the user equipment to send a new RAU Request. Thus, the user equipment is stuck in a loop of sending a RAU Request and receiving a RAU Reject. This problem is solved by the present application in that SGSN keeps track of the number of rejections when doing RAU. When the number of rejections is above a certain threshold, the SGSN will send a RAU Reject with cause code CC#10 to the user equipment (115b), whereby the cause code CC#10 indicates implicit detach of the user equipment. In other words, the cause code is changed from CC#17 to CC#10 and in order to avoid further looping. The same principle is applied to TAU in LTE as well as to PDP procedures in UTRAN and LTE. |
