Pre-Grant Publication Number: 20110135095
Filing Date: December 29, 2008Priority Date: June 16, 2008
Inventors: Xuwu Zhang, Lu Gan, Qing Huang
Assignee(s): ZTE CORPORATION
Current U.S. Classification: 380, 380/272000
View Prior Art for Claim 00020
The generating method according to Claim 2, wherein the specific steps are as follows when the UE transfers in an idle state from the EUTRAN to a GERAN:B1: after receiving a context request message or an identification request message, the MME generates an IK and a CK based on the KASME, and sends the KSIASME together with the IK and the CK which are generated from the KASME to the SGSN through a context response message or an identification response message;B2: after receiving the KSIASME, the IK and the CK from the MME, the SGSN generates a Kc of the GERAN based on the IK and the CK, maps the KSIASME into a CKSN of the GERAN, and stores the CKSN of the GERAN together with the Kc of the GERAN; and the SGSN sends the UE a message of indicating mapping completion of the CKSN of the GERAN; andB3: the UE maps the KSIASME into a CKSN of the GERAN, and stores the CKSN of the GERAN together with the Kc of the GERAN generated from the KASME. 
