A METHOD FOR ENCRYPTING SYNCHRONOUS COUNTER CHECKING IN A MOBILE COMMUNICATION SYSTEM

摘要

The present invention relates to a method of encrypting synchronization for communication data in a mobile communication system .It discloses a method of a counter checking for encrypting synchronization in the mobile communication system, enabling to avoid the unwanted RRC connection release generated due to the improper time at which the counter checking begins .The method of the counter checking for encrypting synchronization in the mobile communication system comprises the following steps: (A) determining the creditable range of connection frame number checking; (B) determining whether the sequence numbers of the protocol data unit in the radio link control layer are all between the said creditable range ,wherein the protocol data unit is in the up and down connection frame numbers ,if so ,starting connection frame number checking.