Patent ID: 8229120
Filing Date: 2012-07-24
Classification: H04L,H04W

Abstract:
1. A mobile communication method for communicating between a mobile station and a radio base station via a radio link by using a certain key, the method comprising the steps of: (A) transmitting, from the mobile station to the radio base station, a re-establishment request signal, detecting radio link failure; and (B) performing a reconfiguration of the radio link between the mobile station and the radio base station in response to the transmission of the re-establishment request signal; wherein in the step (B), the radio base station transmits, to the mobile station, a re-establishment acknowledge signal including an index parameter for identifying a second key for calculating a first key for generating the certain key to be used in the radio base station after a re-establishment procedure, and the mobile station calculates the first key to be stored in the mobile station by using the second key identified by the index parameter included in the received re-establishment acknowledge signal.