Patent ID: 8565761

Claim:
A mobile communication method comprising the steps of: (A) performing, at a mobile station having established a first connection in a first cell, a modification process to modify a configuration of the first connection, in response to a reconfiguration signal from a radio base station managing the first cell; (B) storing, at the mobile station, transaction identification information included in the reconfiguration signal, and transmitting, from the mobile station to the radio base station managing the first cell, a reconfiguration complete signal including the stored transaction identification information, when succeeding in the modification process; (C) performing, at the mobile station, a cell selection process when detecting failure in the first connection; (D) transmitting, from the mobile station to a radio base station managing a second cell selected by the cell selection process, a connection re-establishment request signal including the transaction identification information and a security parameter for specifying the first cell and the mobile station; (E) determining, at the radio base station managing the second cell, whether or not to have stored context information of the mobile station having transmitted the connection re-establishment request signal; (F) transmitting, from the radio base station managing the second cell to the radio base station managing the first cell, a context request signal including the transaction identification information and the security parameter, when the radio base station managing the second cell determines that it does not store the context information of the mobile station; (G) specifying, at the radio base station managing the first cell which has received the context request signal, the context information of the mobile station based on the transaction identification information and the security parameter, and transferring, from the radio base station managing the first cell to the radio base station managing the second cell, the specified context information of the mobile station; and (H) establishing, at the radio base station managing the second cell and the mobile station, a second connection in the second cell for the mobile station based on the context information of the mobile station.