Mobile communication method and a switching station

A the handover before the communication to the communication after the handover, the information relating to security processing, appropriately take over. A mobile station UE, in the procedure for performing a handover to a cell subordinate to the radio base station eNB of the wireless base station NB cell from E-UTRA scheme under the UTRA scheme, the switching center of the E-UTRA scheme MME moth, E-UTRA system Roh radio base station eNB scolded, E-UTRA system Roh radio base station eNB door movement station UE door field between field communication de using is AS field security processing use algorithm wo including transparent container wo including the handover request response receives the message, with the switching center SGSN of the UTRA scheme, the step of transmitting a NAS PDU including the transparent container and the NAS security processing algorithm and the NAS security processing parameter of the. .FIELD 5