Mobile communication system, radio base station controller, and relocation method

Abstract

Radio base stations connect by radio lines with radio terminals in cells that make up each radio base station and relay data communication realized by the radio terminals on bearers on radio lines. Base station controllers record correspondence information of the data flow of data communication with the radio terminals and the bearers on the radio lines and, by referring to the correspondence information, effects termination of data communication with the radio terminals. When, in a state in which a drift base station controller relays and transfers data communication between radio base stations to which the radio terminals are connected and a serving base station controller, the serving base station controller is transferred to the drift base station controller, the plurality of base station controllers then report to the drift base station controller the correspondence information from the serving base station controller.

1 . A first communication device comprising:
 a transmitter that transmits a Signaling Radio Bearer (SRB) ID and an ID concerning with data flow to a second communication device,   wherein the first communication device communicates with a terminal until the terminal performs handover to the second communication device,   wherein the SRB ID is mapped with the ID concerning with data flow, and   wherein SRBs are radio bearers that are available for transmission of Radio Resource Control (RRC) messages.   
     
     
         2 . The first communication device according to  claim 1 ,
 wherein the first communication device controls a first base station device, and   wherein the second communication device controls the first base station device.   
     
     
         3 . A radio terminal comprising:
 a receiver that receives a control signal from a first base station device, and a controller that performs handover from a first communication device to a second communication device,   wherein the first communication device transmits a Signaling Radio Bearer (SRB) ID and an ID concerning with data flow to the second communication device,   wherein the first communication device controls the first base station device,   wherein the second communication device controls a first base station device,   wherein the SRB ID is mapped with the ID concerning with data flow, and   wherein SRBs are radio bearers that are available for transmission of Radio Resource Control (RRC) messages.