Communication system

A mobility management entity (MME) for a communications network comprising a core network and a plurality of base stations, said mobility management entity comprising:

• a memory, adapted to store closed subscriber group (CSG) information;
• wherein the controller is configured to:
• receive a path switch request from a target base station, wherein the path switch request received from the target base station includes a tracking area identity (TAI), an EUTRAN cell global identifier (ECGI), a list of Evolved Packet System (EPS) to be switched, and a CSG access mode of the target base station;
• determine CSG membership based on a CSG ID and the CSG access mode received in the path switch request from the target base station;
• and
• update the stored CSG information in the event that a mobile device is handed over from a source base station to the target base station, wherein the stored CSG information is updated based on the CSG access mode of the target base station,
• wherein the list of EPS bearers to be switched comprises, for each EPS bearer, a respective transport layer address and a respective tunnel end point identifier.

A method of operating a base station for communicating with a mobile station, the method comprising:

• generating, when the base station is operating as a target base station, a path switch request that includes a tracking area identity (TAI), an E-UTRAN cell global identifier (ECGI), a list of Evolved Packet System (EPS) to be switched, and a closed subscriber group (CSG) access mode of the base station when operating as the target base station;
• and
• transmitting, when the mobile station is engaged in a handover to the base station when operating as a target base station, the path switch request that includes the TAI, the ECGI, the list of EPS bearers to be switched, and the CSG access mode, to a Mobility Management Entity (MME);
• wherein the path switch request includes the TAI, the ECGI, the list of EPS bearers to be switched, and the CSG access mode of the base station operating as a target base station, and
• wherein the list of EPS bearers to be switched comprises, for each EPS bearer, a respective transport layer address and a respective tunnel end point identifier.

A method of operating a mobility management entity (MME) for a communications network comprising a core network and a plurality of base stations, the method comprising:

• receiving a path switch request from a target base station, wherein the path switch request received from the target base station includes a tracking area identity (TAI), an EUTRAN cell global identifier (ECGI), a list of EPS bearers to be switched, and a closed subscriber group (CSG) access mode of the target base station;
• determining CSG membership based on a CSG ID and the CSG access mode received in the path switch request from the target base station;
• updating stored CSG information in the event that a mobile device is handed over from a source base station to the target base station, wherein the stored CSG information is updated based on the CSG access mode of the target base station,
• wherein the list of EPS bearers to be switched comprises, for each EPS bearer, a respective transport layer address and a respective tunnel end point identifier.