Communication system, communication method, mobile terminal, and base station device

A mobile terminal, comprising:

• a communication processing unit that performs protocol processing including a connection and a handover to a base station device;
• a connection establishment processing unit that switches between a connection to an external network PDN through the base station device and a connection using LIPA through the base station device;
• and
• an N3G connection establishment processing unit that performs a handover using a Non3G access method, wherein
• the connection establishment processing unit performs the handover using the Non3G access method through the N3G connection establishment processing unit when it is determined that an access point name (APN) of a connection destination notified from the base station device through the communication processing unit at a time of reconnection is an access point name (APN-L) for LIPA which is different from an access point name (APN-M) of the external network PDN which is an access point name (APN) of a connection destination specified through the communication processing unit at a time of initial connection.

A base station device, comprising:

• an LGW communication unit that performs a protocol for connection to a local gateway (LGW);
• a cellular communication unit for connection to a mobile terminal through a cellular channel;
• and
• a connection control unit, wherein
• the LGW communication unit stores an access point name (APN-L) for LIPA in a handover indication message to transmit the handover indication message to a mobility management entity (MME), and receives a context setup request message that stores the access point name (APN-L) for LIPA, as an access point name (APN) having a radio bearer established, from the mobility management entity (MME), and
• the connection control unit performs a setting process of a LIPA bearer which is different from a bearer to an external network PDN established before a handover through the cellular communication unit based on the access point name (APN-L) for LIPA stored in the context setup request message.

A communication system in which a mobile terminal returns from an idle mode to start communication, wherein

• a base station device stores an access point name (APN-L) of LIPA to which the mobile terminal is capable of being connected through the base station device, in a service request message for causing the mobile terminal to return from the idle mode and start the communication, and transmits the service request message to a mobility management entity (MME), and
• the mobility management entity (MME)
• selects an address of a local gateway (LGW) corresponding to the access point name (APN-L) of LIPA which is stored in the service request message, and
• transmits a context setup request message in which “APN-L” which is an access point name (APN), having a radio bearer established, is stored, to the base station device.

A communication system in which a mobile terminal performs a handover from a base station device to a macro base station eNB, wherein

• the macro base station eNB stores information indicating whether or not to allow LIPA to be performed on an access point name (APN) to which the mobile terminal is connected, in a handover indication message, based on a handover confirmation message received from the mobile terminal, and transmits the handover indication message to a mobility management entity (MME), and
• the mobility management entity (MME)
• hands over an established LIPA bearer to the macro base station eNB, when it is determined that LIPA is able to be performed based on the information indicating whether or not to allow LIPA to be performed, and
• extracts an address of a packet gateway PGW to which a connection on a LIPA bearer is connected based on subscriber information of the mobile terminal, when it is determined that LIPA is not able to be performed based on the information indicating whether or not to allow LIPA to be performed.

A communication system including a macro base station (eNB) and a mobility management entity (MME), in which a mobile terminal returns from an idle mode to start communication, wherein

• the macro base station eNB stores information indicating whether or not to allow LIPA to be performed on an access point name (APN) to which the mobile terminal is connected, in a service request message for causing the mobile terminal to return from the idle mode to start the communication, and transmits the service request message to the mobility management entity (MME), and
• the mobility management entity (MME)
• establishes an established LIPA bearer in the macro base station eNB, when it is determined that LIPA is able to be performed based on the information indicating whether or not to allow LIPA to be performed, and
• extracts an address of a packet gateway PGW to which a connection on a LIPA bearer is connected based on subscriber information of the mobile terminal, when it is determined that LIPA is not able to be performed based on the information indicating whether or not to allow LIPA to be performed.