Path switching system, path switching method, and mobile terminal
A path switching system is provided, in which when UE has been offloaded from a first PDN-GW to a second PDN-GW, if there is an additional connection of the UE to the first PDN-GW, processing related to the additional connection can be performed on the UE side. The system includes: a control unit for sending a mobile terminal a message including information indicative of having switched relay devices, which relay a packet between the mobile terminal and a communication device, from a first relay device to a second relay device; and the mobile terminal for determining whether there is an added path other than part of a path from the mobile device before movement to the communication device and capable of being managed by the control unit, established between the mobile terminal and the first relay device, and when there is the added path, performing processing on the added path.
1. A mobile terminal used in a path switching system that switches a path used to exchange a packet in a communication session between the mobile terminal and a communication device as a communication partner of the mobile terminal through a network having a plurality of relay devices in connection with movement of the mobile terminal, the mobile terminal comprising:
a receiving unit configured to receive a message from a control unit that performs connection management of the mobile terminal or a gateway device to which the mobile terminal is connected, wherein when switching between the relay devices to relay the packet to be exchanged during a first communication session between the mobile terminal and the communication device along with the movement of the mobile terminal, the message includes information indicative of having switched from a first relay device before the movement of the mobile terminal to a second relay device after the movement of the mobile terminal;
a determining unit configured to determine, upon receiving the message, whether there is a second path other than a first path capable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device, where the second path is incapable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device; and
a processing unit configured to perform predetermined processing on the second path, when there is the second path, based on information on a second communication session between the mobile terminal and the communication device, where the second communication session is different from the first communication session,
a determination is made that a packet to be exchanged for the second communication session can be exchanged via a new path capable of being managed by the control unit, established between the mobile terminal and the second relay device, the processing unit performs processing for deleting the second path.
2. A mobile terminal used in a path switching system that switches a path used to exchange a packet in a communication session between the mobile terminal and a communication device as a communication partner of the mobile terminal through a network having a plurality of relay devices in connection with movement of the mobile terminal, the mobile terminal comprising:
a receiving unit configured to receive a message from a control unit that performs connection management of the mobile terminal or a gateway device to which the mobile terminal is connected, wherein when switching between the relay devices to relay the packet to be exchanged during a first communication session between the mobile terminal and the communication device along with the movement of the mobile terminal, the message includes information indicative of having switched from a first relay device before the movement of the mobile terminal to a second relay device after the movement of the mobile terminal;
a determining unit configured to determine, upon receiving the message, whether there is a second path other than a first path capable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device, where the second path is incapable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device; and
a processing unit configured to perform predetermined processing on the second path, when there is the second path, based on information on a second communication session between the mobile terminal and the communication device, where the second communication session is different from the first communication session,
a determination is made that a packet to be exchanged for the second communication session cannot be exchanged via a new path capable of being managed by the control unit, established between the mobile terminal and the second relay device, the processing unit performs processing for maintaining the second path.
3. A mobile terminal used in a path switching system that switches a path used to exchange a packet in a communication session between the mobile terminal and a communication device as a communication partner of the mobile terminal through a network having a plurality of relay devices in connection with movement of the mobile terminal, the mobile terminal comprising:
a receiving unit configured to receive a message from a control unit that performs connection management of the mobile terminal or a gateway device to which the mobile terminal is connected, wherein when switching between the relay devices to relay the packet to be exchanged during a first communication session between the mobile terminal and the communication device along with the movement of the mobile terminal, the message includes information indicative of having switched from a first relay device before the movement of the mobile terminal to a second relay device after the movement of the mobile terminal;
a determining unit configured to determine, upon receiving the message, whether there is a second path other than a first path capable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device, where the second path is incapable of being managed by the control unit, established between the mobile terminal before the movement and the first relay device; and
a processing unit configured to perform predetermined processing on the second path, when there is the second path, based on information on a second communication session between the mobile terminal and the communication device, where the second communication session is different from the communication session,
wherein
the message further includes information indicative of having deleted the second path, and
based on the information indicative of having deleted the second path, the processing unit performs processing, instead of the predetermined processing, that establishes a new path of a type identical to that of the second path between the first relay device and the mobile terminal, or that establishes a new path of a type identical to that of the second path between the second relay device and the mobile terminal.