Telecommunications system and method

A mobile node arranged to provide a communications service to a user using an internet protocol, after the mobile node has roamed from a first home access network to a second visited access network and attached to a wireless access gateway, the mobile node being arranged

• to communicate a binding update message to a visited serving gateway node of the second visited access network via the wireless access gateway using the internet protocol, the binding update message including a unique identifier of the mobile node, and a request for an internet protocol address for the mobile node as if the mobile node were attached to the first home access network, and
• to receive a home internet protocol address from the visited serving gateway node of the second visited access network, in response to the binding update message, the visited serving gateway node having identified from the unique identifier of the mobile node that the first home access network is the home network of the mobile node and communicated the binding update message to the home gateway node, the home gateway node having allocated the home internet protocol address to the mobile node.

A serving gateway node forming part of a mobile access network, the serving gateway node being operable to provide a mobile node with an internet protocol address as if the mobile node were attached to a home access network of the mobile node, in response to a binding update message, the binding update message including a unique identifier of the mobile node, and a request for a home internet protocol address, the serving gateway node being operable

• in response to the binding update message, communicated to the serving gateway node of the mobile access network via a wireless access gateway using an Internet protocol, to which a mobile node has attached, to identify from the unique identifier of the mobile node the home network of the mobile node,
• to communicate the request for the internet protocol address to a home gateway node of a home access network of the mobile node, the home gateway node being responsive to the request to allocate a home internet protocol address to the mobile node, and
• to communicate the home internet protocol address received from the home access network to the mobile node.

A computer readable carrier including computer program instructions that cause a computer to implement a method of providing a mobile node with an internet protocol address as if the mobile node were attached to a home access network of the mobile node, in response to a binding update message, the binding update message including a unique identifier of the mobile node, and a request for a home internet protocol address, said readable carrier comprising

• instructions to communicate, in response to the binding update message, the serving gateway node of the mobile access network via a wireless access gateway using an internet protocol, to which a mobile node has attached, to identify from the unique identifier of the mobile node the home network of the mobile node,
• instructions to communicate the request for the internet protocol address to a home gateway node of a home access network of the mobile node, the home gateway node being responsive to the request to allocate a home internet protocol address to the mobile node, and
• instructions to communicate the home internet protocol address received from the home access network to the mobile node.

A computer readable carrier including computer program instructions that cause a mobile node to implement a method of providing a communications service to a user using an internet protocol, after the mobile node has roamed from a first home access network to a second visited access network and attached to a wireless access gateway, said readable carrier comprising:

• instructions to communicate a binding update message to a visited serving gateway node of the second visited access network via the wireless access gateway using the internet protocol, the binding update message including a unique identifier of the mobile node, and a request for an internet protocol address for the mobile node as if the mobile node were attached to the first home access network, and
• instructions to receive a home internet protocol address from the visited serving gateway node of the second visited access network, in response to the binding update message, the visited serving gateway node having identified from the unique identifier of the mobile node that the first home access network is the home network of the mobile node and communicated the binding update message to the home gateway node, the home gateway node having allocated the home internet protocol address to the mobile node.