Home agent discovery upon changing the mobility management scheme

A mobile node capable of being re-directed to a first home agent, which was selected when the mobile node initially attached to an access system supporting network-based mobility, the mobile node comprising:

• a transmitter which, in operation, transmits to a second home agent an Internet Key Exchange (IKEv2) request message to establish a security association with the second home agent when the mobile node, which is attached to the access system supporting network-based mobility and for which the first home agent was selected, switches to attach to an access system supporting client-based mobility, the IKEv2 request message including an identifier of the mobile node;
• and
• a receiver which, in operation, receives from the second home agent an IKEv2 response message including redirect information containing one of an IP address of the first home agent and hints, the hints including at least one of an address prefix and a domain name and allowing the mobile node to derive a valid address for the first home agent, the valid address including one of an anycast group address, a multicast group address, and a unicast address;
• wherein the transmitter, upon receipt of the IKEv2 response message when the mobile node is attached to the access system supporting client-based mobility, initiates establishment of a new security association with the first home agent, to which the mobile node is re-directed and transmits a Mobile IP (MIPv6) Binding Update for registering a new care-of address (CoA) with the first home agent;
• and
• the receiver receives a MIPv6 Binding Acknowledgement from the first home agent that has received the MIPv6 Binding Update.

A second home agent capable of re-directing a mobile node to a first home agent, which was selected when the mobile node initially attached to an access system supporting network-based mobility, the second home agent comprising:

• a receiver which, in operation, receives from the mobile node an Internet Key Exchange (IKEv2) request message to establish a security association with the second home agent when the mobile node, which is attached to the success system supporting network-based mobility and for which the first home agent was selected, switches to attach to an access system supporting client-based mobility, the IKEv2 request message including an identifier of the mobile node;
• and
• a transmitter which, in operation, transmits to the mobile node, which is attached to the access system supporting client-based mobility, an IKEv2 response message, the IKEv2 response message including redirect information containing one of an IP address of the first home agent and hints, the hints including at least one of an address prefix and a domain name and allowing the mobile node to derive a valid address for the first home agent, the valid address including one of an anycast group address, a multicast group address, and a unicast address,
• wherein the mobile node is re-directed to the first home agent, with which the mobile node initiates a new security association and transmits a Mobile IP (MIPv6) Binding Update for registering a new care-of address (CoA) therewith and receives a MIPv6 Binding Acknowledgement therefrom.