Patent ID: 7813511

Claim:
A method for providing a mobility key for a communication session, comprising: facilitating initiation of the communication session for a mobile station; receiving a master key at an access router of a foreign network, the foreign network distinct from a wireless local area network, the master key received from a foreign authentication server located in the foreign network and operable to receive the master key from a home authentication server located in a home network of the mobile station, the home network operable to authenticate the mobile station at the home authentication server to verify the authenticity of the mobile station, generate a master key for the communication session in response to authenticating the mobile station, and send the master key to the foreign authentication server; deriving one or more mobility keys from the master key in response to the same authentication request, the mobility keys derived at the access router and independent of the mobile station, the mobility keys including a mobile station-network node key shared between the mobile station and a network node, the mobile station-network node key operable to authenticate mobility signaling to the network node of the communication network, the access router distinct from the foreign authentication server, each mobility key of the one or more mobility keys used by the access router to send messages on behalf of the mobile station and independently of the mobile station, the mobility keys operable to authenticate layer 3 mobility signaling for the communication session; deriving an access key from the master key, the access key operable to authenticate layer 2 messaging for the communication session; and sending a signal message to the network node, the signal message authenticated using the mobile station-network node key.