Patent ID: 7010300

Claim:
A method of handing off a communication session with a mobile station when the mobile station is engaging in the communication session via a first access system and then registers in a second access system, wherein the first access system and second access system both provide access to a common transport network, wherein the first access system includes a first access node, wherein the second access system includes a second access node, wherein when the mobile station is in the first access system the mobile station communicates with a first access node according to a first protocol, and wherein when the mobile station is in the second access system the mobile station communicates with a second access node according to a second protocol different than the first protocol, the method comprising: after registration of the mobile station in the second access system, the mobile station encoding outgoing data of the communication session according to the first protocol so as to produce outgoing first-protocol-encoded data the mobile station encapsulating the outgoing first-protocol-encoded data in headers of the second protocol so as to produce outgoing second-protocol-encapsulated first-protocol-encoded data; the mobile station sending the outgoing second-protocol-encapsulated first-protocol-encoded data to the second access node; the mobile station receiving incoming second-protocol-encapsulated first-protocol-encoded data from the second access node; and the mobile station stripping headers of the second protocol from the incoming second-protocol-encapsulated first-protocol-encoded data so as to uncover incoming first-protocol-encoded data.