Patent ID: 7230940

Claim:
A network controller for facilitating roaming of a mobile wireless communications device between access points, the network controller comprising: a network interface for communicating with at least one access point over a wired network, the at least one access point being configured for communication with a mobile wireless communications device over a wireless network; and a data processing system in communication with the network interface, the data processing system including a protocol stack for facilitating a communication session between the mobile device and a network device on the wired network, and a session table identifying session information for each said communication session, the session information identifying a current one of the access points with which the mobile device is currently associated, the protocol stack being configured to update the session table from the session information received from the current one access point, the protocol stack comprising: (i) a first protocol layer configured to maintain a first virtual circuit between the network controller and the network device; (ii) a second protocol layer configured to maintain a second virtual circuit between the network controller and the current one access point; and (iii) an intermediate protocol layer in communication with the first and second protocol layers and configured to bridge communication between the virtual circuits in accordance with the session information using the session table, the second protocol layer being configured to extract a transport layer data segment originating from the mobile device from a base station link layer datagram, the base station link layer datagram being received from the current one access point over the second virtual circuit and incorporating message data originating from the mobile device, the message data being encapsulated in the transport layer data segment, the transport layer data segment being encapsulated in a base station header identifying the message data as originating from the mobile device, the second protocol layer further configured to transmit the extracted transport layer data segment to the intermediate protocol layer.