Patent ID: 7032009

Claim:
For use in a system comprising a mobile unit, a cellular network, a wireless local area network coupled to an Internet, and a remote server system, wherein the remote server system receives an indication that the mobile unit has roamed into a coverage area of the wireless local area network via a packet switched data network at a transport layer or above from at least one of the mobile unit, the cellular network, and the wireless local area network, the remote server system is configured to facilitate a roam operation at least in part by managing compatibility issues associated with roaming between different types of networks, and for use when the remote server determines that the mobile unit is not fully compatible with the wireless local area network, a method comprising: establishing an application layer communication interaction between a first peer application program resident in the mobile unit and a second peer application layer program resident in a remote application server that is coupled to the Internet, at least partially via the cellular network, using a packet switched data transmission protocol; the mobile unit receiving, at least indirectly in response to a determination made by the remote server system in response to the indication, one or more executable software modules that are not already present in the mobile unit to be loaded into the mobile unit in order to implement a communication protocol feature used by the wireless local area network, to thereby render the mobile unit at least more fully compatible with the wireless local area network; and switching a wireless Internet access connectivity of the mobile unit from the cellular network to the wireless local area network, at least indirectly in response to the determination wherein the switching is performed at least in part, by switching at least one portion of a lower layer of a protocol stack from a cellular network air interface protocol software to a wireless local area network air interface protocol software, and the wireless local area network air interface protocol software includes at least one of the one or more executable software modules received from the remote server system; wherein the first peer application program interacts with the protocol stack at an interface point above the at least one portion of the lower layer of the protocol stack affected by the switching, so that the switching is transparent to the first peer application program, and whereby the switching is performed in a manner which results in continuity of the application layer communication interaction, to thereby provide a seamless application layer handoff as a part of the roam operation between the cellular network and the wireless local area network.