Patent ID: 7228355

Claim:
For use in a system comprising a cellular network and a wireless local area network coupled to an Internet, a method comprising: establishing a voice telephony call between a mobile unit and a remote voice telephony endpoint, via the cellular network, using a circuit switched cellular telephony protocol for at least a wireless leg of the voice telephony call; receiving from a remote server system an indication to automatically switch a wireless access portion of the voice telephony call from the cellular network, to the wireless local area network; and in response to the indication, switching the wireless access portion of the voice telephony call from the cellular network to the wireless local area network, wherein after the switching, at least the wireless access portion of the voice telephony call uses a voice-over-Internet telephony protocol; wherein the switching is performed while maintaining a voice connectivity with the remote voice telephony endpoint, to thereby provide a seamless call handoff from the cellular network to the wireless local area network.