Abstract: A method of roaming between access points on the same or different wireless networks using a single wireless network interface adaptor. A device will establish a connection with a second wireless network access point while still connected with a first wireless network access point such that the device can concurrently communicate with both wireless access points. During and after connection with the second wireless network access point real-time IP data transfer is maintained with another network device by switching between the first and second access points for concurrently sending and receiving data packets via both access points using a switching strategy based at least in part on a number of the data packets to be send to each network access point. The method also determines when to roam, scans for candidate wireless network access points to connect to and selects the best access point for roaming based on selection criteria.

Abstract: A method of improving communication in a SIP-enabled communication network which involve a variety of communication devices. By the method, a call, either entirely or just a selected medium stream of the call, may be switched, easily and seamlessly to a different channel for different media, either on the same device or on a separate device connected to the network, either during call-setup or after a call session has been established. The call may also initiate a application sharing session so that caller, callee and those participated in the call (in conference mode) may see the content of the same document or whiteboard on a screen while keeping voice communication over the phone.