Seamless connectivity and mobility in wireless mesh networks

Wireless mesh networks extend the connectivity range of mobile devices by using multiple access points, some of them connected to the Internet, to create a mesh topology and forward packets over multiple wireless hops. Mobile clients should be able to freely roam within the area covered by the mesh and maintain their connectivity at all times.;This thesis presents the architecture and protocols of the first transparent wireless mesh system that offers seamless, fast handoff, supporting VoIP and other real-time application traffic for any unmodified 802.11 device. The entire mesh network is seen by the mobile clients as a single, omnipresent access point. Access points continuously monitor the connectivity quality of any client in their range and efficiently share information with other access points in the vicinity of that client to coordinate and decide which of them should serve the client. We first show an intra-domain handoff protocol that transfers connectivity between the access points serving the mobile device. We then show an inter-domain handoff protocol that transfer connectivity between access points connected to the Internet. Both handoffs, which can occur simultaneously, maintain all previously opened connections while transferring them as fast as possible without any involvement from the mobile device. Experimental results on a fully deployed mesh network demonstrate the effectiveness of the architecture and its handoff protocols.