A Light-Weight Client Mobility Approach for Infrastructure Mesh Networks

Infrastructure mesh networks offer a high-capacity wireless backhaul network through which clients, such as PDAs, can connect to one another or with external networks. To use the mesh network, a client must route its outbound traffic via one of the mesh routers in the infrastructure mesh. As the clients are mobile, they may move out of range of the mesh router they were using and need to associate with another. Client handoff mechanisms enable this change in mesh routers to occur in a manner that limits disruption to any transport or application layer sessions the client may be running. In this paper we present an extremely light-weight handoff approach for clients that relies on gratuitous ARP messages broadcast at regular intervals from mesh routers within the infrastructure mesh. An evaluation of our approach using a 5 node testbed has shown that client handoffs can be conducted quickly, and with minimal loss of packets for both TCP and UDP traffic.