Load balanced multiple gateway support in wireless mesh networks for broadband services

In this paper, we present our design and implementation of Load-Balanced Gateway Discovery Routing Protocol called LBGD-AODV. A gateway node in a wireless mesh network acts as bridge between mesh routers and external network in order to provide services such as broadband. We observed in our SwanMesh testbed that a single gateway can only serve up to a limited number of hops due to noticeable throughput drop at each hop. LBGD-AODV solves the problem by supporting multiple gateways. Our proposed LBGD-AODV advertises a new gateway to the network by broadcasting a periodic gateway hello control message after every GATEWAY_HELLO_INTERVAL milliseconds. When a gateway hello message travels through the network it helps all mesh nodes on the network to learn more information about the network topology. This information includes hop count to each gateway on the network, load on each gateway and local load on each mesh router. Mesh routers use this information to select an appropriate gateway with an appropriate route to communicate to the external network. Thus apart from the gateway discovery LBGD-AODV performs load balancing using the single process. Test results performed using SwanMesh shows that apart from the multiple gateway environment, load balancing support also increased throughput performance between mesh routers and gateways to external networks.