On tree-based routing in multi-gateway association based Wireless Mesh Networks

There is an increasing acceptance for Wireless Mesh Networks (WMN) as the potential `last-mile' access technology running media-rich applications with stringent quality of service (QoS) requirements. As WMNs are envisioned to provide high bandwidth broadband services to a large community of users, the Internet Gateway which acts as a central point of attachment for the mesh routers is likely to be a potential bottleneck because of its limited wireless link capacity. We propose TBMGA (Tree-Based with Multi-gateway Association), a novel routing protocol that elegantly balances the load among the different Internet gateways in a WMN. With TBMGA, we combine the flexibility of layer-2 routing with the self-configuring and self-healing capabilities of MANET routing. TBMGA switches the point of attachment of an active source-serviced gateway depending on a global metric estimated based on the average queue length and expected availability at the Internet gateway. The protocol is evaluated using simulations and we observe that the proposed scheme is able to efficiently balance the traffic between multiple gateways.