Effective Routing Scheme through Network Load-aware Route Metric in Multi-rate Wireless Mesh Networks

Abstract

In multi-rate wireless mesh networks, a mesh node can dynamically modify the data rate on a particular link, in response to the perceived SNR ratio between neighbor nodes. In such networks, existing route selection schemes use a link quality metric based on the expected amount of medium time it takes to successfully transmit a packet. However, these schemes do not take into account the status of network load. Therefore, they may easily result in the network being overloaded. In addition, the application has no way of improving its performance under given network traffic conditions. In this paper, a new route metric that considers both per-hop service delay, estimated using the number of packets waiting for transmission in the output queue at relay nodes, and link quality is proposed. In addition, we propose the network load-aware AODV (NLA-AODV) protocol using the proposed metric. This protocol is implemented in a straightforward manner. The performance evaluation is performed by simulation using OPNET. It is demonstrated that the performance of the routing protocol using the proposed route metric outperforms routing protocols using other existing route metrics in multi-rate wireless mesh networks.