Delay-aware Load Balanced Routing Protocol for IEEE 802.16 Wireless Mesh Networks

In IEEE 802.16 Wireless Mesh Networks (WMN) routing, delay aware load balancing can be achieved by selecting the shortest path with low latency and network load. But network load and latency together are not considered in most of the existing routing metrics. Here, we propose a delay aware load balanced routing protocol for wireless mesh networks by designing a combined route metric. Initially, we calculate the metric of traffic interference (TIM) which considers the traffic load of interfering neighbors. Next, we calculate the metric for end to end service delay (EDM) by using the expected time spent in transmitting all packets waiting for transmission through a link. This metric can be used to select the path with the lowest end-to-end service delay in terms of current network load. Using these two metrics we define a combined route metric for efficient route selection. A route discovery mechanism is proposed which broadcasts request packets along with expected link delay and load value. The suitable path is selected based upon the least routing metric value. A route maintenance mechanism is also proposed to maintain the stability of the network. Using this, frequent changes in the path can be avoided and transmission efficiency is increased. By simulation results, we show that the proposed protocol reduces the delay and overhead there by increasing the overall packet delivery ratio, when compared with existing protocols.