An ad-hoc routing protocol with minimum contention time and load balancing

In spite of using IEEE 802.11 as medium access control (MAC), most of the ad-hoc routing protocols do not consider contention time that occurs in the medium reservation procedure. Large, contention times can be more critical than hop counts in determining the end-to-end delay. In ad-hoc networks, traffic concentration on some mobile nodes leads to long queuing delays, low packet delivery ratios, and inefficient power consumption. In this paper, we propose an ad-hoc routing protocol with minimum contention time and load balancing (MCL). MCL has two main characteristics. Firstly, MCL selects a route with minimum contention among many possible routes between source and destination in the route selection procedure; secondly, intermediate nodes do not reply to RREQs in the route discovery procedure. These characteristics reduce contention time in medium reservation procedure and distribute traffic throughout the network. We have compared the proposed MCL and the ad-hoc on-demand distance vector (AODV) routing protocol. Simulation results show that MCL outperforms AODV in terms of packet delivery ratio, average end-to-end delay, and normalized routing overhead. In situation where several mobile nodes send data to a fixed node such as an access point or a server, our proposed routing protocol MCL delivers a high performance gain as a result of load balancing.