Impact of transmit range on throughput performance in mobile ad hoc networks

Mobile ad hoc networking offers the promise of connecting mobile nodes without the need for a fixed infrastructure. Performance limitations of these networks under real network and traffic conditions are still largely unknown. In this paper we present a simulation study which investigates the impact of transmit range of nodes on resulting throughput performance. Although this aspect has previously been studied analytically in stationary packet radio networks, those studies were based on a number of simplifying assumptions. Our aim is to find out the optimum transmit range to maximise data throughput in mobile ad hoc networks which use the channel contention of the 802.11 MAC layer. Contrary to the available analytical results, we find that under a wide set of network and load conditions multi-hop networks have lower performance than single hop networks. Data throughput is maximised when all nodes are in range of each other. Moreover, the addition of relay only nodes does not significantly improve throughput performance of multi-hop networks.