Improving the Usable Capacity of Ad Hoc Networks

Abstract

Recent research has shown that multi-hop ad hoc networks suffer from a low capacity and moreover that an individual node's capacity for long-distance communication decreases the more nodes are participating in the ad hoc network. The usable capacity of ad hoc networks is further decreased by the forwarding metric of usual routing protocols, which try to minimize the number of hops or try to minimize the remaining distance to the receiver. This results in traffic concentration at one or several areas in the network, what we will refer to as network center(s), and thus in a decreased usable capacity. Especially in the automotive domain, where road infrastructure and road traffic flow frequently create network centers, solving this issue is of particular interest.

In this paper we will show that the network center is indeed a bottleneck for communication which limits a network's capacity. Then we will present a new forwarding approach, which relieves the network center from handling an excessive part of the traffic. Instead of just trying to minimize the distance to the receiver, this approach additionally tries to avoid routing through the network center. Simulation results show, that the usable capacity of the ad hoc network is increased with this approach by approximately 30%.