A dynamic topology switch for the emulation of wireless mobile ad hoc networks

Wireless mobile ad hoc networks differ from wired networks in that their topologies are highly dynamic and their links can have a relatively high bit error rate. These properties make it difficult to conduct controlled, repeatable experiments with routing and other protocols in a wireless ad hoc network environment. To address this problem, we have developed a switch that connects multiple unaltered hosts according to a controllable dynamic topology with a controllable bit error rate on the links. The dynamic topology switch emulates a wireless mobile ad hoc network using standard Ethernet physical connections. This allows researchers to experiment with routing and other protocols in a mobile ad hoc network (MANET) environment. In this paper, we describe our dynamic topology switch and describe the validation of the switch. We validate the switch by comparing control packet overhead for the optimized link state routing (OLSR) protocol measured using the switch and using the ns-2 simulator.