Increasing Connectivity of Ad-Hoc Networks

Mobile Ad-Hoc networks are built spontaneously from mobile devices communicating via wireless interfaces. The idea is that some of the devices act as relay stations in such a way that two stations, which are not in direct range, can communicate with each other over this new multi-hop connection. However, the nature of Ad-Hoc networks and especially the mobility of nodes makes it difficult to achieve a certain minimum connectivity, which is an indispensable property for reliable communication. With our simulation tool ANSim (Ad-Hoc Network Simulator), we have already shown that with randomly moving nodes (a realistic assumption) one needs many mobile devices to achieve an acceptable connectivity. In this paper, we therefore investigate the idea of introducing mobile robots to such a network, whose only function is to act as a relay station thus not to fulfil any application-specific task. The robots have to find out the optimal position in the network, i.e., the place where they can best support application-oriented devices in their work. In this first approach we assume that the robots have full knowledge of the positions of all other devices. We simulate their behaviour in this situation. The results indicate that further work on this idea will be worthwhile.