Integrating Teams of Mobile Robots in Wireless Ad-Hoc Networks

Modern applications of mobile robot teams or robot teleoperation often demand wireless any-to-any communication in combination with highly dynamical network topologies to accomplish more and more complex tasks. These communication systems should also not rely on any pre-existing infrastructure, have low costs, and should allow for a seamless integration into existing communication networks. The well tested technology IEEE 802.11 wireless LAN offers all these possibilities. Especially the capability of realizing ad-hoc networks offers a high potential for WLAN to be used in the area of networked robots. Mesh networks and mobile ad-hoc networks are able to provide mechanisms for realizing stable communication links for networked robots. This work gives a brief overview on mesh networks and ad-hoc networks and further shows the behavior of different ad-hoc routing protocols (AODV, OLSR, DSR, BATMAN) in typical scenarios for remote operation of mobile robots. Also the differences between the application scenarios of mobile robot teams and in pure telecommunication environments are explained. The presented results are not only based on simulations. The ad-hoc routing protocols are compared in test scenarios with real mobile robot hardware experiments and the analysis is done according to well established methods and valid metrics well known from literature. Hints for the setup and parameter tuning of selected ad-hoc routing protocols are given to enable a better teleoperation of mobile robots and to improve the communication inside teams of mobile robots and humans. Finally a first approach is presented how to increase the system performance also on the application layer.