Performance evaluation of routing protocols for Wireless Mesh Networks

Abstract: Wireless Mesh Networks provide an organisation or a community with the means to extend or create a network independent of infrastructure. However, the network’s dynamic topology along with the fact that devices in the network might be mobile and move randomly, brings tolight various kind of problems on the network, with the most common being the routing. In this report, the problem of routing is examined in terms of throughput, routing overhead, end-to-end delay and packet delivery ratio on two chosen algorithms, namely the Dynamic MANET On-demand (DYMO) and the Better Approach To Mobile Adhoc Networking (B.A.T.M.A.N.). Furthermore, this thesis examines also a Transmission Control Protocol (TCP) connection and compares it against several TCP congestion control mechanisms, two of which, were implemented, namely TCP-Illinois and TCP-FIT, to address the effects that different TCP congestion mechanisms have on an ad-hoc network, when reliable connections are needed. The results show that DYMO is more stable, performs good overall and has the lowest routing overhead, however in a situation with limited mobility or no mobility (as in high mobility they perform poorly) proactive protocols like B.A.T.M.A.N. are worthy protocols, should the extra penalty of routing overhead in the network traffic is not causing any problems. Furthermore, regarding the TCP results, it was observed that TCP congestion algorithms designed specifically for Wireless networks, do offer better performance and should be considered, when designing an ad-hoc network.