Experimental Anatomy of Packet Losses in Wireless Mesh Networks

Despite the increasing number of wireless mesh network deployments and research, there is a lack of understanding on how robust these networks are in practice. In this paper, we perform a systematic experimental study to investigate the impacts of different factors on the unreliability of a mesh network and the sources causing such unreliability. We use packet loss rate as a metric for defining reliability. The factors that we studied include traffic load, number of hops and flows, transmission rates, maximum retransmission limits and the RTS/CTS mechanism. Our results are based on measurements performed on our real- world mesh network testbed. In addition to performing the experiments on multiple hops, we include the results of one hop experiments for comparison. In identifying the sources of packet loss, we developed a tool, FlowPaC, to collect flow-based statistics at different points in the system to understand the effects of the MAC layer parameters and the traffic attributes. We also explore the potential remedies for the system configuration and thereby improve the reliability of wireless mesh networks.