Implementation and Evaluation of a TDMA MAC for WiFi-based Rural Mesh Networks ∗

WiFi mesh networks with outdoor links have become an attractive option to provide cost-effective broadband connectivity to rural areas, especially in developing regions. It is well understood that a TDMA-based approach is necessary to provide good performance over such networks. While preliminary prototypes of TDMA-based MAC protocols have been developed, there is no implementation-based validation/evaluation in multi-hop settings. In this work, we describe the elements of a multi-hop MAC implementation based on the open-source MADWIFI driver. We also present an evaluation, with a detailed accounting of the various overheads, on a 4-hop (5-node) path. We show that our implementation has no system overheads, achieves good throughput, and low delay/jitter.