[pi]Mesh : practical implementation of a low-cost wireless mesh for indoor networking

Wi-Fi access technology has become popular in recent years. Many users nowadays use Wi-Fi solution to gain wireless access to the Internet from offices, public libraries, shopping malls, homes and so on. However current Wi-Fi deployment is limited to the areas where wired LAN is available. Due to its relatively short transmission range in indoor environment, which is typically several tens of meters, Wi-Fi coverage needs to be extended significantly to give full coverage of a certain area. Wireless mesh networks (WMNs) have emerged as an effective solution to address this problem. WMNs consist of mesh routers and mesh clients, where mesh routers form the backbone of WMNs and have limited mobility. Mesh clients can be either stationary or mobile and get Internet access through the relay of mesh routers. In this thesis, we present πMesh, a practical implementation of wireless mesh networks for indoor environments. πMesh is based on simple protocols, implementable in normal notebooks or PCs and is compatible with existing Wi-Fi AP and Wi-Fi clients (i.e., no AP and client modifications). It requires no extra hardware and uses existing noproprietory off-the-shelf technology to build a cost-effective indoor wireless mesh. To achieve better end-to-end delay and throughput, πMesh dynamically selects its access path based on the ETX metric. Simulations show ETX achieves better throughput than the hop-count metric. We also implemented πMesh and conducted proof-of-concept experiments in an indoor environment