Improving performance in TDMA over Wifi-PHY mesh Networks for Rural Internet Connectivity

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The Internet has become an essential part of our daily lives. However, still a significant fraction of the population, especially in rural regions in the developing world, lack access to the Internet. The cost economics is the key reason for this digital divide, as conventional technologies for providing Internet access are not cost effective. In this talk I will highlight the use of “TDMA over WiFI-PHY” mesh networks for providing low cost Internet connectivity. Commodity WiFi hardware is available for cheap and so WiFi mesh networks are an attractive low cost option for Internet connectivity. However the disadvantage of WiFi mesh networks is that the conventional 802.11 CSMA/CA based MAC protocol does not work efficiently in mesh network scenarios. To alleviate this, we have considered the use of TDMA MAC protocol for mesh networks. TDMA MAC protocol does not make use of contention based access as in CSMA/CA MAC protocol and so can provide guaranteed QoS performance. To leverage the low cost benefit of commodity WiFi hardware, we have implemented the TDMA MAC protocol, in software, on top of commodity hardware. We term such networks as “TDMA over WiFi-PHY” mesh networks as for these, PHY layer is that which is specified by WiFi standard but MAC protocol is modified to TDMA MAC protocol. There are several challenges associated with TDMA over WiFi-PHY mesh networks, before these can be practically realized. In this talk I will highlight these different challenges and solutions that we have devised for realizing such networks for low cost Internet connectivity.

Vishal Sevani, DeNovo Group

Vishal Sevani received his B.E in Electronics Engineering and M.E in Electronics and Telecommunication Engineering from Mumbai University (India) in 2002 and 2006 respectively. After completing his Masters, he worked as a Software Engineer for two years. He then joined Computer Science and Engineering Dept. of Indian Institute of Technology, Bombay (India) to pursue his PhD. After PhD, he worked for about a year as a guest researcher in NIST, USA focussing on 5G networks. For the past three years, he has been working for DeNovo Group, helping them in their goal to provide Internet connectivity to rural California. His research interests are broadly in the area of systems and networking.