Leveraging Pseudo-TDMA to a Controllable and Bandwidth-Efficient Village Area WiFi Networks
Xi Chen, Zhenyu Chen, Yaohui Wu · 2008
The cost-effectiveness of WiFi makes it much attractive for large residential area coverage that is potentially competitive to DSL. Existing WiFi chipsets often implement IEEE 802.11e CSMA/CA enhanced distributed channel access (EDCA) function only, because the point coordination function is seldom required in typical applications. To build a controllable and bandwidth-efficient WiFi DSL, it not only means extending communication range by enlarging RF power or using directional antenna, but also needs a protocol enhancement at the MAC layer. In this work, we propose a Pseudo-TDMA (pTDMA) controlled access protocol over EDCA function, which was applied in our village area WiFi network testbed. It can be implemented by adding a software enhancement into the commercial off-the-shelf chipsets. In addition to the stability and controllability inherent to TDMA, simulation results reveal that the proposed protocol has an obvious saturation throughput improvement over existing IEEE 802.11e EDCA function when the packet size is big enough.