Using Commodity Hardware Platform to Develop and Evaluate CSMA Protocols

Developing and evaluating wireless protocols is challenging because it requires flexible network interface hardware, which is not readily available. In this paper, the authors present FlexMAC, a wireless protocol development and evaluation platform based on commodity hardware. FlexMAC targets CSMA wireless protocols and allows customization of functions such as backoff, retransmission, and packet timing. They describe their implementation of FlexMAC and quantify FlexMAC's precision for 802.11b compared with commercial hardware implementations. The results show that FlexMAC's performance is very close to that of hardware implementations. They also present two case studies that illustrate FlexMAC's flexibility: the use of opportunistic relaying to boost throughput and an investigation of temporal and throughput fairness.