WiCTP: A token-based access control protocol for wireless networks

The introduction and growth of large, metropolitan-sized wireless networks has identified a significant problem within the current 802.11 protocol specification, hidden nodes. Hidden nodes dramatically decrease performance and throughput of networks where they are present, and the current solution, RTS/CTS leaves much room for improvement. This paper proposes a new, token-based protocol called WiCTP that can be implemented on top of standard CSMA/CA, but which enables any higher level protocol to be used with it. WiCTP successfully improves network stability and throughput in wireless networks where hidden nodes may be present. The overhead of the WiCTP protocol in terms of the overall bandwidth used is small. We discuss an implementation of the WiCTP protocol as a Linux kernel module and experimental results from its implementation in a metropolitan-sized wireless network.