Improving optical wireless links for internet applications

This paper aims at improving the performance of Internet applications over error-prone wireless links. Due to many attractive aspects, infrared is chosen as the wireless medium in the research. The characteristics of a diffuse infrared channel are detailed presented and the simulation model in network simulator ns-2 is described. The tests on the performance of Internet protocols, TCP and UDP, indicate that error recovery schemes are required when the channel becomes severe. The link layer error recovery schemes, XOR-FEC and GBN-ARQ are proposed. As the deployment of WLAN indicates that the future networks will support multimedia services, in the simulations both real-time and no-real-time applications are studied. To evaluate the performance of the error recovery schemes, simulations are performed with both voice conversation and file transfer applications. The results show that it may be a good idea to provide diverse error recovery services based on the QoS requirements of the applications.