Two preemptive polling methods with blockage sensing and signalling for indoor LOS infrared wireless LAN

The indoor infrared wireless channel is nonstationary and subject to bursty errors. In such an environment, multiple access protocols play an essential role in system performance. Two novel polling schemes are proposed, which explore the use of beam blockage sensing and signalling, and make channel reallocation according to the channel state. Compared to other classic medium access control (MAC) protocols, it has significant performance improvement on both system throughput and average transfer delay.