Load Based Sleep Scheduling with Reduced State Transitions for IEEE 802.16e Networks

IEEE 802.16e is extensively used these days for both data and voice communications as it makes available high-speed wireless access. However, in view of the fact that mobile subscriber stations are powered by a limited capacity battery, power saving mechanism is necessary to improve network performance. In this article, the authors introduce a load based sleep scheduling mechanism with reduced state transitions for IEEE 802.16e Networks. The mechanism encompasses two phases, load-based sleep scheduling and a reduced state transition (RST) algorithm. Considering network load information, the Base Station (BS) assigns a sleep window size for each mobile subscriber station (MS). The proposed RST algorithm reduces the number of state transitions between sleep and active mode by watchfully combining any two adjacent active bands. Further, the technique considers network load and delay as QoS metrics. Through simulation results, the authors prove the proficiency of their mechanism.