Adaptive Power Saving Algorithm for Mobile Subscriber Station in 802.16e

WiMAX standard for mobility (IEEE 802.16e) addresses the issues related to energy conservation at Mobile Subscriber Station (MSS) in sleep mode. In 802.16e the sleep mode is exponentially distributed according to traffic, The algorithm that deals with sleep mode energy consumption in 802.16e network does not address the problem of varying traffic rates. This paper proposes an adaptive sleep mode interval control algorithm for 802.16e, which takes into account the downlink traffic pattern to minimize energy consumption. Moreover, we characterize the standardized sleep mode in IEEE 802.16e MSS taking into account various situation like, moving into sleep, listening or wake-up modes. It has been observed that our proposed algorithm for sleep mode saves substantial amount of energy at lower traffic and almost same at higher traffic as compared to 802.16e. The results reveal that the optimization of sleep mode leads to decrease in average waiting time delay at MSS. Furthermore, our analytical evaluations are close to simulation results.