Performance Analysis of Power Save Mode in IEEE 802.11 Infrastructure WLAN

For the battery-powered wireless stations, power saving is one of the significant issues in IEEE 802.11 wireless local area network (WLAN). Recently, Lei and Nilsson investigated power save mode in IEEE 802.11 infrastructure network by an M/G/1 with bulk service where they obtained mean packet delay and bound of the average Percentage of Time a station stays in the Doze state (PTD). In this paper, the further investigation of power save mode is done; simple derivation of the mean and the variance of packet delay and the exact value of PTD are obtained. Numerical results show that our analytic results for PTD match quite well with simulation results by Lei and Nilsson. Using our performance analysis, we can find the maximal listen interval which maximizes the average PTD of a station while satisfying the required quality of service (QoS) on the mean and the variance of packet delay.