QoS-Enabled Power Saving Access Points for IEEE 802.11e Networks

IEEE 802.11 is now being used in many situations where access point (AP) power saving would be highly desirable. Unfortunately, this is not possible since the existing standard requires that APs remain active at all times. In this paper, we present a framework for a power saving quality-of-service (QoS) enabled access point (PSQAP), intended for use in low power infrastructure applications. The proposed scheme introduces infrastructure based power saving while preserving the QoS requirements for delay and loss intolerant real-time applications. Using an extensive simulation study we have evaluated the integrated framework, which consists of a proposed energy efficient media access control (MAC) protocol and an adaptive connection admission control (CAC) scheme. Our results show that the power consumption at PSQAPs can be significantly reduced without violating any of the QoS requirements for real-time traffic streams. The effect on power saving at the stations is also reasonable and can be controlled via protocol specific parameters.