IEEE 802.11E QoS and power saving features overview and analysis of combined performance [Accepted from Open Call]

Wireless LAN has become the ubiquitous connectivity solution for computing in the home and hotspot environments. While the technology continues to grow within its core computer market, it is also steadily expanding into the much larger handset and consumer electronics markets. Given the increasingly diverse range of applications, additional requirements need to be met by products in order to ensure user satisfaction. Within these requirements two are commonly shared by most new devices: QoS support for prioritizing real-time services over non realtime and power saving functionality to achieve an operating time meeting users¿ expectations. In this article we first provide an overview of the two power saving modes defined by IEEE 802.11e, unscheduled, and scheduled automatic power save delivery, followed by an evaluation of the performance of the different possible combinations of IEEE 802.11e QoS and power saving mechanisms compared to the legacy 802.11 medium access protocol and power save mode. Our results show the level at which the 802.11e QoS and power saving mechanisms meet their design objectives, and provide quantitative results on the differences to be expected with respect to QoS, power saving, signaling load, and network capacity in a generic scenario.