A survey of quality of service in IEEE 802.11 networks

TLDR

IEEE 802.11, a simple and cost‑effective wireless technology, has become widely popular, yet its lack of built‑in QoS support hampers meeting multimedia service demands. The article surveys 802.11 QoS schemes—service differentiation, admission control, bandwidth reservation, and link adaptation—to address these challenges. It examines MAC‑layer service differentiation, admission control, bandwidth reservation, and physical‑layer link adaptation, and discusses end‑to‑end QoS issues such as protocol interoperability, multihop scheduling, full mobility support, and seamless vertical handoff in heterogeneous wired‑wireless networks.

Abstract

Developed as a simple and cost-effective wireless technology for best effort services, IEEE 802.11 has gained popularity at an unprecedented rate. However, due to the lack of built-in quality of service support, IEEE 802.11 experiences serious challenges in meeting the demands of multimedia services and applications. This article surveys 802.11 QoS schemes, including service differentiation in the MAC layer, admission control and bandwidth reservation in MAC and higher layers, and link adaptation in the physical layer, designed to meet these challenges by providing the necessary enhancements for the required QoS. Furthermore, the article addresses issues that arise when end-to-end QoS has to be guaranteed in today's pervasive heterogeneous wired-cum-wireless networks. Among these challenges, protocol interoperability, multihop scheduling, full mobility support, and seamless vertical handoff among multiple mobile/wireless interfaces are specifically addressed.