Performance evaluation of a link adaptation scheme in IEEE 802.11e over IEEE 802.11a WLANs with QoS support

Abstract Wireless Local Area Networks (WLANs) represent a powerful technology for accessing data, voice and video services in mobility. The literature dealing with IEEE 802.11 WLANs optimisation for supporting real‐time services performance is plentiful. IEEE Task Group E has been created with the aim of enhancing the Quality of Service (QoS) capabilities of the MAC IEEE 802.11, while several link adaptation algorithms have been proposed to optimise the rate selection in the IEEE 802.11a physical layer. In this work, the knowledge of the application type, provided by the MAC IEEE 802.11e layer, is exploited in a link adaptation strategy for the PHY IEEE 802.11a layer. The performance of the system is studied by using an event‐driven simulator, which implements the specifications of the IEEE 802.11e draft standard and the IEEE 802.11a standard. Simulation results show that the proposed scheme achieves both the link adaptation advantages and the required QoS support to real‐time services. Copyright © 2005 AEIT.