JOINT PRIORITY RANDOM EARLY DETECTION AND IEEE 802.11E EDCF TO SUPPORT QOS IN WLAN

During the past few years the widespread use of the wireless local area networks. (WLANs) communication technique is one of the most popular technologies in data telecommunications and networking. With the increasing variety of multimedia applications, such as voice, video and web traffic, it is needed to develop a mechanism for the quality of service (QoS) to support different types of traffic in WLAN. IEEE 802.11e EDCF is a new wireless technology to support QoS. However, EDCF never discusses the queuing issue in a station (STA) with multiple services. In this paper, we propose priority random early detection (PRED) algorithm which integrated Random Early Detection (RED) with IEEE 802.11e EDCF to support QoS in WLANs. Simulation results show that PRED algorithm, can provide better performance of access categories (ACs) with, high priority than that EDCF with traditional queuing (FIFO) strategy. Besides, we performed the parameters tuning according to the traffic load. By dynamically tuning the parameters, we can prevent throughput decreasing due to the large number of collisions under heavy traffic load condition.