EDCA (Enhanced Distributed Channel Access), developed for providing service differentiation in wireless LANs, has become a MAC standard in IEEE 80.2.11e. However, unexpected packet delay due to collisions and retransmissions may occur when the wireless LAN becomes congested. To support the increasing demand of delay-sensitive multimedia applications, this paper presents a modified EDCA with dyn...

A model of the IEEE 802.11e EDCA function is presented. The model is built to be simple, but providing a clear description of the inter-relations between the EDCA MAC parameters (AIFS, CWmin, CWmax and TXOP values) and the traffic flow characteristics (packet arrival rate and packet length). The model is intended to be used as an abstraction of the IEEE 802.11e MAC protocol in WLAN flow level s...

IEEE 802.11p Vehicular Ad-Hoc Network (VANET) applies one control channel (CCH) and six service channels (SCHs). CCH is dedicated for broadcasting traffic safety messages, SCHs are dedicated for transmission of varying application messages. In IEEE 802.11p standard, Coordinated Universal Time (UTC) scheme is recommended for coordinating channel access on CCH and multiple SCHs, Enhanced Distribu...

Wi-Fi or wireless local area networks (WLANs) are among the most popular wireless internet access technologies used. The major challenge faced by WLANs is the provision of quality of service (QoS) for real-time applications at high congestion periods. IEEE 802.11e draft presents the only comprehensive QoS infrastructure for WLANs which proposes enhanced distributed channel access (EDCA) that pr...

Contention Free Burst (CFB) is a promising burst transmission scheme defined in the IEEE 802.11e Medium Access Control (MAC) protocol to achieve differentiated Quality of Service (QoS) and improve the utilization of the wireless scarce bandwidth. Although modeling and performance analysis of the IEEE 802.11e network have attracted tremendous research efforts from both the academia and industry,...

Wireless LANs are increasingly being used for inelastic applications. Currently, there is little support for quality of service in the IEEE 802.11 MAC protocol, and IEEE task group E has defined the 802.11e MAC extension. Enhanced distributed channel access (EDCA) is a contention-based scheme of the 802.11e standard. To allow a station to transmit more than one frame from a single contention, a...

Abtract. The IEEE 802.11e draft standard is a proposal defining the mechanisms for wireless LANs aiming to provide QoS support to time-sensitive applications. However, recent studies have shown that the IEEE 802.11e (EDCA) performs poorly when the medium is highly loaded due to the high collision rate. Even though several proposals have been proposed to address this problem, they require import...

Face recognition is the process of categorizing a person in an image by evaluating with a known face image library. The pose and illumination variations are two main practical confronts for an automatic face recognition system. This study proposes a novel face recognition algorithm known as Efficient Discriminant Component Analysis (EDCA) for face recognition under varying poses and illuminatio...

This paper considers proportional fairness amongst ACs in an EDCA WLAN for provision of distinct QoS requirements and priority parameters. A detailed theoretical analysis is provided to derive the optimal station attempt probability which leads to a proportional fair allocation of station throughputs. The desirable fairness can be achieved using a centralised adaptive control approach. This app...