An Adaptive EDCA TXOP with Rate Adaptation For QoS Provision

With the explosive growth of multimedia services in today’s wireless communications, this paper addresses the Quality of Service (QoS) issue focusing on satisfying the throughput requirement for real-time multimedia applications. An Adaptive Transmission Opportunity (AD-TXOP) scheme for a distributed Wireless Local Area Network (WLAN) system based on IEEE 802.11e Enhanced Distributed Channel Access (EDCA) mechanism is proposed. This proposed method enables an IEEE 802.11e based Quality of Service Station (QSTA) with rate adaptation capability to dynamically configure its TXOP limit within the maximum TXOP value designated by IEEE 802.11e Medium Access Control (MAC) Standard based on varying data rate and collision ratio to achieve the required QoS throughput. On top of this, our extensive simulation results clearly demonstrate that this scheme maximizes network capacity, promotes channel utilization fairness among QSTA, and ensures a more stabilized throughput performance across time. Key-Words: 802.11e, EDCA, TXOP, Rate Adaptation, QoS