Efficient intra-access category prioritization technique over the IEEE 802.11aa standard

Abstract

Intra-Access category prioritization is a new technique that has been proposed by IEEE 802.11aa standard to further enhance the granularity and reliability for real-time Audio Video (AV) streams. However, Intra-AC prioritization introduces a new Credit-Based Shaper Algorithm (CBSA) utilizing as a scheduling algorithm between the primary and alternative queues that may lead to lack of graceful throughput degradation of AV streams quality. Typical CBSA has been standardized by IEEE 802.1Q in Audio Video Bridging (AVB) to provide low latency and fair data transmission services. However, the CBSA that utilizing in Intra-AC prioritization mechanism still provides low efficiency in particular at non-real-time data transmission services. Non-optimal CBSA formal selecting parameters still exist thus leading inefficient throughput utilization of data transmission services. The main objective of the research is to propose and implement efficient Intra-Access category prioritization technique over the IEEE 802.11aa standard. Firstly, A Novel Per-class resource reservation Quality of Service (QoS) is proposed and implemented, based on the Intra-AC prioritization 802.1Q standard. Secondly, A Novel CBSA formal parameters optimization based on measurement classes interval of CBSA 802.1Q and its utilization is introduced to dynamically estimate the appropriate formal parameters values for each class (Class A and Class B) independently. Thirdly, the proposed method unified the three mechanisms between wired and wireless technology in the sublayer of Medium Access Control (MAC): the maps Access Categories (ACs), the transmit access queues and Transmission Selection Algorithm (TSA). Moreover, this proposal solution provides a fairness throughput for non-real time traffics, the nonreal- time traffic generation rate is allowed to adapt itself to the underlying network load conditions. Finally, the network simulation model Enhanced distribution Channel Access (EDCA) 802.11e is developed and modified on the Network Simulator (NS) 2.35 which is used to investigate the impact of real-time video, non-real-time video, and best effort traffic on the performance of the proposed Intra-AC prioritization in 802.11aa standard. The simulation results show that the proposed solution outperformed the existing standard in all the three-performance metric normalized throughput, frame loss ratio, and average latency for the primary and alternative video queues. Normalized throughput of the video primary and alternative queues are improved by (25.9%) and (8.3%) respectively, the frame loss ratio is enhanced by (5.82%) and (1.02%) and the average latency is improved by (20.40%) and (7.46%)