Feasible HCCA Polling Mechanism for Video Transmission in IEEE 802.11e WLANs

TL;DR

This paper proposes an enhanced HCCA polling mechanism for IEEE 802.11e WLANs that improves video stream scheduling by using cross-layer feedback, resulting in reduced delay and higher throughput for VBR videos.

Contribution

It introduces a novel polling enhancement that incorporates frame arrival feedback to better schedule VBR video streams in IEEE 802.11e networks.

Findings

Reduced delay in video transmission.

Increased throughput for VBR streams.

Fewer wasted polls and null-frames.

Abstract

IEEE 802.11e standard defines two Medium Access Control (MAC) functions to support Quality of Service (QoS) for wireless local area networks: Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA provides fair prioritized QoS support while HCCA guarantees parameterized QoS for the traffics with rigid QoS requirements. The latter shows higher QoS provisioning with Constant Bit Rate (CBR) traffics. However, it does not efficiently cope with the fluctuation of the Variable Bit Rate (VBR) video streams since its reference scheduler generates a schedule based on the mean characteristics of the traffic. Scheduling based on theses characteristics is not always accurate as these tra_cs show high irregularity over the time. In this paper, we propose an enhancement on the HCCA polling mechanism to address the problem of scheduling pre-recorded VBR video streams. Our approach enhances the polling mechanism by feed-backing the arrival time of the subsequent video frame of the uplink traffic obtained through cross-layering approach. Simulation experiments have been conducted on several publicly available video traces in order to show the efficiency of our mechanism. The simulation results reveal the efficiency of the proposed mechanism in providing less delay and high throughput with conserving medium channel through minimizing the number of Null-Frames caused by wasted polls