Providing Dynamic TXOP for QoS Support of Video Transmission in IEEE 802.11e WLANs

TL;DR

This paper proposes a dynamic TXOP scheduling algorithm for IEEE 802.11e WLANs that improves QoS support for variable bit rate video traffic by using piggybacked frame size information, reducing delay and enhancing transmission efficiency.

Contribution

It introduces a novel dynamic TXOP assignment algorithm leveraging piggybacked frame size data to better support VBR video traffic in IEEE 802.11e networks.

Findings

Reduces delay for VBR video streams

Improves TXOP allocation accuracy

Maintains channel efficiency for variable traffic

Abstract

The IEEE 802.11e standard introduced by IEEE 802.11 Task Group E (TGe) enhances the Quality of Service (QoS) by means of HCF Controlled Channel Access (HCCA). The scheduler of HCCA allocates Transmission Opportunities (TXOPs) to QoS-enabled Station (QSTA) based on their TS Specifications (TSPECs) negotiated at the traffic setup time so that it is only efficient for Constant Bit Rate (CBR) applications. However, Variable Bit Rate (VBR) traffics are not efficiently supported as they exhibit nondeterministic profile during the time. In this paper, we present a dynamic TXOP assignment Scheduling Algorithm for supporting the video traffics transmission over IEEE 802.11e wireless networks. This algorithm uses a piggybacked information about the size of the subsequent video frames of the uplink traffic to assist the Hybrid Coordinator accurately assign the TXOP according to the fast changes in the VBR profile. The proposed scheduling algorithm has been evaluated using simulation with different variability level video streams. The simulation results show that the proposed algorithm reduces the delay experienced by VBR traffic streams comparable to HCCA scheduler due to the accurate assignment of the TXOP which preserve the channel time for transmission.