| Video quality based link adaptation for low latency video transmission over WLANs |
| |
| 作者姓名： | FERR Pierre DOUFEXI Angela CHUNG-HOW James NIX Andrew BULL David |
| |
| 作者单位： | University of Bristol Department of Electrical and Electronic Engineering Centre for Communications Research Bristol BS8 1UB UK，University of Bristol Department of Electrical and Electronic Engineering Centre for Communications Research Bristol BS8 1UB UK，ProVision Communication Technologies Bristol BS4 4EU UK，University of Bristol Department of Electrical and Electronic Engineering Centre for Communications Research Bristol BS8 1UB UK，University of Bristol Department of Electrical and Electronic Engineering Centre for Communications Research Bristol BS8 1UB UK |
| |
| 摘 要： | INTRODUCTION Low latency video transmission is very de manding in terms of the performance of all layers i the protocol stack. Over the last decade, research ha focused on enhancements of each individual laye without considering cross-layer interactions. Adapt ing video coding to the channel/network condition and technologies (and vice versa) (Girod et al., 2002 via the cross-layer exchange of information has onl recently been investigated. van der Schaar et al.(200 developed a cross-laye…
|
| 收稿时间： | 2 December 2005 |
| 修稿时间： | 17 February 2006 |
Video quality based link adaptation for low latency video transmission over WLANs |
| |
| Pierre Ferré,Angela Doufexi,James Chung-How,Andrew Nix,David Bull.Video quality based link adaptation for low latency video transmission over WLANs[J].Journal of Zhejiang University Science,2006,7(5):847-856. |
| |
| Authors: | Pierre Ferré Angela Doufexi James Chung-How Andrew Nix David Bull |
| |
| Institution: | (1) Department of Electrical and Electronic Engineering, Centre for Communications Research, University of Bristol, Bristol, BS8 1UB, UK;(2) ProVision Communication Technologies, Bristol, BS4 4EU, UK |
| |
| Abstract: | Wireless Local Area Networks (WLANs) such as IEEE 802.11a/g and Hiperlan/2 utilise numerous transmission modes, each providing different throughputs and reliability levels. Many link adaptation algorithms proposed in the literature either maximise the error-free data throughput based on channel conditions or are based on the number of failed transmissions. However, these algo- rithms do not take into account the content of the data stream and strongly rely on the use of Automatic Repeat Requests (ARQs). Low latency video applications such as real-time video transmission may require no retransmission, or only a limited number of retrans- missions. Moreover, completely error-free communication is not essential, especially if robust video compression techniques are applied. In such scenarios, improved decoded video quality can be obtained with a video stream transmitted at a higher bit rate using a higher link speed but with some degree of transmission error, rather than an error-free video stream at a lower bit rate using a lower link speed. In this work, we investigate a link adaptation scheme that improves the Quality of Service (QoS) for video transmission, based on the overall received video quality (Peak Signal to Noise Ratio, PSNR), rather than by maximising the error-free throughput. We also study a practical link adaptation approach that uses PER thresholds at the PHY layer. An empirical study showed that thresholds for switching from one mode to another are much lower (almost error free) than those currently used by throughput based schemes. We show that traditional link adaptation strategies are not appropriate for real-time video transmission with no retransmis- sion. Simulation results using the H.264 video compression standard over IEEE 802.11a are presented. |
| |
| Keywords: | Link adaptation Wireless LAN Video quality Peak Signal to Noise Ratio (PSNR) Packet Error Rate (PER) |
| 本文献已被 CNKI 万方数据 SpringerLink 等数据库收录！ |
