EURASIP Journal on Wireless Communications and Networking 
Volume 2005 (2005), Issue 5, Pages 743-756
doi:10.1155/WCN.2005.743

Cross-Layer QoS Control for Video Communications over Wireless Ad Hoc Networks

Qi Qu,1,2 Yong Pei,3 James W. Modestino,1 Xusheng Tian,1 and Bin Wang3

 1Department of Electrical and Computer Engineering, College of Engineering, University of Miami, Coral Gables 33124, FL, USA
2Department of Electrical & Computer Engineering, University of California, San Diego, La Jolla 92093-0407, CA, USA
3Department of Computer Science & Engineering, College of Engineering & Computer Science, Wright State University, Dayton 45435-0001, OH, USA
Received 21 June 2004; Revised 12 May 2005

Abstract

Assuming a wireless ad hoc network consisting of n homogeneous video users with each of them also serving as a possible relay node for other users, we propose a cross-layer rate-control scheme based on an analytical study of how the effective video transmission rate is affected by the prevailing operating parameters, such as the interference environment, the number of transmission hops to a destination, and the packet loss rate. Furthermore, in order to provide error-resilient video delivery over such wireless ad hoc networks, a cross-layer joint source-channel coding (JSCC) approach, to be used in conjunction with rate-control, is proposed and investigated. This approach attempts to optimally apply the appropriate channel coding rate given the constraints imposed by the effective transmission rate obtained from the proposed rate-control scheme, the allowable real-time video play-out delay, and the prevailing channel conditions. Simulation results are provided which demonstrate the effectiveness of the proposed cross-layer combined rate-control and JSCC approach.