Efficient transmission of MPEG-2 video bit streams over HIPERLAN/2

Abstract

This paper studies the transmission of MPEG-2 video bit streams over HIPERLAN/2 based wireless local area networks (WLANs). HIPERLAN/2, a WLAN standard introduced by ETSI (the European Telecommunications Standards Institute), is well known for its ability to operate under different physical (PHY) modes (modulation schemes) and adaptively switch its modes within a single transmission session. Each physical mode has certain throughput and error resilience associated with it. The presence of multiple physical modes can be exploited to achieve Quality of Service (QoS) guarantees for application parameters such as throughput, bit error rate (BER), jitter etc. In this paper, we first study the relationship of different PHY modes with BER and throughput. Based on this study, different content based marking algorithms are presented and analyzed that partitions the input video bitstream into multiple segments, where each segment is deemed suitable for transmission over HIPERLAN/2 operating under a specific PHY mode. We show that for a given video bit stream, the use of multiple PHY modes chosen based on the characteristics of underlying video data yields superior throughput and better picture quality in terms of pixel signal to noise ratio (PSNR). From the power consumption point of view, the marking algorithms can achieve desired throughput or PSNR with lower signal to interference ratio (SIR) levels thus saving battery power and extending the overall battery life. Copyright © 2004 John Wiley & Sons, Ltd.