Energy-Efficient Video Transmission Over a Wireless Link

Energy minimization is an important design goal in wireless video transmission. We examine how the RF energy and the analog circuit energy, which account for a large part of the energy consumption for wireless video transmission, can be controlled with physical-layer parameters (e.g., modulation level, bit rate, bit error rate, and multiple access interference) and link-layer specifications (e.g., the buffer status, idle time, and active time). Building on these insights, we develop three energy-efficient video transmission schemes for the single-user system, i.e., frame-by-frame transmission, group of pictures (GOP)-by-GOP transmission, and client-buffer-related energy-efficient video transmission (CBEVT). Our simulations indicate that energy savings of up to 85% is achievable in the radio frequency (RF) front end using the CBEVT algorithm. We also present an energy-efficient optimal smoothing algorithm for reducing the RF front-end energy consumption and the peak data rate. For CDMA-based multiuser systems, we propose an RF front-end energy model that assumes perfect power control. We find the signal-to-interference-noise ratio (SINR) for the entire system that minimizes the total energy consumption. We propose the multiuser-based energy-efficient video transmission (MBEVT) algorithm, which can achieve energy savings of up to 38% for a six-user CDMA system with an independent 16-MB buffer for every uplink.

I. Introduction

Wireless multimedia services, which are growing in popularity, pose several challenges, including overcoming bandwidth variations and limited battery lifetime. Although the next-generation wireless technologies promise more reliable communication and higher bandwidth, the problem of high energy consumption during video transmission is largely unresolved. In this paper, we develop wireless video transmission schemes that ensure the timely delivery of the video frames while saving energy.