by Jun De Vega and Rajshree Chabukswar

Abstract

As industry moves towards mobile computing, resources like battery life become significantly important for system usability. This paper analyzes power consumption of a laptop while transmitting compressed and non-compressed data over wireless network to determine the most power efficient method. The study focuses on how the compression ratio or size of the file affects power consumption and not on the performance of a particular compression algorithm. Recommendations for transmitting data over wireless network are presented. This study can provide guidelines to developers for writing applications that involves data transmission.

Goal

The goal of this paper is to determine the most power efficient usage model for a laptop when transferring data over wireless LAN. It helps answer questions such as: For upload, is it better to compress the data before transmission or leave it uncompress? Will a compressed file be better when downloading a file? How will the wireless adapter, CPU utilization, data compression ratio and transmission time affects the laptop power consumption? The power study is only done on the client side (laptop) and did not include the server side.

Methodology/Setup

Fluke NetDAQ* was used to measure platform power consumption while transmitting data. Different data sets were analyzed for transmitting over wireless network with and without using the compression software. Compression algorithm used here is Gzip*.

Hardware

• Target PC: Intel® Core Duo/2GHz Yonah, Customer Reference Board (CRB) with sense resistors, 2x512GB DDR2, 40GB SATA 5400 rpm (2.5” mobile), and Microsoft Windows* XP Pro SP2.


• Linksys* Router/Access Point 802.11g


• Fluke NetDAQ* (Network Data Acquisition) 2686A

• NetDAQ Logger: Fluke DAQ Software v2.2
• Compression software: Gzip* 1.2.4 (www.gzip.org*), default options