Power Management in Mobile Computing (a Survey)

Abstract Rapid advances in technology have resulted in laptop (mobile) computers with performance and features comparable to desktop (stationary) machines. Advances in rechargeable battery technology have failed to keep pace, decreasing the usefulness of mobile computers and portable wireless devices. Several methods of power management can be used to prolong the battery life of a mobile computer. We provide a detailed analysis of power consumption typically encountered in a networked laptop com- puter and the power management methods currently used. We also outline some novel proposed power management methods. 1 Introduction Laptop computers have often served as portable word processors or game machines. Such machines were generally two or more generations behind desktop computers in terms of processing power, features and performance. Limitations in display and miniaturization technology prevented laptops from being able to compete with desktops as "real" (i.e. full featured) computers. Recent advances in technology have dramatically improved laptop performance and it is increasingly common to see software development being done on a laptop. Laptops with a 133 MHz Pentium processor, 1.2 Gigabyte hard disk, modular 6x CD ROM drive and 12.1 inch SVGA display are available in mid-1996, albeit at a price premium over comparable desktops. A survey in Computerworld