Current mobile devices embrace a wide range of functionalities including high speed network support, hardware accelerated 3D graphics, and multimedia capabilities. These capabilities have boosted the interest for enabling multiplayer online games (MOG) support on such devices. However, the lack of similar growth in battery technology limits the usability of these devices for MOGs. In this paper, we present energy conservation techniques for highly interactive MOGs. These are games, such as firstperson shooters, where crisp user interaction is paramount to the overall game experience. Hence, conserving energy while preserving crisp user interaction becomes a critical consideration in this domain. We first present three obvious power management approaches and highlight their limitations. We then discuss two applicationassisted approaches for power management that manage to save power while preserving the required user experience. Our results demonstrate that these applicationassisted approaches are very promising.
Categories and Subject Descriptors
General TermsAlgorithms, Management, Measurement, Performance, Design, Reliability, Experimentation, Human Factors.
KeywordsMobile games, wireless networks, power management, statistical prediction.
INTRODUCTIONThe number of personal portable devices sold each year is increasing rapidly with mobile phone sales outpacing personal computer sales at the rate of 5 to 1 7. Current mobile phones are not just devices for voice communication, but are mini computers that have high speed wired and wireless networks, and sufficient processing and memory capabilities to run enterprise, multimedia, and gaming applications. However, the user experience obtained from running multimedia streaming and highly interactive applications on mobile phones is usually much lower when compared to running those same applications on a desktop computer. Beside several user interface factors, there are several technical factors that hinder the user experience for multimedia streaming and interactive applications on mobile phones. One of the key challenges is battery lifetime. For example, a mobile phone's battery may only be able to support 4 to 6 hours of actual voice communications and about 2 to 4 hours of streaming video. This perilous energy situation becomes even worse when the 802.11b or g network interface of the mobile phone is activated. 802.11b/g has higher energy usage compared to GSM based networks as the Carrier Sense function of 802.11b/g's CSMA/CA protocol consumes energy continuously. As various studies have shown 77, the wireless interface and CPU are the major power consuming components in mobile devices the wireless interface alone can consume up to 50% of the total system power.In this paper we first present three obvious power management approaches and demonstrate their limitations. We then present two approaches based on predicting a game player's behavior. In these approaches, we first use a simple linear prediction algorithm to decide the player's activity level and ...
