Power Management
Latest devices are equipped with large color displays, multi-megapixel cameras, various radio transmitters, advanced multimedia, and other fancy features – all of which consume a lot of power. At the same time, more power-hungry applications that utilize the new
possibilities are provided.
Power optimization has become crucial to keep the device power consumption on an acceptable level and to prevent users running out of battery.
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Top 10 Energy Saving Tips
Read at least these or refresh your memory of the key actions.
S60 Platform: Effective Power and Resource Management
Learn how to reduce power and resource consumption in C++ applications without sacrificing their application performance.
Recommendations for Reducing Power Consumption of Always-on Applications
Learn how to optimize power consumption of always-on applications such as Push e-mail and instant messaging.
Why should you care?
A mobile device quickly running out of battery when using an application, or multiple applications, would lead to disappointed customers and thereby to decreasing sales. This would also dilute the whole mobile application market. Users don't want, and may not even have the possibility, to constantly recharge their devices. On the other hand, power-efficient applications typically also perform well, that is, optimized code runs faster. Usually this applies to resources as well - low resource usage contributes to low power consumption, and vice versa. Besides this, there are the ethical, environmental, and economical aspects to consider - from the user’s perspective. Lower power consumption means lower total energy usage, which may not be that a significant issue in the mobile device scope; however, every stream counts.
Overview
Power management and consumption has become an issue of increasing importance. Battery capacity, combined with the pressure to reduce the physical size of the battery, is not keeping up with the increased power consumption of new mobile multimedia computers. There is no simple, straightforward solution to this problem, but power consumption must be considered on all fronts, and with many small actions. Device and hardware vendors and network operators need to work actively on it, and software developers need to optimize their applications.
Optimized power consumption is an important aspect of application quality!
The exact means to reduce power consumption depend on the characteristics and functionality of the application in question, but certain hypotheses remain the same. For example, understanding where, when, and why most power is consumed is a key to understanding what to optimize and where to place the most effort on.
The less you process, the less energy is consumed!
And what comes to battery lifetime, the average power consumption is usually more important than transient power peaks. Furthermore, in general, efficient code and freeing resources that are not in active use consumes less energy compared to, for example, a fancy UI with top quality content. Some balance is always needed, and often fancy UIs are truly important. On the other hand, certain applications, such as maps and navigation applications and always-on applications, consume a lot of energy by default. However, there are also power-efficient means to implement those applications, without sacrificing usability and user experience.
What should operators and network administrators do?
Open data connections and data transfer over the network consume a lot of power. This is a major issue for all applications that utilize network connections, but an even more crucial issue for always-on applications. This is something that network operators and administrators can affect with their configurations. For more detailed information, see Recommendations for Reducing Power Consumption of Always-on Applications
