Flat mobile battery? Blame the ads, says study

In-app ads are seen by some as a waste of space on small screens, but what those ads are really wasting is your battery life, according to new research conducted by researchers at University of California, Berkeley, and Microsoft.

by Helen Leggatt

Flat battery on your mobile device? Blame the ads. According to new research conducted by Microsoft, receiving and displaying in-app ads on a mobile device is draining your battery.

Ads in popular Windows Phone apps chew through, on average, 65% of an app's total communication energy, or 23% of the app's total energy, found the research.

Till Faida, co-founder and managing director of Adblock Plus (software that has been removed from Google Play!), says consumers are blaming their mobile device for poor battery performance when, in fact, it's the ads that are to blame.

"The use of in-app advertising has enabled an ecosystem of free apps for many people's enjoyment, but we have to consider the impact this is having on battery drain," said Faida.

The study authors, Prashanth Mohan, U.C. Berkeley graduate student, Suman Nath, senior researcher at Microsoft Research, and Oriana Riva, researcher at Microsoft Research, found that in-app ads are typically refreshed every 12 to 120 seconds, forcing the radio network to be continually re-activated. However, after an app's ad download is complete, the app keeps its 3G radio connection open for a further 25 seconds. It is this period, dubbed "tail time", that results in an ad's "high-energy overhead".

The research paper investigates a process called "prefetching" which can help reduce this high-energy overhead.

"Intuitively, prefetching can amortize the tail energy cost among multiple ads," explains the paper. "Our experiments show that downloading 10 ads of size 1 kB (or 5 kB) in bulk over AT&T 3G network consumes 8.6x (or 4.1x respectively) less energy than downloading them one every minute. Moreover, prefetching enables downloading ads at opportune times, such as when the phone is being charged or Wi-Fi connectivity is available. Finally, unlike solutions that require changes at the networking stack, a prefetching-based solution can be deployed on today's smartphones with minimal changes to existing ad infrastructures."

Image via Shutterstock

Tags: battery, in-app ads, mobile advertising, mobile apps, research, smartphone, tablet