Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Free apps drain smartphone energy on 'advertising modules'

05.04.2012
Researchers have shown that popular free smartphone apps spend up to 75 percent of their energy tracking the user's geographical location, sending information about the user to advertisers and downloading ads.

"It turns out the free apps aren't really free because they contain the hidden cost of reduced battery life," said Y. Charlie Hu, a Purdue University professor of electrical and computer engineering.

Because smartphone batteries must be small and lightweight, power consumption is a major issue, the researcher said. He has led work to create a new tool called eprof - for energy profiler - to analyze how much energy a smartphone app consumes.

New findings show that 65 percent to 75 percent of the energy used to run free apps is spent for advertising-related functions.

"We performed an in-depth case study, the first of its kind, of six popular smartphone apps, including Angry Birds, Facebook and Android Browser," said Purdue doctoral student Abhinav Pathak.

The free Angry Birds app was shown to consume about 75 percent of its power running "advertisement modules" in the software code and only about 25 percent for actually playing the game. The modules perform marketing functions such as sharing user information and downloading ads.

"We believe it is mainly to provide information about the user's geographical location so the ads can be more targeted or customized to that location," Hu said.

Findings will be detailed in a research paper being presented during the EuroSys 2012 conference on April 10-13 in Bern, Switzerland. The paper, written by Pathak, Hu and Ming Zhang, a researcher at Microsoft Research, also suggests a general approach for improving the energy efficiency of smartphone apps.

An application may contain tens of thousands of lines of code, broken down into many components called subroutines, threads and processes. Eprof maps how much energy comes from each component, representing a new way for researchers to study smartphone energy consumption without using a power meter, an expensive and cumbersome piece of laboratory equipment.

"This is the first tool of its kind ever developed for modern smartphones," Pathak said. "We've seen around 1 million apps written since smartphones emerged roughly five years ago, but there has been no systematic way for the developer to see how much energy the different components consume. Using this tool, you can see what should be changed to improve energy efficiency."

The smartphone power drain is caused by a combination of factors including inefficient programs and software glitches called "energy bugs," Hu said.

"Eprof tells you how much energy is spent where," he said. "This may be due to energy bugs or other reasons."

In one case, a piece of advertising software embedded in a free app failed to turn off its connection to the Internet, a function called a socket, requiring another piece of code to resolve the problem and wasting energy.

Inefficient power usage is most likely to occur in interactive programs, which are prevalent in smartphone apps such as games and applications that heavily use built-in phone gadgets like GPS, the camera, compass and "proximity sensor."

A particular source of power inefficiency is a phenomenon called "tails." In principle, after an application sends information to the Internet, the "networking unit" that allows the phone to connect to the Internet should go to a lower power state within a fraction of a second. However, researchers found that after the advertising-related modules finish using the network, the networking unit continues draining power for about seven seconds.

"The past assumption has been that, whenever you see usage you have power consumption, and when there is no usage there is no power consumption," Hu said. "This does not hold true for smartphones."

The tails are a phenomenon of several smartphone hardware components, including 3G, or third-generation wireless systems, GPS and WiFi, not flaws within the app software itself. However, software developers could sidestep the problem by modifying apps to minimize the effect of tails, Hu said.

"Any time you use the 3G network, there will be a tail after the usage," Hu said. "The ad module in Angry Birds obviously uses 3G for network uploading and downloading, while the game itself did not, which is why we blame the ad module for the tail."

Battery drain in smartphones has emerged as a fundamental problem.

"We've been hearing about major problems lately in power usage," Hu said. "A smartphone battery is generally expected to last a day before recharging, but we're hearing about mysterious instances where the battery runs out in a few hours. Users have been complaining about this on Internet forums."

Findings in the paper suggest a way to improve energy efficiency with a technique that has been shown to reduce the energy consumption of four apps by 20 percent to 65 percent.

The ultimate goal is to develop an "energy debugger" that automatically pinpoints flaws in software and fixes them without the intervention of a human software developer, Hu said.

Eprof mirrors a tool created three decades ago called gprof, which tracks how much time is consumed by software components.

"If a program runs for three hours, gprof tells you how much time is spent on each subroutine," Hu said. "We've taken this to a whole new level with eprof to show how much energy is consumed."

The same researchers first created a model making the new profiler tool possible and presented a paper about the model at last year's EuroSys conference. The model estimates how much power a smartphone is using while an app is running.

Pathak is supported by an Intel Ph.D. fellowship.

Related website:

Y. Charlie Hu:
https://engineering.purdue.edu/ECE/People/profile?resource_id=3351
Abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2012/120404HuSmartphone.html

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Communications Media:

nachricht New cruise ship “Mein Schiff 1” features Fraunhofer 3D sound on board
05.09.2018 | Fraunhofer-Institut für Digitale Medientechnologie IDMT

nachricht Small enclosure, big sound, clear speech
31.08.2018 | Fraunhofer-Institut für Digitale Medientechnologie IDMT

All articles from Communications Media >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Molecular motors run in unison in a metal-organic framework

20.03.2019 | Life Sciences

Active substance from plant slows down aggressive eye cancer

20.03.2019 | Life Sciences

Novel sensor system improves reliability of high-temperature humidity measurements

20.03.2019 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>