Feeds

Boffins boost battery life with underclocked Wi-Fi

Removing the idle listening energy tax

High performance access to file storage

Scientists from the University of Michigan have devised a power management system that can greatly improve the lifespan of radio devices such as smartphones and laptops.

Engineering professor Kang Shin and doctoral student Xinyu Zhang have developed a technique for saving the battery life of Wi-Fi devices by clocking down the Wi-Fi radio system to 1/16th of its normal idling power output.

Dubbed "Energy-Minimizing Idle Listening" (E-MiLi), the technology works with current Wi-Fi technology (when the correct software is installed), and it can extend the life of a battery by up to 54 per cent, according to the boffins.

“We have a proof-of-concept implementation of E-MiLi based on software radios,” Xinyu Zhang tells The Register in an email exchange. In testing, the technique can boost smartphone battery life by 54 per cent.

Even in idle mode, standard Wi-Fi systems use more than two-thirds of the power consumed when fully operational, because the radio needs to be able to accept new data by examining incoming messages. The researchers call this "idle listening". E-MiLi allows the radio to largely power down, but it can reactivate by investigating header information on new data rather than examining all the data as a lump.

Specific tags in the header are needed and to make it work in existing kit, firmware and device drivers must be updated for the Wi-Fi card embedded in those mobile devices. The Wi-Fi cards also need to support downclocking at the hardware level.

"We came up with a clever idea," Shin says. "Usually, messages come with a header, and we thought the phone could be enabled to detect this, as you can recognize that someone is calling your name even if you're 90 per cent asleep."

Shin and Zhang present their paper on September 21 at the ACM International Conference on Mobile Computing and Networking in Las Vegas. They are now working on other power-saving techniques for Wi-Fi, specifically looking at regulating voltage directly.

“We have not completed experiments with voltage scaling. We expect much higher gain, because the power consumption is proportional to clock rate, and proportional to the square of voltage,” Xinyu Zhang says. ®

High performance access to file storage

More from The Register

next story
A black box for your SUITCASE: Now your lost luggage can phone home – quite literally
Breakfast in London, lunch in NYC, and your clothes in Peru
Broadband Secretary of SHEEP sensationally quits Cabinet
Maria Miller finally resigns over expenses row
Skype pimps pro-level broadcast service
Playing Cat and Mouse with the media
Beat it, freetards! Dyn to shut down no-cost dynamic DNS next month
... but don't worry, charter members, you're still in 'for life'
Like Google, Comcast might roll its own mobile voice network
Says anything's possible if regulators approve merger with Time Warner
EE dismisses DATA-BURNING glitch with Orange Mail app
Bug quietly slurps PAYG credit - yet EE denies it exists
Turnbull leaves Australia's broadband blackspots in the dark
New Statement of Expectations to NBN Co offers get-out clauses for blackspot builds
Facebook claims 100 MEEELLION active users in India
Who needs China when you've got the next billion in your sights?
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
HP ArcSight ESM solution helps Finansbank
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.