Feeds

Boffins boost battery life with underclocked Wi-Fi

Removing the idle listening energy tax

Boost IT visibility and business value

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. ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
Déjà vu: Virgin Media jacks up broadband prices
Screw copper phone lines, we're UNIQUE, bleats telco
UK fuzz want PINCODES on ALL mobile phones
Met Police calls for mandatory passwords on all new mobes
Netflix swallows yet another bitter pill, inks peering deal with TWC
Net neutrality crusader once again pays up for priority access
Fifteen zero days found in hacker router comp romp
Four routers rooted in SOHOpelessly Broken challenge
EE: STILL Blighty's best mobe network, says 'Frappucino' Moore
Fresh round of network stats fisticuffs possibly on the cards here
New Sprint CEO says he will lower axe on staff – but prices come first
'Very disruptive' new rates to be revealed next week
US TV stations bowl sueball directly at FCC's spectrum mega-sale
Broadcasters upset about coverage and cost as they shift up and down the dials
Canadian ISP Shaw falls over with 'routing' sickness
How sure are you of cloud computing now?
UK mobile coverage is BETTER than EVER, networks tell Ofcom
Regulator swallows this line and parrots it back out at us. What are they playing at?
What's the nature of your emergency, Vodafone?
Oh, you've dialled the wrong number for ad fibs, rules ASA
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.