Feeds

Boffins boost battery life with underclocked Wi-Fi

Removing the idle listening energy tax

Designing a Defense for Mobile Applications

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. ®

HP ProLiant Gen8: Integrated lifecycle automation

More from The Register

next story
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
Bigger, harder trouser bulges foretold for fanbois
Bring back error correction, say Danish 'net boffins
We don't need no steenkin' TCP/IP retransmission and the congestion it causes
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
Samsung Z Tizen OS mobe is post-phoned – this time for good?
Russian launch for Sammy's non-droid knocked back
Telstra to KILL 2G network by end of 2016
GSM now stands for Grave-Seeking-Mobile network
Seeking LTE expert to insert small cells into BT customers' places
Is this the first step to a FON-a-like 4G network?
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
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.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.