Boffins crack smartphone Wi-Fi for greater battery life
Researchers have worked out another method for dramatically boosting a smartphone's battery life, by devising a new "subconscious" mode of operation.
A couple of boffins from the University of Michigan have created a conceptual system called E-MILi, or Energy-Minimalising Idle Listening, that looks at the energy wasted when sleeping phones are checking for incoming messages. According to the team, E-MILi could extend battery life by up to 54 per cent.
Through an extensive trace-based analysis of real Wi-Fi networks, Professor Kang Shin and doctoral student Xinyu Zhang discovered that depending on the amount of traffic traversing the network, devices in power-saving mode spend roughly 60 to 80 per cent of their time in idle listening - looking to see if data is coming in so it can be received immediately.
Previous work has apparently shown that phones in this state, generally consume the same power as when they're fully awake.
However, E-MILi slows down the Wi-Fi card's clock by up to one-sixteenth its normal frequency and only jolts back to full speed when the phone notices incoming information. With the phone running at such low speeds, the hard part is getting it to recognise when a message is on the way, though.
The team therefore proposes that Wi-Fi chipset manufacturers tweak their firmware to encode the message header - the recipient's address - in a new detectable way. With E-MiLi chips onboard, handsets would then be able to detect the information, without staying in the battery-draining idle listening mode.
To get manufacturers of handsets and those of Wi-Fi chipsets to both adopt the new tech, might be a hard ask, especially when there are many other methods of battery saving technology out there to compete with. But the potential is most certainly there.
The new power management approach will be demonstrated on Wednesday, 21 September at the ACM International Conference on Mobile Computing and Networking. ®
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