One of the best ways to improve battery life on a laptop, smartphone, or tablet is to shut off the WiFi radio. Of course, that’s not always practical, but a grad student at Duke University has come up with a technique for managing WiFi networking that uses between 38 and 51 percent less energy. When implemented properly, the technique can double the battery life of some devices in some situations.
Here’s how it works. When you’re trying to use a wireless device in a location crowded with a number of WiFi access points, your little WiFi radio works harder and consumes more power. That’s because it has to stay awake indefinitely while waiting for a chance to send data to an access point over the same wireless spectrum as other devices.
Duke University’s Justin Manweiler and Romit Roy Choudhury have released a paper (PDF link) explaining a new system called SleepWell that allows a WiFi radio to sleep while it’s waiting for its turn.
The researchers ran a test on 8 laptop sand 9 Android phones while streaming audio and video files and sending data over FTP, and managed cut power consumption in half. While some sites are reporting that this technique could therefore double your phone or tablet’s battery life, I’m pretty sure that would only be true if your WiFi radio were the only thing using energy on your device. There are still screens, processors, and other components to deal with. But it looks like SleepWell could definitely help improve battery life on mobile wireless devices if widely implemented.