Justin Manweiler, a computer science graduate student at Duke University's Pratt School of Engineering, claims to have found a way to dramatically improve battery life of mobile devices with a small alteration to Wi-Fi technology. The proposed solution is called SleepWell and works by allowing devices to take short 'naps' while waiting to transfer data.
As Scientific American explains, mobile devices waste a lot of energy searching for a Wi-Fi signal and then staying connected while overtaxed wireless networks ferry data to and from them. This gets even worse when there are many devices vying for the same wireless signal. Manweiler uses an analogy to describe the current process:
"When workers leave their offices en masse at the end of the day, they clog up the roads and rail lines. If these workers staggered the times they left, the transit systems would be less crowded, and it would take less time to get home," the report reads. "Similarly, if mobile devices took their turn accessing WiFi access points, data would move faster and these devices would use less energy."
Manweiler's software embraces this idea by detecting when several Wi-Fi devices that are actively using the network and puts their Wi-Fi radio in sleep mode while they're waiting for data. The sleep periods are so short that the user remains unaware and unaffected – apparently they happen many times a second. And since SleepWell is intended to run on access points (like routers), your smartphone and laptop could benefit from it without having to do anything at all.
The extent to which battery life would be prolonged varies depending on the situation. However, during testing, Manweiler found that SleepWell could double the battery life of mobile phones. We assume it will be most noticeable in crowded public hotspots, though it's also worth noting that Wi-Fi is not the only battery drain you have on a phone.