Smartphone battery life could dramatically improve with new invention

September 16, 2011

University of Michigan computer scientists have developed a new “subconscious mode” for smartphones and other WiFi-enabled mobile devices that could extend battery life by as much as 54 percent for users on the busiest networks. It’s called E-MiLi (Energy-Minimizing Idle Listening).

Even when smartphones are in power-saving modes and not actively sending or receiving messages, they are still on alert for incoming information and they’re searching for a clear communication channel. Devices in power-saving modes spend 60 to 80 percent of their time in idle listening, expending roughly the same amount of power as they do when they’re fully awake, the researchers found.

E-MiLi slows down the WiFi card’s clock speed to 1/16 of its normal frequency, but jolts it back to full speed when the phone detects message headers coming in. When used with power-saving mode, the researchers found that E-MiLi is capable of reducing energy consumption by around 44 percent for 92 percent of mobile devices in real-world wireless networks.

Implementing it would not be simple, though. E-MiLi requires new firmware for phones and computers that would be sending messages, WiFi chipset manufacturers would have to adopt these firmware modifications, and then companies that make smartphones and computers would have to incorporate the new chips into their products.