We love our smart phones. Except when they run out of batteries. And we find ourselves cruelly cut off from the wireless world. But new research is extending our coveted smart phone time, by putting the phone almost to sleep.

Right now, even when your phone is in power save mode, it's still expending a lot of energy listening for incoming information, like calls or text messages. So researchers at the University of Michigan came up with a new technology that could reduce most smart phones' energy consumption by about 44 percent. They presented their findings at the ACM International Conference on Mobile Computing and Networking in Las Vegas. [Xinyu Zhang and Kang G. Shin, "E-MiLi: Energy-Minimizing Idle Listening in Wireless Networks"]

This new power saving mode saves juice by slowing down the phone's wi-fi frequency. That idea’s been around, but the trouble has been making sure the slow phone can still access incoming information. New messages usually come in two parts: a title and a main body. This new mode has the phone listen only for titles. When one arrives, the phone wakes up to receive the rest of the message. Otherwise, it's waiting, mostly asleep—and saving that precious battery life just for you.

—Rose Eveleth

[The above text is a transcript of this podcast.]