Email Print Share

"Power Nap" -- The Discovery Files

The Discovery Files
Audio Play Audio
The Discovery Files podcast is available through iTunes or you can add the RSS feed to your podcast receiver. You can also access the series via AudioNow® by calling 641-552-8180 on any telephone.

A new "subconscious mode" for smartphones and other WiFi-enabled mobile devices could extend battery life by as much as 54 percent for users on the busiest networks.

Credit: NSF/Karson Productions

Audio Transcript:

(Sound effect: Smart phone ring) A Smarter Smart Phone.

(Sound effect: theme music) I'm Bob Karson with the discovery files--new advances in science and engineering from the National Science Foundation.

When your smart phone is waiting for your next hookup, it's on alert looking for messages and searching for clear communication channels. Did you know that it could be using as much power then as when it's sending and receiving messages? Researchers at the University of Michigan are working to make that idle time a lot less of a drain.

Meet "E-MILI," which stands for "Energy Minimizing Idle Listening." A way to have smart phones go into a slower, deeper mode of sleep, but still be ready to jump to full power when needed. The team believes that by using this new technology most smart phones could still keep one eye open for incoming messages while using as much as 44% less power.

E-MILI slows the clock in your Wi-Fi card to one-sixteenth of its normal frequency, that's easy, the hard part is to get the phone to recognize incoming messages while almost in a coma, so it can jolt back to full speed. Their solution was to get it to recognize just the headers of incoming messages. So they found a new way to encode the address header.

To do this, it's going to require firmware modifications by the Wi-Fi chipset manufacturers, as well as getting the makers of smart phones onboard to install the chips in new phones. The project is in the proof-of-concept stage and could be reality soon.

Smart phones taking a real "power nap" -- would that make them "sleeper cells?"

"The discovery files" covers projects funded by the government's national science foundation. Federally sponsored research--brought to you, by you! Learn more at or on our podcast.

General Restrictions:
Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation. Additional information about general usage can be found in Conditions.

MP3 icon
NSF podcasts are in mp3 format for easy download to desktop and laptops, as well as mobile devices capable of playing them.