Researchers detail way to double battery life of Wi-Fi devices

Duke University grad student Justin Manweiler and a team of researchers have developed a way to significantly increase the battery life of Wi-Fi devices without changing the device itself.

The technique essentially regulates how long and when the device's radio sleeps so that data transfers are scheduled more efficiently.

Duke researchers tested eight laptops and nine Nexus One Android-based smartphones on an 802.11n network. By using the scheduling technique, called SleepWell, they were able to show energy reductions of 38 percent to 51 percent across a variety of online applications, including YouTube, Pandora and TCP bulk data transfers.

"In light of these results, we believe that SleepWell may be an effective solution for the future, not only to sustain a demanding suite of [mobile] applications, but also to improve ‘immunity' to increasingly dense Wi-Fi environments," the researchers conclude, in a paper presented at the annual MobiSys Conference in Washington, D.C.

In essence, SleepWell technology brings in a type of distributed time division multiple access (TDMA) technique to a Wi-Fi network so that several users can share the same frequency channel based on different time slots. The technology gives Wi-Fi access points the ability to regulate how long Wi-Fi clients sleep and coordinate with nearby APs.

"The solution is analogous to the common wisdom of [commuters] going late to the office and coming back late, thereby avoiding the rush hours," the authors wrote.

For more:
- see this Network World article

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