Can your wearable’s sucky battery life be saved? Maybe by streaming to a smartphone
Microsoft Research believes the key is to avoid writing data to and from flash memory.
By Mark Hachman
PCWorldJul 10, 2015 10:10 am PDT
Is there any wearable user who’s not completely happy with his or her battery life? Yes? Aaah! Stop shouting! You’ll be happy to hear that Microsoft Research believes they’ve found a possible solution.
According to a paper that Microsoft Research employees Ranveer Chandra and Anirudh Badam will present at the USENIX Technical Conference this week, eliminating the need to read and write data to a wearable’s onboard flash memory can significantly improve battery life in a wearable like a smartwatch.
In the paper, Microsoft claims that its WearDrive system allows applications run at 8.85X better performance and consume up to 3.69X less energy than traditional methods.
The research comes at a time when many are wondering whether the wearable market is languishing in a pool of apathy—in part because more sophisticated smartwatches chew through battery life quickly. Fitness trackers like the Fitbit have battery life measured in days, but the Apple Watch can expire by early evening. All this requires a solution to get the wearable market back on track.
That sounds simple enough, but what should a smartwatch do with the data, then? The answer, the researchers say, is to stream it to a phone via a Bluetooth or Wi-Fi connection. Of course, that requires a phone to be within wireless range at all times, or frequently enough that the data stored in the bits of a smartwatch’s memory can be relayed to a phone before it needs to be written in flash memory. The key is to stream the data to the phone via Bluetooth Low Energy (which consumes just 1 to 2 milliwatts) as opposed to using flash memory and the related storage software to write it to the phone, the authors say. And if it does store data on the phone, WearDrive uses only DRAM to store data until the phone comes back in range.
DRAM, of course, is volatile—the data it contains vanishes if the memory chip loses power. But the odds of that happening are extremely low, the authors say—if the wearable is running low on power or is going to be shut off, the data in RAM can be written to flash memory in time. And since a wearable’s battery isn’t removeable, an unexpected loss of power should rarely occur.
“Everyone has been thinking of reusing what exists for mobile devices,” Chandra said, according to a Microsoft research publication, referred to via Neowin. “What we’re saying is, ‘It’s a different paradigm. It’s a different usage scenario.’”
A member of the Microsoft Band team says there are no plans as yet to implement the technology in its own wearable. (Microsoft’s Band is somewhat infrequently updated, anyway.) In any event, Microsoft tested WearDrive against Android, and the Google WearSDK.
Why this matters: It’s not clear how much overall power was saved in either the smartphone or wearable, although the paper breaks down the power savings by application—passive heart-rate monitoring, for example, was between 39 percent and 54 percent more efficient, and batching up notifications and sending them over all at once can save a whopping 149 percent. Still, with consumers beginning to wonder why they’ve spent $200 to avoid taking out their phones, the wearables market needs improvements like this to keep the faith.
Updated at 10:09 AM on July 10 with more details from the paper.