Too good to be true?
That's what I thought when Signal Pro Bill Van sent me a link to the Hive Mind Blog
article that claims that you'll get better battery life using 802.11ac networking. It's a big deal, because phones like the new HTC One are shipping with the new wireless technology now, and we're all hoping that it won't be another fiasco like when Sprint's phones started featuring 4G technology that drained batteries in under 30 minutes.
The argument is simple, actually: By stripping down its 802.11ac support to the simplest possible protocol, you can actually use less power than 802.11n chipsets that support multiple options and multiple configurations.
To this I have to say... horse hockey.
Saying that you'll use less power using a stripped-down chipset is kind of like saying you'll use less gas in a Ferrari than in a Prius if you get rid of 10 of the 12 spark plugs. OK, that may be a little extreme. You'll still get most of that 802.11ac goodness, especially since 802.11ac isn't even really an established standard yet so none of the real fancy bits are guaranteed to be compatible with anybody else's fancy bits. So in that sense, considering that you'll be running your 802.11ac device in the simplest, most compatible way possible, you'll use less power by not even trying to make things difficult.
Surely there are low-power 802.11ac chipsets right around the corner, and by the time the standard is actually ratified, they'll probably be ready. No guarantee that they will be less power-hungry than today's low-power 802.11n chipsets, but assuming that you're actually consuming data at the same rate (meaning the 10megabit range that seems to be the real-world top speed for smartphone data right now) I'll go so far as to say that it's possible that you won't use any more
power than you would with the 802.11n chips.
There's another possibility, and it also falls under the category of "if absolutely everything goes perfectly." Technically, faster 802.11ac chips with proper power management could fetch data faster than 802.11n chips, then go back into power saving mode while waiting for more data to become available. Techniques like this have been demonstrated as a way to reduce congestion -- the WiFox technology
looks good in theory but isn't actually used anywhere yet. Last week at Mobile World Congress, Broadcom showed a prototype
of this technology that controls LTE service. If it works, it could be adapted to 802.11ac.
The simple truth is that there hasn't been, and doesn't look to be, a magic potion that will let you expend 10 times as much power doing anything, and use a battery 1/10th the size. It could happen someday, but until then, look out for anyone who says that they can promise you more power for less battery.