Over the years WiFi has been an amazing technological advance! Being able to wirelessly connect our laptops and PDAs to traditional networks, whether at home, the office, or at school was significantly helpful not only for those using the networks, but also for those of us in IT departments who didn’t have to pull as many new ethernet cables. As our phones became more capable, WiFi became more important – and just as well received – if not moreso!
WiFi works by sending and receiving a microwave radio signal through the air to a Wireless Access Point. Radio waves are essentially electricity from your battery that has been converted into a specific frequency, and pushed out of your device through an antenna. As you can imagine, that can drain your battery fairly quickly.
When calculating battery drain there are a lot of variables that one must consider, such as distance from the WAP, signal strength, radio noise in the area, and how much data is being sent and received. To help conserve power, many people opt to simply leave WiFi “off”. However, that may have some unintended consequences, and these days, off isn’t really “off”.
Using WiFi rather than cellular for data access can yield a significant savings when it comes to battery life – depending on the circumstances. The further you are from a cellular tower, the more energy you need for that data signal to be of any use. WiFi access points are typically much closer than cell towers, and can therefore use less power to communicate data than cellular.
Of course there are exceptions to this rule, and the observed reality may be significantly different in one situation versus another.
These days we like our phones and tablets to know right where we are. They help us get from point A to point B, and geotag our pictures so we know where we took them years down the road. They also enable our devices to do some pretty snazzy things based on where we are, when we enter an area, or when we leave an area. This concept is called geo-fencing.
Like a regular fences, geo-fences encircle an area. With this virtual “fence” in place, your device can trigger certain events like unlocking your doors, turning on your lights, setting your thermostat, and automatically sending a Tweet that you’re home and ready for game time!
The service called IFTTT (If This Then That) is a perfect example of what you can do: if you leave or enter an area, then do something cool. I’ve even got my Nexus 5 configured so it knows when I’m at church and automatically sets my phone to vibrate rather than ring.
What does geolocation have to do with WiFi? Geolocation is fairly complex, and when using various satellite services to calculate your location, it can be fairly battery intensive. To combat this, manufacturers have turned to cell towers and WiFi access points to help get a rough location without having to listen for all those satellites.
Ideally, you’d set your WiFi to be off all the time, but turn it on when you crossed a geofence into an area that has a WAP that you regularly connect to, and turn it off again when you exit that geo-fenced area. The Xperia Z has a feature called “Location-based Wi-Fi” that does just that.
Pocketnow’s Anton D. Nagy loves this feature, and who can blame him? His WiFi stays turned off when he’s away from his saved networks, and turns back on when he’s within range.
Ironically, one of the best ways to get your location is through identification of the Wireless Access Points around you, but to do so, your WiFi has to be turned on. Luckily, Google has a little trick it built into our smartphones and tablets. Every once in a while your smartphone or tablet will turn WiFi on to “take a peek” at what’s around it. The battery impact is low, but sometimes has unintended consequences.
Using this information to intelligently turn your WiFi on and off depending on your location isn’t a feature that’s built in to the Android OS, not yet anyway. To use it, either the company that built your phone has to add that functionality or you have to install and configure a third-party app.
In the meantime, if you don’t have location-based WiFi capabilities on your device, ask yourself one question: do you spend more time connected to WiFi networks than cellular? If so, leave your WiFi turned on. If not, it might be advantageous to keep it turned off and save your battery.