This is Scientific American's 60-Second Tech. I'm Larry Greenemeier. Got a minute?
Touch your smartphone screen and you local weather or a street map.
So you might assume that mobile phones know exactly where you are.
But get into trouble and you might find your phone isn't watching you as closely as you thought.
Emergency responders recently told the Wall Street Journal that their 911 dispatchers have trouble getting help to the location of cell phone callers.
And a report this summer showed more than half of all California wireless 911 calls in certain areas didn't have location information.
One way to locate a cell phone is through GPS, assuming the phone has one and it's outdoors.
Another is through location-based services.
These follow the signals sent between your phone and your wireless network's radio towers.
But towers can be miles apart, making it hard to pinpoint locations and adding minutes to response times.
Responders want wireless companies to include location data with each call, something privacy advocates oppose.
It's a matter of perspective.
Sometimes you want to be off the grid.
But in a crisis, the grid could be your best friend.
Thanks for the minute, for Scientific American 60-Second Tech. I'm Larry Greenemeier.