Here's hoping you'll never need to dial 911. But every day, more than 400,000 people do find themselves in emergency situations. Most of those calls, about 70 percent, come from cellphones. So long as you're outside and in plain view of a GPS satellite, first-responders will know exactly how to find you. But if you're calling from a cellphone indoors? Good luck.

This is a relatively new problem in light of the spread of tiny mobile devices. They're great at estimating your general location, and can get pretty specific under the right conditions, but if you're on the 10th floor of a massive office building, you probably don't want medical personnel wasting precious time looking for you on the third floor.

So government regulators are proposing new requirements on wireless carriers, 911 dispatchers and others that would improve indoor location accuracy. The Federal Communications Commission wants to mandate that within 30 seconds of a call, 911 dispatchers will be able to pinpoint a caller's location to within 50 meters on the correct floor. The FCC hopes that by the end of five years, 80 percent of all wireless 911 calls will benefit from the capability.

The suggestion could go a long way toward importing some of the same standards that already apply to outdoor wireless 911 calls and landline calls. The current lack of standards for indoor calls, said FCC commissioner Jessica Rosenworcel, means many people must "cross your fingers and hope and pray" when they dial 911 on a cellphone.

How would the location tracking work? One option being considered is assisted GPS, which combines GPS location information with data from the cellular network. Another idea is to use a technology called AFLT, which triangulates your position on the basis of your distance from multiple cell towers. Giving that location data to first-responders would definitely help in a crisis.

It also raises potential privacy questions.

"Law-abiding Americans should not have to worry about being tracked by law enforcement or other government entities in non-emergency circumstances," said FCC commissioner Michael O'Rielly in remarks Thursday.

By the FCC's own admission, the five-year target is pretty ambitious. Wireless carriers are pushing back on the grounds that the agency has set an impossible deadline. In a statement, the industry's key trade group, CTIA, called the agency timeline "aspirational target-setting." Republican members of the FCC agreed Thursday, saying it would be unfair to impose obligations that wireless companies and first-responders cannot meet.

"We are dealing with human life," FCC chairman Tom Wheeler shot back. "It's never wrong to overreach on those kinds of goals."