Emergency call centers sometimes have a hard time pinpointing an address when a person uses a cellphone to dial 911. Sussing out where inside a building a caller is located is even tougher.
The Federal Communications Commission on Friday advanced a new standard that for the first time specifies how precise the in-building, vertical-location data that wireless carriers send to 911 call centers has to be. The agency will now seek public comment.
The regulator said altitude data should be accurate within 3 meters, or 10 feet, of the cellphone caller.
That in effect means dispatchers would receive a location that is accurate to the floor level of where the caller is standing in most cases. The largest margin of error would essentially be one floor above and one below.
The 3-meter standard is both specific enough to help dispatchers and first responders, and feasible enough for nationwide carriers to achieve with new technology by 2021 for 80% of indoor wireless 911 calls, FCC staff said in meeting documents.
Carriers must comply with the standard first in areas with the largest populations of cellphone users.
“Anything further than that might have been too difficult to develop and would have taken a lot longer. Anything greater than that and we thought emergency responders might not have gotten specific enough information,” said Ajit Pai, chairman of the FCC, in an interview.
One commissioner, Jessica Rosenworcel, said the proposed distance wasn’t precise enough, arguing that carriers should be able to locate callers with more specificity and under a tighter deadline.
Cellphone calls account for more than 80% of the 240 million 911 phone calls made annually.
Locating those callers has long been a challenge. In recent years, regulators have taken steps to force carriers and technology companies to pinpoint more precisely the horizontal or street-level location of callers and transmit that data to 911 call centers. They are now increasingly focused on finding ways to determine what floor of a given building a caller is on.
The altitude problem is particularly acute in large cities where problems locating callers in skyscrapers can significantly delay emergency responders. Carriers and public-safety-focused companies are developing technologies that measure barometric pressure on a caller’s smartphone to glean how high above sea level or the ground a smartphone is located.
Some 911 industry executives say determining altitude is a harder problem to solve than finding a caller’s horizontal location in part because there aren’t many use cases today that rely on vertical location information. Horizontal location, by comparison, is used for apps such as Google Maps and Uber.
As recently as late last year there was disagreement between a trade body representing the largest nationwide wireless carriers and public-safety industry groups about what degree of accuracy was feasible for the vertical standard.
CTIA, the association that represents the wireless industry, said at the time the location data should be accurate within five meters of the caller, because more precise information was too hard to consistently obtain. Groups representing 911 operators, however, argued that first responders needed more precise information.
The CTIA changed its stance in December.
“We are encouraged by the FCC’s effort to establish a common goal that we can work towards together with the public-safety community,” said Matt Gerst, vice president, regulatory affairs at CTIA.
Today, there are only a few companies able to deliver that vertical location data including mobile location providers NextNav LLC and Polaris Wireless. Alphabet Inc.’s Google is also experimenting with technology to solve the problem.
Under the FCC’s proposal, carriers will also be allowed to send vertical location data based on information within a new database of verified addresses of Wi-Fi hot spots and beacons that help determine where cellphone callers are.
That database is scheduled to go live by April 2021, when carriers would have to comply with the proposed rule.