FCC moves to improve location accuracy of 911 callers in multi-story buildings

Next month the Federal Communications Commission (FCC) will vote on new rules meant to help first responders more accurately determine which floor a 911 call originates from in multi-story buildings.

FCC Chairman Ajit Pai on Tuesday circulated a draft order (PDF) that would require wireless carriers to provide vertical (or z-axis) location data that’s accurate within 3 meters (approximately 10 feet) of the caller’s handset for 80% of indoor 911 calls.  

The proposal sets a deployment deadline of April 3, 2021 for wireless carriers to roll out z-axis technology in the top 25 U.S markets, expanding to the top 50 markets by April 2023.

It also calls for testing by operators to validate that their z-axis technology meets accuracy metrics, and extends privacy protections to the vertical location data shared from 911 calls.

In a blog post, Pai said that today’s system does a good job of providing the street address for 911 calls made from cellphones, but that doesn’t extend to vertical location data.

“That can be a big problem if you are calling 911 from a high-rise building like an office tower, and a delay of minutes in first responders finding you can be the difference between life and death,” wrote Pai. “After years of study and testing, the Commission will vote in three weeks on adopting a vertical location accuracy metric of plus-or-minus three meters. This metric is supported by a broad-cross section of public safety organizations because it would more accurately identify a 911 caller’s floor level and is achievable.”

First responders, including the International Association of Fire Fighters, the International Association of Fire Chiefs, International Association of Chiefs of Police, National Sheriffs’ Association, and National Association of State EMS Officials, have all voiced support for the 3-meter metric.

The commission decided to advance the rules and 3-meter requirement in March and sought public comment after tentatively concluding the metric was enough to identify a caller’s floor level most of the time.

Originally, CTIA, on behalf of the nation’s four largest carriers, proposed a 5-meter requirement over questions about technology performance and scalability. Some public safety commenters wanted even more accurate location data, but the FCC decided that a stricter 2-meter benchmark was not yet technically achievable though it could be later down the line.

In March, Commissioners Jessica Rosenworcel and Geoffrey Starks each felt the roughly 10-foot margin of error still needed to be improved as it could send first responders to the floor above or below a 911 caller. Starks had called for a clear plan to get to a greater level of accuracy than 3 meters.

“Only floor level accuracy will give first responders the right tools to go to the right floor, the first time, every time,” said Starks in his statement (PDF) at the time. “We need a plan to get there and that plan has to get it done as quickly as possible.”

In a September letter (PDF) urging Rosenworcel to support setting the z-axis metric for 911 calls at 3 meters, the International Association of Fire Fighters noted that recent filings by wireless carriers suggested “a troubling effort to delay long-agreed milestones and to weaken metrics,” specifically related to the vertical location requirements.

“Three (3) meters is achievable now, can easily be implemented, will significantly speed response and most importantly, will save lives,” the group wrote.

The commission plans to consider tightening the location data accuracy requirement further at its  Nov. 19 open meeting where it will vote to seek comment on whether to implement a stricter z-axis metric over time and ultimately require wireless carriers to report the caller’s specific floor level.

The Further Notice of Proposed Rulemaking would also seek public comment on alternative deployment milestones for z-axis and dispatchable location technologies.