The US Moves Wireless 911 Requirements Indoors

Adrian Stimpson Industry Views, Points of Interest

About the Author

Adrian Stimpson

Adrian is the Senior Vice-President of Sales and Marketing at Rx Networks.

The proliferation of GNSS equipped mobile phones has had a profound effect on society’s ability to respond to emergencies. The days of running to the nearest house or payphone to call 911 are now just a historical footnote.  In fact, 80% of 911 calls are now made from mobile phones.

Rx Networks is a major player in the wireless 911 market, supplying the GNSS assistance data used by all Canadian, and the majority of US, mobile subscribers.

The service has saved countless lives, however, the ability to determine the exact location of a caller who is indoors, outside the reach of normal GNSS coverage, has been a problem the companies like Rx Networks have been working hard to address.  Given that 64% of mobile calls are made from indoors, and many are from within multi-story buildings, there is a need to determine not just the building address (using an x, y coordinate), but also the floor the caller is on (altitude/z-axis).

Given the work that Rx Networks and other companies have done in recent years, the US Federal Communications Commission (FCC) recently asked companies to comment on proposed rules for mobile operators that would require them to accurately determine a wireless 911 caller’s location, even if indoors. The end goal is a “dispatchable address” where first responders know exactly where to go – address and floor.

Rx Networks provided a response to this request for comments (available at, highlighting some of the ways we could help mobile operators meet a potential mandate.

With much input from industry and other stakeholders, including first responders and the general public, the FCC adopted new rules on January 29, 2015, that set out the following timelines and accuracy requirements for the national mobile network operators (regional operators have slightly extended deadlines):

Either a dispatchable location or x, y accuracy of 50 meters or better must be achieved as follows:

  • Within 2 years, 40% of the time
  • Within 3 years, 50% of the time
  • Within 5 years, 70% of the time
  • Within 6 years, 80% of the time