Commission looks to move CMRS location requirements indoors, expand them from 2-D to 4-D.

Since 2010 the FCC has been insisting on greater accuracy in the ability of wireless providers to pinpoint the location of wireless phones for E911 purposes. The automatic location information (ALI) rules currently in place require that carriers be able to provide Public Safety Answering Points (PSAPs) the location of an E911 caller to within 50 to 300 meters (depending on the technology used). But that requirement applies only to calls originating outdoors, and it mandates provision of only horizontal locations determined by geographic coordinates (i.e., latitude and longitude).

Nowadays, however, wireless phones are the source of most 911 calls, and the “great majority” of wireless calls originate indoors – hence the need for improved indoor E911 location capability.

Fortunately, test bed results and industry input confirm that indoor location technologies have improved considerably, so much so that they are expected to “deliver 50-meter location accuracy for many indoor environments with a high degree of reliability” in the near term. With its Third Further Notice of Proposed Rulemaking (NPRM) the FCC is now looking to ensure that the wireless-dependent public benefits from that capability.

But locating E911 callers inside buildings poses an additional question: how are first responders supposed to find the caller-in-distress when the geographic coordinates identified by the carrier turn out to be the site of a multi-story building?

No problem. The various fancy gadgets that can be built into smartphones include barometric sensors. According to a source cited by the FCC, as of 2013 all of Samsung’s “flagship smartphone models” had such sensors on board, as did a couple of Sony models. Apple was expected to join the club in 2014. Because (a) barometers measure air pressure and (b) air pressure varies according to elevation, such sensors can provide vertical location information (the “z-axis”) to supplement the horizontal (“x-axis” and “y-axis”) information already available.

Given all these considerations, the FCC is now proposing to require CMRS operators to hone their indoor E911 location accuracy accordingly. In particular, CMRS operators would have to:

  • Ÿprovide horizontal location (x- and y-axis) information within 50 meters of the caller for 67% of 911 calls placed from indoor environments within two years of the effective date of adoption of rules, and for 80% of indoor calls within five years.
  • provide vertical location (z-axis) information within three meters of the caller for 67% of indoor 911 calls within three years of the adoption of rules, and for 80% of calls within five years. The FCC chose the three-meter spec because the average floor-height in multi-story buildings is between 3.1-3.9 meters (depending on the type of building). Thus, the three-meter spec proposed by the Commission should permit first responders to narrow the search for the caller to a single floor.
  • meet these indoor requirements at either the county or PSAP geographic level.

And a chronological component would be added to the accuracy determination: CMRS providers would have to generate a location fix (“time to first fix”) in no more than 30 seconds in order for the 911 call to be counted towards compliance with location accuracy requirements. (Short calls of, e.g., 10 seconds or less could be excluded in measuring compliance with accuracy requirements because such call may not provide enough time to get a location fix.)

Indoor location accuracy requirements could be demonstrated through participation in an independently administered test bed program modeled on the indoor test bed administered by the Communications Security, Reliability, and Interoperability Council (CSRIC). Providers could also use alternative means providing the same level of test result reliability.

Along with the more stringent accuracy standards, the Commission is proposing to:

  • standardize the content and the process for delivery of confidence and uncertainty data that is generated by CMRS providers for each wireless 911 call and delivered to PSAPs on request.
  • require CMRS providers to inform PSAPs of the specific location technology or technologies used to generate location information for each 911 call.
  • accelerate the previously established timeframe for replacing the current handset- and network-based accuracy requirements with a unitary requirement.
  • require that CMRS providers periodically report E911 Phase II call tracking information, indicating what percentage of wireless 911 calls include Phase II location information.
  • establish a separate process by which PSAPs or state 911 administrators could raise complaints or concerns regarding the provision of E911 service.
  • require CMRS providers to conduct periodic compliance testing.

The NPRM is chock-full of related questions about which the FCC seeks public comment, including: the benefits of implementing these rules; the costs to carriers, whether a specific waiver process should be implemented for carriers seeking relief from the indoor location accuracy requirements; whether compliance within the proposed timeframes is reasonable; and whether the availability of Phase II information for roamers continues to be a concern, since the evolution of location technology may have reduced differences among carriers that could previously have complicated the location process for roamers. Because of the wide-ranging nature of the FCC’s proposals, all CMRS providers should take the time to review the NPRM carefully to assess its potential impact on their operations.

For this blogger, though, the FCC’s proposal regarding the use of z-axis data to benefit the greater good is probably the most significant use of that information since Capt. Kirk issued the command to move the Enterprise Z-minus ten thousand meters to defeat Khan.

Comments and replies will be set when the NPRM is published in the Federal Register. Check back here for updates.