Carriers, Public Safety Offer Views on Proposed 9-1-1 Location Accuracy Requirements
Thursday, March 12, 2020 | Comments

Wireless carriers said they are working to meet the FCC’s proposed April 2020 initial compliance deadline for 9-1-1 location accuracy, but the metrics shouldn’t be made more stringent. The carriers also said more emphasis should be placed on handset-based solutions for delivering Z-axis location data.

“In November, Verizon issued a request for proposals (RFP) to vendors soliciting proposed technical solutions for Verizon to employ to meet the ±3-meter standard; we have targeted this quarter for selection of a solution based on critical factors including scalability and integration by handset manufacturers,” Verizon said in its comments.

Verizon proposed nationwide milestones for meeting the ±3-meter metric as an alternative to the current geography-based rule. In addition, Verizon recommended benchmarks for Z-axis capable devices.

Google said handset-based solutions have distinct advantages over solutions that require extensive additional tools. The company said carriers should not only be permitted to deploy Z-axis-capable handsets nationwide to comply with the FCC’s vertical location deployment rules, but also should be encouraged to do so if these solutions prove superior.

“While handset-based solutions might be the predominant solution for 9-1-1 location accuracy in the future, the commission should not foreclose other technological solutions,” said the Industry Council for Emergency Response Technologies (iCERT). “In keeping with a flexible approach, the commission’s rules should continue to accommodate network-based solutions …”

The carriers said further testing is needed, but changes to the testing process proposed by the FCC are not necessary. AT&T said requiring enhanced testing processes is “neither practical nor necessary.” “The commission should give industry latitude to test and develop solutions that will meet the 3-meter Z-axis metric,” AT&T said in its comments.

“Additional testing and assessment of Z-axis solutions will better enable service providers and vendors to gauge when and how expeditiously vendors can bring their solutions to scale, when chipset, handset and OS vendors can incorporate the solution(s) into their products, and when service providers can incorporate new solutions throughout their networks and handset activations,” Verizon said.

T-Mobile USA said ongoing testing “will be critical to illuminate the best path forward, with the first production-ready vertical location solution evaluation in Stage Za of the indoor test bed just concluding now, and Stage Zb testing of additional production-ready solutions scheduled to begin in third quarter 2020.”

CTIA said testing of various first responder scenarios, such as power outages, temperature changes or pressurizing stairwells, would be better addressed by the public-safety community. “It would add significant challenges and costs to an already cumbersome testing process to get permissions from building owners to terminate or present risks to power of in-use buildings for testing purposes,” CTIA said.

In its 2015 order, the FCC adopted rules that support two alternative paths to providing wireless 9-1-1 location information, one based on X, Y and Z coordinates and one based on dispatchable location.

AT&T said another way to facilitate provision of actionable location information to first responders is to permit wireless carriers to rely on means other than National Emergency Address Database (NEAD) reference points for dispatchable location data, although the carrier didn’t offer details on other means.

Last month, wireless carriers abandoned the NEAD, the platform designed to support wireless providers’ provision of dispatchable location information to 9-1-1 centers.

Nonetheless, Verizon said nothing should stop service providers from generating and delivering dispatchable location information to public-safety answering points (PSAPs) when feasible. “Verizon has begun delivering dispatchable location to PSAPs for 9-1-1 calls from certain devices when the information can be determined reliably,” the company’s comments said. “These include certain 9-1-1 calls using voice over Wi-Fi and indoor distributed antenna system (DAS) configurations. And Verizon already plans to incorporate dispatchable location capabilities into 5G home voice products.”

However, T-Mobile said calls for dispatchable location for all wireless calls are neither realistic nor technically feasible. “Put simply, there exists no system today or in the foreseeable future that could deliver on such a mandate,” T-Mobile’s comments said. “Further, considerations beyond feasibility suggest that dispatchable location information would not be appropriate for all calls.”

The International Association of Fire Fighters (IAFF) said it is “unaware of any dispatchable location approach that will continue to function during power outages, when darkness, public confusion and reduced communications options heighten the importance of accurate location information to enable emergency responders to assist the public” and it is skeptical of this particular approach.

T-Mobile encouraged the FCC to reaffirm its support of height above ellipsoid (HAE) for Z-axis estimates, “a metric of practical utility to PSAPs, thus affording appropriate local stakeholders the ability to use that information in the manner that best suits their needs.” The Association of Public-Safety Communications Officials (APCO) International has criticized HAE, calling it a raw technical format for altitude with little to no value for 9-1-1 professionals.

A 9-1-1 dispatcher would receive something similar to “101 Main Street; 76 meters, +/- 3 meters HAE” instead of “101 Main Street, 7th floor” or “101 Main Street, Apt. 702.” APCO said the latter would be more effective for 9-1-1 centers.

The Texas 9-1-1 Alliance, Texas Commission on State Emergency Communications (CSEC) and Municipal Emergency Communication Districts Association filed comments. The Texas 9-1-1 agencies said: “It does not appear that there is an integrated product or tool readily available or scheduled for release before April 2021 that would convert Z-coordinate and Z-uncertainty data into usable information at the PSAP.”

The National Emergency Number Association (NENA) said it is “wary” of a dispatchable location delivered without accompanying confidence and uncertainty. “NENA is optimistic that the table has been set for timely development and deployment of floor-level 9-1-1 location solutions,” its comments said. “We believe that, where an accurate Z-axis estimate is available, floor-level estimates should be capable of being delivered by an originating service provider (OSP) within five years. However, NENA notes that there are no such products in production in the market today, and none have been proposed for testing via the test bed, nor has ATIS (Alliance for Telecommunications Industry Solutions) developed a test methodology for such a service.”

IAFF’s members would find it helpful to have the specific floor and room information for every wireless call in every circumstance, the group said. “The IAFF, however, has monitored the development of location technologies closely and recognizes that floor identity capabilities do not currently exist,” IAFF’s comments said. “This should not, however, stop the commission from continuing to strongly encourage innovation and testing into the options that may become available for achieving floor and room identity information. The commission should also task its expert advisory groups with studying these issues in order to identify any additional steps that can be undertaken by the commission to ensure that consistent and reliable floor and room identity information will become available in the future to support critically needed emergency response services.”

Google said the FCC’s draft rules will likely slow the development of technologies to transmit an accurate floor label directly to the PSAP. “By making elevation mandatory and floor level only optional, the commission effectively ensured that the industry will prioritize work on less-useful elevation technologies over more useful floor-level tools,” Google said in its comments.

In addition to addressing consumer privacy issues, Apple said the commission should require that dispatchable location alternatives provide PSAPs with explicit confidence and uncertainty data along with the caller’s civic location estimate. The FCC should also encourage the development of standards that will convey this data in a more understandable and operationally useful way, Apple’s comments said.

For its part, the International Association of Fire Chiefs (IAFC) urged the FCC to narrow the X, Y location accuracy metric. “While a ± 50-meter horizontal metric may provide enough information for a PSAP to provide a dispatchable address, it can also lead to responders arriving at an incorrect building location,” IAFC said. “In order to fully reap the benefits of a Z-axis location accuracy metric, whether 3 meters or narrower, the horizontal location accuracy metric must be as accurate as is technically feasible.”

IAFC also said the FCC should adopt a ± 3-meter vertical location accuracy metric nationwide by 2025 for all buildings above three stories. “… Responders search the floors above and below the scene of a fire. Therefore, responders would search all floors in a three-story building in the event of a fire but may not search all floors in a four-story building, which is why applying this metric on a nationwide basis for structures above three stories is fitting,” IAFC said.

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On 4/13/21, Paul Chan said:
Dear Sandra
Sorry for some typing slips in the last message. Attached is the corrected version

I strongly believe the current CMRS network approaches including MBS by FirstNav and device based HAE metrics by barometer sensing are not the ultimate tools that solve this essential problem for finding wireless 911 callers indoors. Because

1. It is not reliable as dispatchable location information of floor level is concerned.
2. It is not power fail save.
3. It is not a universal applicable like poor DAS in many buildings and it is only applied to urban areas.

A permanent essential approach will have to be a general fixture or fitting at every single civic address that can sustain power outage handshake with wireless device on 911 call to report its ACTIONABLE LOCATION indoors and support onsite third party personnel ie. warden property manager and fire brigade to retrieve the in- building data of such emergebncy call SOS alert and environmental change including presence and movement of occupants all to work independent of commercial mobile radio networking that may be crippled by local blackout when the current approaches all fail.

A reconfigured lighting device can fulfill this task. And I can prove that by sample testing .

Best Regards

Paul Chan


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