Public Safety Criticizes Wireless Carriers’ Z-Axis 9-1-1 Indoor Location Proposal
Tuesday, October 02, 2018 | Comments

Public-safety groups took wireless carriers to task in filings with the FCC regarding 9-1-1 location technology, saying a CTIA proposal is “unacceptable” and accusing carriers of trying to dilute the definition of dispatchable location.

CTIA, an association representing U.S. wireless carriers, said last month in a report that testing supported a Z-axis metric of only ±5 meters for 80 percent of fixes, yet added that the FCC should not adopt any metric at this time.

FCC rules required industry to submit a Z-axis location accuracy metric for consideration based on the test bed by Aug. 3. The Z-axis location could allow a first responder to locate a 9-1-1 caller within a high-rise to the correct building floor and suite, for example.

The Association of Public-Safety Communications Officials (APCO) International said the carriers’ proposal “fails the American public and the dedicated public-safety professionals who need actionable, accurate location information to find 9-1-1 callers during emergencies.”

APCO said the carriers’ Z-axis metric proposal is disconnected from what’s technically feasible and what’s actionable for an emergency response. The association said the FCC should reject the proposed Z-axis metric and obligate the carriers to provide dispatchable location.

“CTIA failed to explain how it arrived at ±5 meters,” APCO said. “The participating technology providers indicated support for a more accurate but readily achievable metric. The test bed results indicate that ±1.8 meters is achievable today, and technologies will no doubt improve between now and the vertical accuracy benchmark in 2021.”

Indeed, the two vendors that participated in the testing, NextNav and Polaris Wireless, filed comments supporting adoption of a metric of at least 3 meters for 80 percent of fixes for E9-1-1 and arguing that their technologies are ready for commercial deployment.

“Accepting the carrier’s proposal would mean that 9-1-1 location accuracy is worse than it otherwise would have been under the commission’s 2014 proposal,” APCO said.

The National Public Safety Telecommunications Council (NPSTC) agreed the CTIA proposal is unacceptable, noting the technology is available and a more stringent metric should be adopted.

NPSTC added that the carriers have adequate resources to roll out the technology. The council pointed to AT&T’s 2017 annual report showing operating revenues of $160.54 billion and a net income of $29.45 billion. The 2017 Verizon annual report shows $126.0 billion in consolidated revenues and $30.1 billion in net income. T-Mobile reported 2017 total revenues of $40.6 billion with a net income of $4.536 billion, with Sprint reporting $24.323 billion in total net operating revenues with a net income of $7.32 billion in 2017.

NPSTC also accused carriers of “attempting to dilute the definition of dispatchable location” included in the FCC’s 2015 fourth report and order. Several of NPSTC’s member organizations also are members of the CTIA 911 Location Accuracy Advisory Group.

“Our member organizations report that the carriers, working with the Alliance for Telecommunications Industry Solutions (ATIS), have produced a standard on location accuracy for emergency calls that includes two different definitions or ‘levels’ of dispatchable location,” NPSTC said. “The ATIS standard includes a ‘DL Level 1’ and a ‘DL Level 2.’ ”

DL Level 2 is described as location information that is enough to locate a wireless caller on the correct floor and in the correct suite, and therefore, closely resembles the commission’s definition. However, DL Level 1 is less accurate and could report a location that is a floor above or a floor below that of the caller, or even a building adjacent to, or across the street from, the building in which the caller is located.

“Therefore, DL Level 1 is not consistent with the definition in the commission’s rules and is unacceptable from a public-safety standpoint,” NPSTC said. “Furthermore, having these two definitions is likely to create confusion. NPSTC therefore urges the commission to maintain its current definition of dispatchable location, regardless of any apparent attempts by carriers to dilute that definition.”

In fact, APCO said adopting the carriers’ proposal would likely result in the abandonment of dispatchable location solutions.

“Because carriers have the option to pursue dispatchable location or Z-axis technologies, they would have every incentive to take the easiest path,” APCO said. “A Z-axis metric that’s more conservative than what’s readily achievable today gives the carriers little reason to invest in dispatchable location. Although CTIA requests additional time for testing, public safety is left with no guarantee that the industry will propose a more acceptable metric.”

APCO urged the FCC to make clear that the carriers must comply with its vertical location accuracy requirements by providing dispatchable location. “That is the only way to ensure that public safety remains on track to receive actionable indoor wireless 9-1-1 locations to carry out their life-saving missions,” APCO said.

The International Association of Chiefs of Police (IACP), International Association of Fire Chiefs (IAFC), National Association of State EMS Officials (NASEMSO) and the National Sheriffs’ Association (NSA) filed joint comments agreeing with APCO and NPSTC.

“The recent Stage Z test bed confirms that a location fix better than a 3-meter altitude determination is already achievable today, even though the FCC’s rules do not require wireless carriers to implement such a solution until 2021,” the groups said. “The FCC also should not delay adoption of a same-floor accuracy metric while still further testing is conducted.”

The public-safety groups said in a session held in July 2018 in Washington, D.C, First Responder Network Authority (FirstNet) AT&T announced it has agreed to provide floor-level accuracy for first responder tracking and situational awareness with a target of meeting this goal by June 2019.

AT&T did not submit comments in the filing. AT&T is a member of CTIA. Other than CTIA, Verizon was the only carrier to submit separate comments. Verizon said wireless providers are committed to using dispatchable location as their principal method to deliver the vertical location information of wireless 9-1-1 calls.

“Verizon believes it is premature to adopt ±5 meters as the Z-axis standard at this time,” the mobile provider said. “Rather, it would be better to step up efforts to advance location solutions that pave a path to the ultimate goal of ‘floor level’ accuracy. That includes efforts to advance the implementation of the National Emergency Address Database (NEAD) and to conduct further testing on alternative Z-axis solutions that would improve on Z-axis accuracy. Verizon believes the wireless industry is committed to taking those steps and is hopeful that the vendors who did participate in the test bed will do so again more comprehensively, and that additional vendors will participate as well.”

The Boulder (Colorado) Regional Emergency Telephone Service and the Florida Department of Management Services Bureau of Public Safety also submitted comments in favor of public safety’s suggested Z-axis location metrics. All the filings are here.

Would you like to comment on this story? Find our comments system below.

Post a comment
Name: *
Email: *
Title: *
Comment: *


No Comments Submitted Yet

Be the first by using the form above to submit a comment!


March 2023

27 - 30
International Wireless Communications Expo (IWCE) 2023
Las Vegas

May 2023

23 - 25
Critical Communications World (CCW)
Helsinki, Finland

More Events >
White Papers
More White Papers >

Site Navigation