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NENA & CTIA Respond To Unfounded Glonass Concerns, Wireless 9-1-1 Location Accuracy Roadmap
[Note: For background on this, read article titled “Congress alarmed by plans to use Russian system to route 9-1-1 calls” here ]
Statement of NENA: The 9-1-1 Association
The recently-announced Roadmap for Wireless E9-1-1 Location Accuracy improvements is not a "carrier plan.” It is a consensus plan negotiated by the national associations representing the 9-1-1 and field responder radio communities, NENA and APCO, and agreed to by the four national wireless carriers.
The plan does contemplate carrier use of Assisted Global Navigation Satellite Systems ("A-GNSS”) – including both the U.S. NavStar/GPS system and the Russian GLONASS system – as one aspect of a multi-pronged approach to improving wireless E9-1-1 location accuracy.
The consensus plan discusses the GLONASS system as a new component of handset A-GNSS capabilities because it is the only globally-available GNSS, other than NavStar/GPS that is currently operating.
The consensus plan does not restrict carriers’ ability to add or substitute other GNSSs, such as the European Galileo and Chinese BeiDou constellations, as those systems come online over the next 5-7 years. However, neither of these systems is currently available.
Because handset A-GNSS chips can operate with any combination of satellites from any supported constellation, adding GLONASS support to existing GPS capabilities will not provide the Russian Federation with any leverage over U.S. E9‑1‑1 capabilities: Even if the GLONASS system were shut-down completely, handsets in locations with clear views of the sky could still calculate location estimates based solely on measurements of U.S. GPS satellite signals.
Even if Russia attempted to somehow degrade the performance of its satellite network, both carrier networks and consumer handsets would be capable of detecting erroneous signals and rejecting them from a position fix.
The consensus Roadmap makes available the full panoply of rapidly-advancing commercial location technologies for E9-1-1 use for the first time. In the event of a GLONASS failure or shut-down, other high-accuracy handset and network-based technologies – including the ability to return the exact address (including apartment, suite, or floor number) of the caller’s location – will still be available.
It’s true that an NDAA amendment places limits on the proposed construction of Russian monitoring facilities on U.S. soil. That amendment, however, will not impact the availability of GLONASS ranging signals. Transportation and other critical life-safety sectors are rapidly adopting multi-constellation GNSS technology – including GLONASS – because of its ability to improve fix yield and quality.
Using GLONASS, GPS, or any other A-GNSS system would not give any government power over consumers’ 9-1-1 calls: These systems are "receive-only,” and no signals from consumer handsets are ever transmitted to a GNSS satellite.
Additional points from CTIA: The Wireless Association:
The Find Me 911 Coalition’s arguments against the APCO-NENA-Carrier E911 Location Accuracy roadmap that references A-GNSS are misplaced because A-GNSS is an addition to—not a replacement for—GPS that can only improve positioning data.
- While GPS currently plays a major role in determining user location, adding alternative ranging sources such as GLONASS and other GNSS constellations, can provide devices with a larger pool of satellites, which supplies the handset with more accurate location data, and improves the odds of getting a location estimate for indoor calls.
- The National Emergency Numbering Association ("NENA”) has stressed that multi-constellation A-GNSS technologies offer "dramatic improvements in both outdoor and, critically, indoor location performance.”
GLONASS Is One of Several A-GNSS Tools That Can Be Used to Enhance Location Accuracy
- The Roadmap for Wireless E911 Location Accuracy never states that GLONASS will be the exclusive source of user location data. Indeed, the Roadmap makes clear that both GPS and GLONASS will be tested as positioning sources. The Roadmap encourages the use of additional GNSS systems as they become available in order to provide multiple, simultaneous and independent sources of location information.
- While GLONASS and the U.S. NavStar/GPS systems are the only globally-available GNSS systems currently in operation, additional GNSS constellations and frequencies are expected within the next 5-6 years. These constellations and frequencies could be valuable for improving 9-1-1 location accuracy.
The Use of GLONASS Chips in Handsets Does Not Give Russia Power Over U.S. Wireless Communications
- The FCC has repeatedly stressed that receive-only operations cannot cause interference. As such, interference to other communications is not a concern.
- Further, because receive-only GNSS chipsets cannot transmit signals back to the space station, individual user information would not be provided to the GLONASS system.
The Installation of Earth Stations in the U.S. is Not a Prerequisite to GLONASS Functionality
- The NDAA amendment limiting construction of Russian monitoring facilities on U.S. soil does not impact the availability of GLONASS ranging signals. Other monitoring stations around the globe can still ensure the accuracy of GLONASS clock and orbit data.
- Even without U.S.-based monitoring stations, transportation and other critical life-safety sectors are rapidly adopting multi-constellation GNSS technology – including GLONASS – because of its ability to improve fix yield and quality.
About NENA, The 9-1-1 Association
As The Voice of 9-1-1™, NENA is on the forefront of all emergency communications issues. The association serves its more than 8,000 members, 44 U.S. chapters, and the greater public safety community as the only professional organization solely focused on 9-1-1 policy, technology, operations, and education issues. NENA works with all stakeholder groups to develop and carry out 9-1-1 programs and initiatives, to facilitate the creation of an IP-based Next Generation 9-1-1 system (NG9-1-1), and to establish industry-leading standards, training, and certifications.
- People, Places & Things/9-1-1magazine.com (via NENA, 1/22/15)