[Federal Register Volume 82, Number 76 (Friday, April 21, 2017)]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-08080]
DEPARTMENT OF COMMERCE
National Institute of Standards and Technology
Impact of Long Term Evolution Signals on Global Positioning
AGENCY: National Institute of Standards and Technology, Department of
ACTION: Notice of public meeting.
SUMMARY: The National Institute of Standards and Technology (NIST)
announces that National Advanced Spectrum and Communications Test
Network (NASCTN) will hold a public meeting on May 4, 2017 to inform
the public about the NASCTN project ``Impact of Long Term Evolution
(LTE) signals on Global Positioning System (GPS) Devices''. At this
meeting, the public will learn about this project, as described in the
report released to the public on February 15, 2017, available at:
summary of NASCTN's test methodology and an overview of the test
results will be provided as well.
DATES: The meeting will be held on Thursday, May 4, 2017, from 9:00
a.m. to 12:00 p.m. Eastern Time. To attend the meeting in person you
must register in advance by 5:00 p.m. Eastern Time on Tuesday, May 2,
2017. In order to access the WebEx you must register in advance by 5:00
p.m. Eastern Time on Wednesday, May 3, 2017. For instructions on how to
register to participate in the meeting, please see the SUPPLEMENTARY
INFORMATION section of this notice.
ADDRESSES: The meeting will be held at MITRE Campus, Building 1, 7525
Colshire Drive, McLean VA, 22102. Directions to the MITRE McLean Campus
are available at: https://www.mitre.org/sites/default/files/pdf/mclean-campus-map.pdf. The meeting will also be accessible via WebEx.
FOR FURTHER INFORMATION CONTACT: For questions about this public
meeting contact: Dr. Sheryl Genco, Communications Technology
Laboratory, NIST by email at [email protected]; telephone (303-497-
3591) or fax (303-497-6665). Please direct media inquiries to the NIST
Public Affairs Officer, Laura Ost by email at [email protected] or
SUPPLEMENTARY INFORMATION: NASCTN provides a neutral forum for
addressing spectrum-sharing challenges to accelerate the deployment of
wireless technologies among commercial and federal users. NASCTN was
created in 2015 and is a joint effort among NIST, the National
Telecommunications and Information Administration, and the United
States Department of Defense. NASCTN's mission is to provide robust
test processes and validated measurement data necessary to develop,
evaluate and deploy spectrum sharing technologies that can increase
access to the spectrum by both Federal agencies and non-federal
spectrum users. NASCTN conducts projects with private sector entities
via Cooperative Research and Development Agreements (CRADA).\1\ NASCTN
has completed the ``Impacts of LTE Signals on GPS Receivers'' project
and released the NASCTN report ``LTE Impacts on GPS'' on February 15,
2017. The report describes the project, the test methodology and the
test results and is available at: http://nvlpubs.nist.gov/nistpubs/TechnicalNotes/NIST.TN.1952.pdf.
\1\ A CRADA is the principal mechanism used by Federal
laboratories to engage in collaborative efforts with non-Federal
entities and allow the exchange of resources with private industry
to advance technologies that can then be commercialized for the
benefit of the public and the U.S. economy.
The focus of this NASCTN project, proposed by Ligado Networks in
2016 and conducted under a CRADA between NIST and Ligado Networks, was
the development of a test methodology to: (1) Investigate the impact of
LTE signals on GPS devices that operate in the GPS L1 frequency band;
and (2) perform radiated radio-frequency measurements on a
representative set of GPS devices to validate the test methodology.
At the start of the project, NASCTN convened a panel of technical
experts to develop a test plan with the following objectives: Develop a
test plan that is transparent, reproducible, and well-calibrated;
develop sound, statistically-valid data retrieval and processing
techniques; provide a clear path from measurement setup, to data
collection, to processed results; and provide data to inform
discussions between different interested parties on proper measurement
requirements. The goal
was to make reproducible measurements under clearly-defined test
conditions to isolate impacts of radiated LTE signals on GPS receivers,
and to allow others to make comparable measurements if desired. To
accomplish this, the approach aimed to measure the response of selected
GPS devices given well-controlled GPS and LTE power levels under fixed,
stable thermal noise conditions, while limiting the number of other
In May of 2016, the NASCTN team completed the draft test plan and
distributed it to a cross-section of GPS manufacturers, Federal
agencies, and spectrum regulators and released it publicly for comments
to obtain technical feedback on the proposed method. Over a two-month
period, NASCTN received 159 comments from 10 different organizations.
The NASCTN test team reviewed the comments and developed a revised test
plan in July of 2016 that addressed the technical issues raised in the
comments. The draft test plan, the revised test plan, and the
adjudicated comments from the review process are all publicly available
on the NASCTN Web site at: https://www.nist.gov/programs-projects/impact-lte-signals-gps-receivers.
Over a three-month period, from August through October 2016, NASCTN
performed the radiated measurements associated with this project at two
facilities--a semi-anechoic chamber at National Technical Systems in
Longmont, Colorado and at a fully-anechoic chamber at the NIST
Broadband Interoperability Testbed facility in Boulder, Colorado, using
the revised test plan.
NASCTN relied on technical staff from NIST and the U.S. Army's
Electronic Proving Grounds to perform and validate the measurements and
collect the data. The team was multi-disciplinary, including expertise
in GPS devices and simulation, radiated radio-frequency measurements,
timing measurements, microwave metrology, statistical analysis and data
In total, NASCTN performed 1,476 hours of testing and collected
over 19,000 data files for a variety of measurands, including carrier-
to-noise-density ratio (C/N0), 3D position error, timing
error, number of satellites in view, time to first fix, and time to
first reacquisition, that were collected from a number of GPS devices
at a baseline condition (no LTE signals present) and over a large range
of LTE signal power levels. Subsequent data processing yielded a set of
3,859 anonymized data files (780 MB) that may be requested here:
information on this NASTCN project, including the document library and
the archived draft test plan, the revised test plan, adjudicated
comments, and supplemental information, is available at: https://www.nist.gov/programs-projects/impact-lte-signals-gps-receivers.
Due to significant interest in these measurements by regulators for
assessing LTE signals on performance of GPS devices, Federal agencies,
and the GPS community, NASCTN is hosting a public meeting to provide an
overview of the project, the test methodology and the test results.
NASCTN will also answer questions on the project, the testing
methodology and the test results. The final agenda for the public
meeting will be posted on the NASCTN Web page, available at: https://www.nist.gov/communications-technology-laboratory-ctl/nasctn.
Admittance Instructions: Anyone wishing to attend the NASCTN ``LTE
Impact on GPS Devices'' public meeting must register by email to
[email protected] no later than 5:00 p.m. Eastern Time on Tuesday, May, 2
2017. Please provide your first and last name, email address, phone
number, and company affiliation in the registration email.
Seating at the public meeting may be limited, and attendance will
be ``first-come, first-served,'' on a space-available basis.
The public meeting will also be accessible via WebEx for those who
are unable to participate in person. If you wish to have access to the
WebEx, you must register in advance of the meeting by sending an email
with your first and last name, email address, phone number, and company
affiliation provided in the message to Dr. Sheryl Genco at
[email protected] no later than 5:00 p.m. Eastern Time on
Wednesday, May 3, 2017. Instructions for accessing the WebEx will be
provided by email to individuals who register.
NIST Chief of Staff.
[FR Doc. 2017-08080 Filed 4-20-17; 8:45 am]
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