Federal Communications Commission
445 12th St., S.W.
Washington, D.C. 20554
News Media Information 202 / 418-0500
Released: June 15, 2016
OFFICE OF ENGINEERING AND TECHNOLOGY ANNOUNCES TECHNOLOGICAL
ADVISORY COUNCIL (TAC) NOISE FLOOR TECHNICAL INQUIRY
ET Docket No. 16-191
Comment Deadline: August 11, 2016
The FCC’s Technological Advisory Council (TAC), an advisory group to the FCC operating under the
Federal Advisory Committee Act, is investigating changes and trends to the radio spectrum noise floor to
determine if there is an increasing noise problem, and if so, the scope and quantitative evidence of such
problem(s), and how a noise study should be performed. In this public notice, the Office of Engineering
and Technology (OET) announces the TAC’s public inquiry, seeking comments and answers to questions
below for the TAC about radio spectrum noise.1
TAC Noise Floor Technical Inquiry
The TAC is requesting input to help answer questions about the study of changes to the spectrum noise
floor over the past 20 years. Noise in this context denotes unwanted radio frequency (RF) energy from
man-made sources. Like many spectrum users, TAC members expect that the noise floor in the radio
spectrum is rising as the number of devices in use that emit radio energy grows. However, in search for
concrete evidence of increased noise floors, we have found limited available quantitative data to support
this presumption. We are looking to find ways to add to the available data in order to answer important
questions for the FCC regarding this topic.
Radio spectrum noise is generated by many different types of devices. Devices that are not designed to
generate or emit RF energy but do so as a result of their operation are called Incidental Radiators. Most
electric motors, light dimmers, switching power supplies, utility transformers and power lines are
included in this category. There is little regulation governing the noise generated by these devices. Noise
from such sources is expected to be minimized with “Good Engineering Practices.”
Devices that are designed to generate RF energy for internal use, or send RF signals by conduction to
associated equipment via connected wiring, but are not intended to emit RF energy, are called
Unintentional Radiators. Computers and many portable electronic devices in use today, as well as many
new high efficiency lights, are included in this category. Current regulations limit the levels of emitted RF
energy from these devices.
Unlicensed Intentional Radiators, Industrial, Scientific, and Medical (ISM) Radiators, and Licensed
Radiators are devices that are designed to generate and emit RF energy by radiation or induction. Cellular
phones and base stations, unlicensed wireless routers, Bluetooth devices, broadcast TV and radio stations,
and radars of many types, are all examples of licensed / unlicensed intentional radiators, and microwave
ovens, arc welders, and fluorescent lighting are examples of ISM equipment. Such emitters contribute to
the noise floor with emissions outside of their assigned frequencies. These are sometimes generated as
spurious emissions, including, but not limited to, harmonics of desired frequencies and intermodulation
products. Regulations that permit the operation of these devices also specify the limits of emissions
outside of licensed or allowed (in the case of unlicensed devices) frequencies of operation.
We are looking for responses to the following questions to help us identify aspects of a study to determine
trends in the radio spectrum noise floor.
1. Is there a noise problem?
a. If so, what are the expected major sources of noise that are of concern?
b. What services are being most impacted by a rising spectrum noise floor?
c. If incidental radiators are a concern, what sorts of government, industry, and civil society
efforts might be appropriate to ameliorate the noise they produce?
2. Where does the problem exist?
i. What frequency bands are of the most interest?
i. Indoors vs outdoors?
ii. Cities vs rural settings?
iii. How close in proximity to incidental radiators or other noise sources?
iv. How can natural propagation effects be accounted for in a noise study?
i. Night versus day?
3. Is there quantitative evidence of the overall increase in the total integrated noise floor across
various segments of the radio frequency spectrum?
a. At what levels does the noise floor cause harmful interference to particular radio
b. What RF environment data from the past 20 years is available, showing the contribution
of the major sources of noise?
c. Please provide references to scholarly articles or other sources of spectrum noise
4. How should a noise study be performed?
a. What should be the focus of the noise study?
b. How should it be funded?
c. What methods should be used?
d. How should noise be measured?
i. What is the optimal instrumentation that should be used?
ii. What measurement parameters should be used for that instrumentation?
iii. At what spatial and temporal scales should noise be measured?
iv. Should the monitoring instrumentation be capable of determining the directions
of the noise sources? If so, how would those data be used?
v. Is there an optimal height above ground for measurements?
e. What measurement accuracy is needed?
i. What are the statistical requirements for sufficient data? Would these
requirements vary based on spectral, spatial and temporal factors?
ii. Can measurements from uncalibrated, or minimally calibrated, devices be
iii. Is it possible to “crowd source” a noise study?
f. Would receiver noise measurements commonly logged by certain users (e.g. radio
astronomers, cellular, and broadcast auxiliary licensees) be available and useful for noise
g. How much data must be collected to reach a conclusion?
h. How can noise be distinguished from signals?
i. Can noise be characterized and its source identified?
ii. Is there a threshold level, below which measurements should be ignored?
Interested parties may file comments up until the comment deadline indicated on the first page of this
document. Comments may be filed using the Commission’s Electronic Comment Filing System (ECFS).
See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998).
Electronic Filers: Comments may be filed electronically using the Internet by accessing the
Paper Filers: Parties that choose to file by paper must file an original and one copy of each filing.
If more than one docket or rulemaking number appears in the caption of this proceeding, filers
must submit two additional copies for each additional docket or rulemaking number.
Filings can be sent by hand or messenger delivery, by commercial overnight courier, or by firstclass
or overnight U.S. Postal Service mail. All filings must be addressed to the Commission’s
Secretary, Office of the Secretary, Federal Communications Commission.
All hand-delivered or messenger-delivered paper filings for the Commission’s Secretary
must be delivered to FCC Headquarters at 445 12th St., SW, Room TW-A325,
Washington, DC 20554. The filing hours are 8:00 a.m. to 7:00 p.m. All hand deliveries
must be held together with rubber bands or fasteners. Any envelopes must be disposed of
before entering the building.
Commercial overnight mail (other than U.S. Postal Service Express Mail and Priority
Mail) must be sent to 9300 East Hampton Drive, Capitol Heights, MD 20743.
U.S. Postal Service first-class, Express, and Priority mail must be addressed to 445 12th
Street, SW, Washington DC 20554.
People with Disabilities: To request materials in accessible formats for people with disabilities (braille,
large print, electronic files, audio format), send an e-mail to firstname.lastname@example.org or call the Consumer &
Governmental Affairs Bureau at 202-418-0530 (voice), 202-418-0432 (tty).
For further information, please contact TAC Spectrum and Receiver Performance working group cochairs
Greg Lapin, ARRL (GLapin@arrl.org) and Lynn Claudy, NAB (LClaudy@nab.org), or TAC
working group FCC liaison Robert Pavlak, FCC Office of Engineering & Technology