Human Exposure to Radiofrequency Electromagnetic Fields
| Published date | 06 April 2020 |
| Citation | 85 FR 19117 |
| Record Number | 2020-06966 |
| Section | Proposed rules |
| Court | Federal Communications Commission |
Federal Register, Volume 85 Issue 66 (Monday, April 6, 2020)
[Federal Register Volume 85, Number 66 (Monday, April 6, 2020)]
[Proposed Rules]
[Pages 19117-19126]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-06966]
[[Page 19117]]
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FEDERAL COMMUNICATIONS COMMISSION
47 CFR Parts 1, 2, 18
[ET Docket No. 19-226; FCC 19-126; FRS 16618]
Human Exposure to Radiofrequency Electromagnetic Fields
AGENCY: Federal Communications Commission.
ACTION: Proposed rule.
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SUMMARY: In this document, the Federal Communications Commission
(Commission) seeks comment on expanding the range of frequencies for
which its radiofrequency (RF) exposure limits apply; on applying
localized exposure limits above 6 GHz in parallel to the localized
exposure limits already established below 6 GHz; on specifying the
conditions and methods for averaging the RF exposure, in both time and
area, during evaluation for compliance with the RF exposure limits in
the rules; on addressing new RF exposure issues raised by wireless
power transfer (WPT) devices; and on the definition of a WPT device.
DATES: Comments are due on or before May 6, 2020, and reply comments
are due on or before May 21, 2020.
ADDRESSES: Interested parties may submit comments and replies,
identified by ET Docket No. 19-226, by any of the following methods:
Federal Communications Commission's Website: http://fjallfoss.fcc.gov/ecfs2/. Follow the instructions for submitting
comments.
Mail: Filings can be sent by hand or messenger delivery,
by commercial overnight courier, or by first-class or overnight U.S.
Postal Service mail. All filings must be addressed to the Commission's
Secretary, Office of the Secretary, Federal Communications Commission.
People with Disabilities: Contact the Commission to
request reasonable accommodations (accessible format documents, sign
language interpreters, CART, etc.) by email: [email protected] or phone:
202-418-0530 or TTY: 202-418-0432.
For detailed instructions on submitting comments and additional
information on the rulemaking process, see the SUPPLEMENTARY
INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: Martin Doczkat, email:
[email protected] of the Office of Engineering and Technology
Electromagnetic Compatibility Division; the Commission's RF Safety
Program, [email protected]; or call the Office of Engineering and
Technology at (202) 418-2470. For information regarding the Paperwork
Reduction Act (PRA) information collection requirements contained in
this document, contact Nicole Ongele, Office of Managing Director, at
(202) 418-2991 or [email protected].
SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Notice
of Proposed Rulemaking (NPRM), ET Docket No. 19-226, FCC 19-126,
adopted November 27, 2019 and released December 4, 2019. The complete
text of the document is available for public inspection and copying
from 8:00 a.m. to 4:30 p.m. Eastern Time (ET) Monday through Thursday
or from 8:00 a.m. to 11:30 a.m. on Fridays in the FCC Reference Center,
445 12th Street SW, Room CY-A257, Washington, DC 20554. The complete
text of the document is also available electronically on the
Commission's website at https://www.fcc.gov/engineering-technology or
by using the search function on the Commission's Electronic Comment
Filing System (ECFS) web page at https://fcc.gov/cgb/ecfs/ or on the
FCC's Electronic Document System (EDOCS) web page at https://apps.fcc.gov/edocs. Alternative formats (Braille, large print,
electronic files, audio format) are available to persons with
disabilities by sending an email to [email protected] or by calling the
Consumer & Governmental Affairs Bureau at (202) 418-0530 (voice), (202)
418-0432 (tty).
Comment Filing Procedures
Pursuant to Sec. Sec. 1.415 and 1.419 of the Commission's rules,
47 CFR 1.415, 1.419, interested parties may file comments and reply
comments on or before the dates 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 ECFS: http://fjallfoss.fcc.gov/ecfs2/. Filers should follow the instructions provided on the website
for submitting comments. In completing the transmittal screen, filers
should include their full name, U.S. Postal Service mailing address,
and the applicable docket number, ET Docket No. 19-226.
Paper Filers: Parties who 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 first-class or overnight U.S. Postal Service
mail. All filings must be addressed to the Commission's Secretary,
Office of the Secretary, Federal Communications Commission.
Commercial overnight mail (other than U.S. Postal Service
Express Mail and Priority Mail) must be sent to 9050 Junction Dr.,
Annapolis Junction, Annapolis, MD 220701.
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 email to [email protected] or call the
Consumer & Governmental Affairs Bureau at 202-418-0530 (voice), 202-
418-0432 (tty).
Ex Parte Rules--Permit-But-Disclose
Pursuant to Sec. 1.1200(a) of the Commission's rules, this NPRM
shall be treated as a ``permit-but-disclose'' proceeding in accordance
with the Commission's ex parte rules. Persons making ex parte
presentations must file a copy of any written presentation or a
memorandum summarizing any oral presentation within two business days
after the presentation (unless a different deadline applicable to the
Sunshine period applies). Persons making oral ex parte presentations
are reminded that memoranda summarizing the presentation must (1) list
all persons attending or otherwise participating in the meeting at
which the ex parte presentation was made, and (2) summarize all data
presented and arguments made during the presentation. If the
presentation consisted in whole or in part of the presentation of data
or arguments already reflected in the presenter's written comments,
memoranda or other filings in the proceeding, the presenter may provide
citations to such data or arguments in his or her prior comments,
memoranda, or other filings (specifying the relevant page and/or
paragraph numbers where such data or arguments can be found) in lieu of
summarizing them in the memorandum. Documents shown or given to
Commission staff during ex parte meetings are deemed to be written ex
parte presentations and must be filed consistent with Sec. 1.1206(b).
In proceedings governed by Sec. 1.49(f) or for which the Commission
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has made available a method of electronic filing, written ex parte
presentations and memoranda summarizing oral ex parte presentations,
and all attachments thereto, must be filed through the electronic
comment filing system available for that proceeding, and must be filed
in their native format (e.g., .doc, .xml, .ppt, searchable .pdf).
Participants in this proceeding should familiarize themselves with the
Commission's ex parte rules.
Initial Regulatory Flexibility Analysis
As required by the Regulatory Flexibility Act of 1980 (``RFA''),
the Commission has prepared this present Initial Regulatory Flexibility
Analysis (``IRFA'') of the possible significant economic impact on a
substantial number of small entities of the policies and rules proposed
in the NPRM. The Commission requests written public comment on this
IRFA. Comments must be filed in accordance with the same deadlines as
comments filed in response to the NRPM and must have a separate and
distinct heading designating them as responses to the IRFA. The
Commission's Consumer and Governmental Affairs Bureau, Reference
Information Center, will send a copy of this NPRM, including the IRFA,
to the Chief Counsel for Advocacy of the Small Business Administration,
in accordance with the Regulatory Flexibility Act.
Paperwork Reduction Act of 1995
The NPRM contains proposed new or modified information collection
requirements. The Commission, as part of its continuing effort to
reduce paperwork burdens, invites the general Public, the Office of
Management and Budget (OMB), and other federal agencies to comment on
the proposed information collection requirements contained in this
document, as required by the Paperwork Reduction Act of 1995, Public
Law 104-13. In addition, pursuant to the Small Business Paperwork
Relief Act of 2002, Public Law 107-198, see 44 U.S.C. 3506(c)(4), the
Commission seeks specific comment on how it might further reduce the
information collection burden for small business concerns with fewer
than 25 employees.
Synopsis
I. Introduction
1. This NPRM focuses on developing a record encompassing RF
exposure limits and compliance issues raised by recent developments in
technology that have changed the way wireless devices are used,
frequency bands of operation, how supporting wireless infrastructure is
deployed, and how RF sources are assessed for compliance with the
Commission's existing RF exposure limits. These recent developments
include using millimeter-wave and submillimeter-wave frequencies for
mobile applications, devices that can time-average their power output
to increase transmission efficiency, adaptive array antennas used by
fluctuating multi-beam sources, and devices that can transfer power
wirelessly. These and other similar applications of RF energy being
developed raise questions as to how to determine compliance with the RF
exposure limits. This NPRM seeks comment on the Commission's proposals
to apply RF exposure limits in additional frequency ranges beyond those
currently specified in the Commission's RF exposure rules; on applying
localized exposure limits above 6 GHz, in parallel with the existing
localized exposure limits below 6 GHz; on specifying the conditions and
methods for averaging RF exposure, in both time and area, during
evaluation for compliance with the rules; and on addressing new issues
raised by WPT devices.
2. This NPRM proposes methods and seeks comment on how to best
incorporate new RF technologies, new methods and techniques for RF
transmission, and new usages for a variety of spectrum bands into the
Commission's preexisting exposure framework. In particular, on the
topic of body-worn spacing during testing of cell phones, the
Commission continues to strive to ensure that such spacing represents
realistic values for present-day technology and common usage. As part
of this effort, the Commission explores the issue of approval for
equipment using new methods and technologies.
A. Extension of Exposure Limits to Additional Frequencies
3. The Commission's existing RF exposure rules provide for
evaluation of the specific absorption rate (SAR) exposure level within
the frequency range of 100 kHz to 6 GHz, and for evaluation of maximum
permissible exposure (MPE) field strength and power density within the
frequency range of 300 kHz to 100 GHz. The standards for localized SAR
that are normally applied for testing compliance of consumer devices
operating below 6 GHz were derived from the whole body limits; the
Commission currently employs a similar derivation to apply localized
limits where appropriate for testing consumer devices above 6 GHz.
However, this approach is not formalized in the Commission's rules.
Previously, the Commission sought comment on whether it should
establish specific exposure limits and protocols outside the frequency
ranges presently used for evaluation of SAR and/or MPE. Further, some
inductive wireless chargers operate at frequencies below 100 kHz, and
Commission staff have been approached by parties seeking guidance on
how to determine compliance for wireless car chargers generally
operating at similarly low frequencies.
4. The Commission is aware of three existing guidelines for RF
exposure that extend to frequencies below 100 kHz: International
Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines for
Limiting Exposure to Time-Varying Electric and Magnetic Fields (1Hz--
100 kHz) (2010); Institute of Electrical and Electronic Engineers, Inc.
(IEEE) Standard for Safety Levels with Respect to Human Exposure to
Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz (IEEE Std
C95.1-2005) and Standard for Safety Levels with Respect to Human
Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300
GHz (IEEE Std C95.1-2019); and Health Canada Safety Code 6--Limits of
Human Exposure to Radiofrequency Electromagnetic Energy in the
Frequency Range from 3 kHz to 300 GHz (2015). While these guidelines
are aimed at prevention of electrostimulation due to electric fields
induced internally within the human body in the presence of an external
electromagnetic field outside the body and have similar values for
limiting the internal electric field (Ei), they have
different approaches to the dosimetry used to derive their respective
MPE limits on external fields from those Ei values. The
Commission seeks comment on the significance of the difference between
these guidelines.
5. While each of the standards appears to provide appropriate
Ei guidelines, the ICNIRP 2010 guidelines are the most
widely accepted from an international perspective. The Commission
proposes to adopt limits on Ei similar to the ICNIRP 2010
guidelines into its rules for frequencies between 3 kHz to 10 MHz. The
Commission does not propose to apply these guidelines below 3 kHz. The
Commission seeks comments on these proposals and other relevant and
authoritative standards that commenters deem appropriate for
consideration.
6. The Commission proposes to overlay ICNIRP 2010
electrostimulation limits for Ei on its existing SAR limits
for frequencies between 100 kHz and 10
[[Page 19119]]
MHz. Because of the fast response time of neural stimulation relative
to heating, it is appropriate to apply electrostimulation limits
without time averaging (in addition to time-averaged SAR limits) to
fields at frequencies well above 100 kHz. This proposal would place
Ei alongside SAR as a co-primary limit between 100 kHz and
10 MHz (i.e., both Ei and SAR limits must be met between 100 kHz and 10
MHz). The Commission does not propose to amend or extend its MPE limits
on external fields. By not amending or extending MPE limits on external
fields, the Commission's policy that MPE limits are secondary remains
intact. Guidance on how to comply with both limits within this
frequency range may be developed as necessary for particular
applications. The Commission proposes that its policy on recommended
best practices for evaluation techniques to comply with both
Ei and SAR in the frequency range between 100 kHz and 10 MHz
should be contained in its Bulletins and in other supplemental
materials, such as the Commission's Office of Engineering and
Technology Laboratory's Knowledge Database (KDB). The Commission seeks
comment on these proposed numerical limits and on the guidance for
demonstrating compliance with such limits.
7. Although the radio spectrum is managed up to 3,000 GHz (3 THz),
the Commission's exposure limits are currently specified only up to 100
GHz. The Commission is unaware of any reason the limits should be
different above 100 GHz. As frequency increases up to 3,000 GHz (3
THz), body penetration is reduced and ultimately approaches zero.
Accordingly, there is no reason to expect that thermal effects will
effectively change at the increasingly higher frequencies. Accordingly,
the Commission proposes to extend the same constant exposure limits
that presently apply from 6 GHz to 100 GHz up to an upper frequency of
3,000 GHz (3 THz), which is considered to be the upper bound of
existing radiofrequency bands. Starting at 300 GHz or a wavelength of
1,000 micrometers ([micro]m), standards have been developed for lasers
primarily for application in industrial settings. In an effort by
standards bodies to match the laser standards, RF limits have been
increased at millimeter wave frequencies; however, the Commission does
not feel it is appropriate to relax its limits at higher frequencies
for exposure from consumer communication devices, considering the
already minimal skin depth at 100 GHz. Accordingly, the Commission
proposes to extend its existing exposure limits to 3,000 GHz (3 THz) to
stay ahead of the possibility of technologies being introduced that are
nascent or unknown today. The Commission notes that most of the
services being contemplated in the Spectrum Horizons proceeding in ET
Docket No. 18-21 operate within the 95-275 GHz frequency range, but
there may be other potential applications or services being
contemplated above this frequency range. The Commission seeks comment
on this proposal. Specifically, it seeks comment on the frequency range
over which these proposed limits would apply.
B. Localized Exposure Limits for Higher Frequencies
8. New technologies that employ techniques such as adaptive array
antennas created by fluctuating multi-beam sources create complex
energy fields that present challenges for current RF measurement
methods. Because portable devices are being developed for operation at
higher frequencies for future 5G services, the Commission proposes a
localized exposure limit above 6 GHz of 4 mW/cm\2\ averaged over 1
cm\2\ for the general population, applicable up to the upper frequency
boundary of 3 THz, and seeks comment on this proposal. The Commission
notes that both the ICNIRP guidelines and the IEEE standards specify a
spatial maximum power density of 20 times the whole-body MPE limit
(e.g., between 3 and 10 GHz), generally averaged over 1 cm\2\. The
Commission proposes a localized exposure limit above 6 GHz for
occupational settings of 20 mW/cm\2\ averaged over 1 cm\2\, which is
consistent with the typical ratio of 5:1 for the occupational limits
relative to the general population limits. The Commission tentatively
concludes not to adopt an extremity limit at this time.
9. The proposed general population localized power density value of
4 mW/cm\2\ matches the exposure limit specified at 6 GHz in the IEEE
Std C95.1-1991 standard referenced in the Commission's rules. Based on
planar models, this standard suggests that a power density of 4 mW/
cm\2\ just above 6 GHz is consistent with the Commission's 1-gram SAR
limit of 1.6 W/kg at 6 GHz. Also, the thermal perception threshold at
frequencies approaching 100 GHz for large areas of exposure is
indicated at about 4 mW/cm\2\. Maintaining 4 mW/cm\2\ across the entire
frequency range of 6 GHz to 3 THz will avoid any potential
discontinuity between SAR and power density limits at 6 GHz, while also
preventing the possibility of perception of warmth at higher
millimeter-wave frequencies. The Commission seeks comment on all
elements of this proposal, and on whether its lower-power exemptions
above 6 GHz should be changed for a localized power density limit in
this frequency range.
10. Recognizing the ongoing work in standards bodies to establish
an in-tissue power density in lieu of free-space power density--
analogous to SAR below 6 GHz--the Commission also seeks comment on
whether it should instead adopt such a limit, and if so what that limit
should be, or if it should withhold consideration of an in-tissue power
density limit until after the standards have been published at a later
date. Commenters may also propose other approaches for determining
appropriate exposure limits at higher frequencies, with an analysis and
justification for using any such protocol.
C. Averaging Area for Higher Frequencies
11. In the 2016 Spectrum Frontiers R&O and FNPRM, the Commission
acknowledged as reasonable a spatial averaging area of 20 cm\2\ for
power density above 10 GHz--as provided by ICNIRP for a whole-body
exposure limit. However, as the Commission continues to consider this
issue, it finds little support in the technical literature for
specifying a large averaging area with respect to the whole-body limit
when an averaging area for a spatial maximum limit for localized
exposure is stipulated. Moreover, ICNIRP maintains an averaging area of
1 cm\2\ for spatial maximum power densities over the frequency range of
10 GHz to 300 GHz. There is growing consensus that a range of from one
to a few square centimeters would be a more appropriate averaging area
for localized spatial maximum power density limits rather than the much
larger values (20 cm\2\ or 100 cm\2\) that are provided for the whole-
body limits in recent published versions of technical standards, e.g.,
ICNIRP and IEEE.
12. For the reasons noted, the Commission proposes a 1 cm\2\
averaging area to be applicable to localized exposure conditions where
the averaged power density would not exceed 4 mW/cm\2\ for the general
population (20 mW/cm\2\ for occupational settings). The 1 cm\2\ area is
approximately the same size as any of the surfaces of a 1-g cube used
for portable device SAR evaluation below 6 GHz in the Commission's
rules, and the Commission notes that this is the guidance that the FCC
Laboratory currently offers for pertinent equipment authorizations. The
Commission invites comment on this proposal. It also seeks comment on
whether it may also be
[[Page 19120]]
appropriate to specify a spatial peak limit coupled with this 1 cm\2\
averaging area to avoid significant excursions under actual non-uniform
exposure conditions on a millimeter scale. The Commission is aware that
this 1 cm\2\ averaging area is generally smaller than the actual size
of antenna arrays being contemplated for use by millimeter-wave
portable devices, and it seeks comment on whether this factor presents
insuperable or significant difficulties, and on other technically valid
and practical alternatives.
D. Transmitter-Based and Device-Based Time-Averaging
13. Recent technology has been developed to allow for the
optimization of the time-averaged transmit power of a device over a
predefined time window, using past transmit power levels as a reference
to determine the maximum time-averaged SAR over that period. Based on
the device's own management of time-averaged SAR, a maximum allowable
transmit power for a future fixed time interval would be determined.
The device would then operate at a power equal to or less than the
maximum allowable transmit power, depending on factors such as the
amount of data to be transmitted and network conditions. The device
would either back off from a higher transmit power to a lower power
when the calculated time-averaged SAR approaches the SAR limit, or the
device could transmit at a higher power when the device gains an
additional margin between the calculated time-averaged SAR and the SAR
limit. The recent generation of wireless devices (e.g., 4G LTE)
transmit in short bursts that are variable depending on operational
network and user demands. The Commission's current rules for source-
based time-averaging do not account for the variable nature of such
transmissions. The technology being developed utilizes both the power
level and the time-averaging duration in a dynamic manner, depending on
the operating conditions of the device, to determine SAR compliance in
real time. For example, a device could temporarily increase power to
accommodate a high upload rate and/or poor propagation conditions, and
then reduce power during less demanding periods based on the available
SAR margin for the designated time-averaging period.
14. The Commission proposes that such active accounting and control
of the instantaneous output power of the device be defined as device-
based time averaging in its rules, because the Commission expects,
especially for portable devices with multiple transmitters, that the
cumulative transmissions from all RF sources in the device be accounted
for in the SAR margin calculations. The Commission recognizes that a
device may have a plurality of RF sources, some of which might be
power-controlled by the device and others which might not, and so it
seeks comment on how to reliably and predictably distinguish any such
device from a conventional device intending to be certified under its
existing source-based time-averaging rules.
15. The Commission seeks comment on whether to permit this device-
based time averaging where the instantaneous transmit power and
duration of each transmission burst can be managed by the device over
some time period in a way that will ensure compliance with the RF
exposure rules. It also seeks input as to what specifications it should
adopt that will confirm compliance and be applied clearly and
consistently to devices coming on the market. The Commission proposes
to allow a practical extension of its existing ``source-based''
definition in its rules to include ``device-based'' time averaging. The
Commission proposes to add this definition to distinguish such a device
from those devices already being authorized, and recognizes its
responsiveness and applicability to an individual RF source while
compliance is ultimately controlled by the device itself, based on the
device tracking transmission bursts and power levels over time.
16. It is unclear how SAR measurement results based on static
conditions at certain power levels may be applied to support device
compliance for dynamic conditions where both operational and user
exposure conditions are continuously changing. It will be necessary to
select the various parameters for applying source-based time-averaging
to non-periodic transmissions that are random and dynamic, which can be
influenced by device operating configurations, network and propagation
conditions, and user operating conditions to ensure that the final
measured exposure values still provide sufficient margins for various
use configurations. The Commission seeks comment on the range and type
of parameters that should be considered to apply the proposed time-
averaging principles. For example, is it possible to develop one or
more standard transmission sequences that would reasonably replicate
typical operating conditions? Alternatively, would the averaging be
demonstrated through modeling of the device's software or firmware, and
how would this modeling be implemented? How will the Commission
determine that the device software and/or firmware achieve compliance?
The Commission seeks comment on the above and any other factors as they
may relate to consideration of device-based time-averaging in the
equipment authorization process.
17. With respect to the appropriate time-averaging period, the
Commission notes two references for specifying time-averaging limits:
(1) The ICNIRP standard that provides for averaging over 6 minutes at
10 GHz, and reduces to 10 seconds at 300 GHz on a complex basis; and
(2) the IEEE standard that provides for an averaging time of 25 minutes
at 6 GHz, dropping to 10 seconds at 300 GHz. However, since the
Commission does not limit temporal-peak SAR or power density, all of
the energy available in a time-averaging period could be deposited in
an instant, resulting in a well-defined temperature rise, yet still be
compliant with the rules. Thus, using the extended time-averaging
periods of 6 or 30 minutes as set forth in the Commission's rules in
other contexts, or either of the alternative time windows specified by
ICNIRP and IEEE, could allow for inappropriate temperature rises in
extreme cases when intense exposure occurs for only a brief period. By
reducing the time-averaging period, the maximum possible temperature
rise can be limited to a reasonable magnitude. The potential
temperature rise ([Delta]T) due to an impulse exposure is proportional
to the product of the allowed continuous-spatial-peak SAR
(SARcsp) and the time-averaging period ([Delta]t), so that a
maximum time-averaging period ([Delta]t) can be calculated from a
specified temperature rise ([Delta]T) from [Delta]t =
c[middot][Delta]T/SARcsp where c is the specific heat of
tissue. SARcsp at higher frequencies occurs at the skin
surface, and it is dependent on the SAR or power density limit (for
this calculation 1.6 mW/g or 4.0 mW/cm\2\), as well as the depth of
energy absorption into tissue. In turn, the depth of absorption is
frequency-dependent. Determination of SARcsp was approached
with standard calculations using a planar model of uniform dry skin.
Based on this approach, 100 seconds is a supportable averaging time up
to about 3 GHz, with smaller averaging times down to one second at
higher frequencies. This would permit a device to actively track its RF
emissions while limiting potential temperature rise in tissue due to an
impulse to a value of about 0.1[deg]C, less than would be perceptible
by the general population. Therefore, the Commission proposes and seeks
comment on the following
[[Page 19121]]
maximum time windows to be allowed for any frequency for devices
seeking to implement device-based time averaging techniques:
Proposed Maximum Averaging Times for Device-Based Time-Averaging
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Frequency (GHz)............................. 95
Time (seconds).............................. 100 49 27 14 7 4 3 2 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
In deriving this table, as a matter of simplicity and practicality,
the Commission considered the bands and bandwidths it expects will be
utilized for various types of devices and services, and developed
distinct parameters for each frequency range. The Commission seeks
comment on this approach and whether it has best delineated these
frequency ranges for the purpose of time-averaging limits. Any comment
should include a rigorous technical analysis in support of the position
that is advocated.
E. Wireless Power Transfer Devices
18. Definition. WPT devices have been authorized for several years
under the Commission's Part 15 rules or Part 18 rules, depending on
whether any communication functionality is provided between the
transmitting unit (TU) and the receiving unit (RU). These new and
enhanced WPT products will seek an ubiquitous position in modern
households and workplaces, and will require unique considerations in
the equipment authorization process. Accordingly, the Commission
proposes to define WPT devices under Part 18 of its rules as follows: A
wireless power transfer (WPT) device is a category of Industrial,
Scientific, and Medical (ISM) equipment which generates and emits RF
energy for local use by inductive, capacitive, or radiative coupling,
for transfer of electromagnetic energy between a power transfer unit
(TU) and receiving unit(s) (RU) of a WPT system.
19. The Commission seeks comment on the proposed definition. Is
there an alternative definition that would better reflect the
technological developments in this area? It also seeks to allow non-
communications feedback--for example, the RU modulates its resistance
to create a ``feedback'' to the TU to indicate its charge level--as
being compliant with Part 18 rules. Based on the distinction between
locally-operated wireless power transfer equipment and wireless power
transfer equipment that operates at a distance, should the Commission
also consider a separate definition for wireless power transfer
equipment that provides for the charging of receiving units located at
a distance from the transfer unit, as this type of equipment may not
meet the above proposed definition for ``local'' operation? The
Commission invites comments and input on these issues.
20. Locally operated wireless power transfer systems. Part 18
allows the use of potentially unlimited power if a device operates
within a designated Industrial, Scientific and Medical (ISM) frequency
band, so long as the device operates ``locally.'' Because the
Commission's rules do not define what would constitute ``local'' usage,
measurement and compliance challenges arise in assessing wireless power
transfer devices that provide charging of receiving units located at a
distance from the wireless power transfer transmitting unit. The
Commission seeks comment on whether the term ``local'' should be
defined in terms of distance between the transmitting and receiving
units. If the Commission defines ``local'' based on this distance, what
is the maximum distance between the transmitting and receiving units
that should be considered as ``local'' operation?
21. The Commission notes that the International Special Committee
on Radio Interference (CISPR) is considering a definition for the
primary device of a wireless power transfer system that states that the
term ``local'' is used differently in the context of wireless power
transfer from other ISM devices: ``for the case of WPT systems that
operate inductively, `local' may imply that the separation distance
between the primary (TU) and secondary (RU) WPT devices should not be
greater than 50 centimeters (cm).'' Based on CISPR's proposal, should
the Commission use 50 cm as the maximum distance for wireless power
transfer devices that operate ``locally'' (excluding wireless power
transfer at-a-distance devices, as discussed below) under Part 18?
22. Wireless power transfer at-a-distance. The Commission seeks
comment on a suitable definition and operating parameters for wireless
power transfer devices that provide charging of receiving units located
at a distance from the power transfer unit (i.e., 50 cm or greater),
with future developments intended at distances suitable for room-size
operation, and while the RU is in motion. This would cover wireless
power transfer devices that do not meet the definition of a locally
operated wireless power transfer device, i.e., within a proposed
maximum distance between the transmitting and receiving unit(s) as
discussed above. Should the Commission consider the size and coherence
of the electromagnetic field created, rather than its distance from the
transmitting unit? The challenge with these types of wireless power
transfer devices is that charging at a distance can create an RF field
distribution in three dimensions with an undefined or varying beam
shape depending on the design. Moreover, the location of maximum RF
exposure will be an area where various beams intersect, and the
direction/location and intensity of the beams can change with the
location of the target receiving unit(s). Instead--or in addition--
should the size and/or shape of the maximum field determine whether the
energy is used in reference to the distance between the transmitting
unit and any receiving unit(s)? What parameters should be used for such
a consideration?
23. The Commission further seeks comment on what factors it should
consider to ensure that the RF beam from the transmitting unit is
closely concentrated at the receiving unit, such that RF energy along
the path(s) does not exceed the applicable RF exposure limit for any
human that may be situated along the path(s), or create the potential
for harmful interference to other services. How should the Commission
evaluate compliance of wireless power transfer at-a-distance devices
with potential movements of humans in the RF field and the potential
for very close proximity of the receiving unit to humans? The
Commission believes that these devices should comply with its rules
under all operating conditions, including movements of people around
and in the field. Should the Commission propose to establish frequency
bands and power limits specifically for wireless power transfer at-a-
distance devices either under Part 15 or Part 18 of its rules,
including operation in designated ISM frequency bands (instead of
allowing unlimited power in these bands, as Part 18 currently permits)?
If the Commission establishes power limits, what should be the basis
for such limits, and should any consideration be given
[[Page 19122]]
to potential harmful interference to other non-part 18 devices, given
the popularity of these ISM frequency bands for consumer devices? With
respect to the potential for harmful interference from wireless power
transfer devices to active medical devices that may be worn or
implanted (e.g., body worn insulin pumps, implantable cardiac
pacemakers, implantable deep brain stimulators (DBS), spinal cord
stimulators, and the like), what mitigation techniques should be
required?
24. Finally, the Commission seeks input on the following issues:
Under what category of spectrum use should the Commission consider
wireless power transfer, e.g., either ISM under Part 18, Part 15, or
new rule part? What radio frequency bands are most suitable for
wireless power transfer? What steps are required to ensure that
radiocommunication services, including the radio astronomy service, as
well as active medical devices, as indicated above, are protected from
wireless power transfer operations?
25. Certification. Under Part 18, wireless power transfer equipment
is currently authorized pursuant to the Supplier's Declaration of
Conformity (SDoC) rules (formerly the Declaration of Conformity rules),
with the option to use the Certification rules.
26. Because of the continuing evolution of wireless power transfer
technology, and the potential use at higher power and in closer
proximity to humans, the Commission proposes to require wireless power
transfer equipment for both consumer and non-consumer applications to
be subject to its Certification rules. Certification will allow the
Commission to ensure that a wireless power transfer device complies
with its RF exposure rules which may be achieved by determining whether
the device qualifies for an RF exposure exemption, or whether a routine
RF exposure evaluation is required. The FCC Laboratory presently
provides guidance that requires applicants for authorization of
wireless power transfer devices to consult with the FCC Laboratory on
measurement procedures prior to equipment authorization, but exempts
certain low-power wireless power transfer devices from this requirement
(KDB Publication 680106). These low-power wireless power transfer
devices include those that operate on frequencies below 1 MHz, at power
levels less than 15 watts, only in mobile device exposure condition
(>20 cm from the body), and only use single primary and secondary coils
in close proximity. The Commission seeks comment on whether it should
adopt a rule to exempt such low-power wireless power transfer devices
from requiring certification and instead allow them to continue to be
authorized using its SDoC procedure. In addition, are there other
criteria the Commission should consider when exempting wireless power
transfer devices from the certification requirement and, if so, what
are they, and why?
II. Initial Regulatory Flexibility Analysis
27. As required by the Regulatory Flexibility Act of 1980 (RFA),
the Commission prepared an Initial Regulatory Flexibility Analysis
(IRFA) of the possible significant economic impact on a substantial
number of small entities by the policies and rules proposed in the
NPRM. The Commission requests written public comment on the IRFA, which
is contained in Appendix C to the NPRM. Comments must be identified as
responses to the IRFA and must be filed by the deadline for comments
provided in this NPRM.
28. In the IRFA, the Commission noted that the National
Environmental Policy Act of 1969 (NEPA) requires agencies of the
Federal Government to evaluate the effects of their actions on the
quality of the human environment. To meet its responsibilities under
NEPA, the Commission has adopted requirements for evaluating the
environmental impact of its actions. One of several environmental
factors addressed by these requirements is human exposure to
radiofrequency (RF) energy emitted by FCC-regulated transmitters,
facilities, and devices.
29. The NPRM proposes to amend Parts 1, 2, and 18 of its rules
relating to the compliance of FCC-regulated transmitters, facilities,
and devices with the guidelines for human exposure to radiofrequency
(RF) energy. Specifically, the Commission is proposing to make certain
revisions in its rules that it believes will result in more efficient,
practical and consistent application of its RF exposure compliance
procedures. The NPRM seeks to develop a record that will enable the
Commission to meet the challenges presented by evolving technological
advances not resolved in the previous RF exposure proceedings. The NPRM
seeks comment on expanding the range of frequencies for which the RF
exposure limits apply; on applying localized exposure limits above 6
GHz in parallel with the localized exposure limits already established
below 6 GHz; on specifying the conditions under which and the methods
by which the limits are averaged, in both time and area, during
evaluation for compliance with the rules; and on addressing new issues
raised by Wireless Power Transfer devices.The proposed action is
authorized under Sections 1, 4(i), 4(j), 301, 203, 303(r), 307, 308,
309, 332(a)(1), 332(c)(7)(B)(iv), and 403 of the Communications Act of
1934, as amended, 47 U.S.C. 151, 154(i), 154(j), 301, 302a, 303(r),
307, 308, 309, 332(a)(1), 332(c)(7)(B)(iv), 403; the National
Environmental Policy Act of 1969, 42 U.S.C. 4321 et seq.; and Section
704(b) of the Telecommunications Act of 1996, Public Law 104-104.
30. The Commission identified the small entities to which the
proposed rules would apply as being made up of entities from the
following categories: International Broadcast Stations; Satellite
Telecommunications Providers; All Other Telecommunications; Fixed
Satellite Small Transmit/Receive Earth Stations; Fixed Satellite Very
Small Aperture Terminal (VSAT) Systems; Mobile Satellite Earth
Stations; Wireless Telecommunications Carriers (except satellite);
Licenses Assigned by Auction; Paging Services; 2.3 GHz Wireless
Communications Services; 1670-1675 MHz Services; Wireless Telephony;
Broadband Personal Communications Service; Advanced Wireless Services;
Narrowband Personal Communications Services; Lower 700 MHz Band
Licensees; Upper 700 MHz Band Licensees; 700 MHz Guard Band Licensees;
Specialized Mobile Radio, 220 MHz Radio Service--Phase I Licensees; 220
MHz Radio Service--Phase II Licensees; Private Land Mobile Radio; Fixed
Microwave Services; 39 GHz Service; Local Multipoint Distribution
Service; 218-219 MHz Service; Location and Monitoring Service; Rural
Radiotelephone Service; Air-Ground Radiotelephone Service; Aviation and
Marine Radio Services; Offshore Radiotelephone Service; Multiple
Address Systems; 1.4 GHz Band Licensees; Incumbent 24 GHz Licensees;
Future 24 GHz Licensees; Broadband Radio Service and Educational
Broadband Service; Television Broadcasting; Radio Broadcasting;
Auxiliary, Special Broadcast, and Other Program Distribution Services;
Multichannel Video Distribution and Data Service; Amateur Radio
Service; Personal Radio Services; Public Safety Radio Services; IMTS
Resale Carriers; and Wireless Carriers and Service Providers.
31. The proposed rules in the NPRM do not duplicate, overlap, or
conflict with other Federal rules. The proposals being made in the NPRM
may require
[[Page 19123]]
additional analysis and mitigation activities regarding compliance with
the Commission's RF exposure limits for certain facilities, operations,
and transmitters, such as some wireless base stations, particularly
those on rooftops, and some antennas at multiple transmitter sites. In
other cases, current analytical requirements are being relaxed. The
Commission also sought comments on potential alternatives.
Statement of Authority for the Actions Proposed
32. Sections 1, 4(i), 4(j), 301, 303(r), 307, 308, 309, 332(a)(1),
332(c)(7)(B)(iv), and 403 of the Communications Act of 1934, as
amended, 47 U.S.C. 151, 154(i), 154(j), 301, 303(r), 307, 308, 309,
332(a)(1), 332(c)(7)(B)(iv), 403; the National Environmental Policy Act
of 1969, 42 U.S.C. 4321, et seq.; and section 704(b) of the
Telecommunications Act of 1996, Public Law 104-104.
List of Subjects in 47 CFR Parts 1, 2, and 18
Communications equipment, Radio.
Federal Communications Commission.
Cecilia Sigmund,
Federal Register Liaison Officer.
Proposed Rules
For the reasons discussed in the preamble, the Federal
Communications Commission proposed to amend 47 CFR parts 1, 2, and 18
as follows:
PART 1--PRACTICE AND PROCEDURE
0
1. The authority citation for part 1 continues to read as follows:
Authority: 47 U.S. C chs. 2, 5, 9, 13; 28 U.S.C. 2461 note,
unless otherwise noted.
0
2. Section 1.1307 is amended by adding in alphabetical order the
definition of ``Device-based time averaging'' to paragraph (b)(2) to
read as follows:
Sec. 1.1307 Actions that may have a significant environmental
effect, for which Environmental Assessments (EAs) must be prepared.
* * * * *
(b) * * *
(2) * * *
Device-based time averaging is where the instantaneous transmit
power and duration of each transmission burst is managed by the device
over some specified time-averaging period to ensure compliance with the
RF exposure limits.
* * * * *
0
3. Section 1.1310 is revised to read as follows:
Sec. 1.1310 Radiofrequency radiation exposure limits.
(a) Between 3 kHz and 10 MHz (inclusive), internal electric field
limits as set forth in paragraph (f) of this section shall be used to
evaluate the environmental impact of human exposure to RF radiation as
specified in Sec. 1.1307(b). Specific absorption rate (SAR) shall be
used to evaluate the environmental impact of human exposure to
radiofrequency (RF) radiation as specified in Sec. 1.1307(b) within
the frequency range of 100 kHz to 6 GHz (inclusive). Power density (PD)
shall be used to evaluate the environmental impact of human exposure to
radiofrequency (RF) radiation as specified in Sec. 1.1307(b) for the
frequency range above 6 GHz.
(b) The SAR limits for occupational/controlled exposure are 0.4 W/
kg, as averaged over the whole body, and a peak spatial-average SAR of
8 W/kg, averaged over any 1 gram of tissue (defined as a tissue volume
in the shape of a cube). Exceptions are the parts of the human body
treated as extremities, such as hands, wrists, feet, ankles, and
pinnae, where the peak spatial-average SAR limit for occupational/
controlled exposure is 20 W/kg, averaged over any 10 grams of tissue
(defined as a tissue volume in the shape of a cube). The PD limits for
occupational/controlled exposure are 5 mW/cm\2\, as averaged over the
whole body, and a peak spatial-average PD of 20 mW/cm\2\, averaged over
any 1 cm\2\. Exposure may be averaged over a time period not to exceed
6 minutes to determine compliance with occupational/controlled SAR
limits.
(c) The SAR limits for general population/uncontrolled exposure are
0.08 W/kg, as averaged over the whole body, and a peak spatial-average
SAR of 1.6 W/kg, averaged over any 1 gram of tissue (defined as a
tissue volume in the shape of a cube). Exceptions are the parts of the
human body treated as extremities, such as hands, wrists, feet, ankles,
and pinnae, where the peak spatial-average SAR limit is 4 W/kg,
averaged over any 10 grams of tissue (defined as a tissue volume in the
shape of a cube). The PD limits for general population/uncontrolled
exposure are 1 mW/cm\2\, as averaged over the whole body, and a peak
spatial-average PD of 4 mW/cm\2\, averaged over any 1 cm\2\. Exposure
may be averaged over a time period not to exceed 30 minutes to
determine compliance with general population/uncontrolled SAR limits.
(d)(1) Evaluation with respect to the SAR and/or PD limits in this
section must demonstrate compliance with both the whole-body and peak
spatial-average limits. Evaluation with respect to both the SAR and PD
limits in this section and in Sec. 2.1093 of this chapter, as well as
the internal electric field limits in this section where applicable,
shall be done using technically supported measurement or computational
methods and exposure conditions in advance of authorization (licensing
or equipment certification) and in a manner that facilitates
independent assessment and, if appropriate, enforcement. Numerical
computation of SAR must be supported by adequate documentation showing
that the numerical method as implemented in the computational software
has been fully validated; in addition, the equipment under test and
exposure conditions must be modeled according to protocols established
by FCC-accepted numerical computation standards or available FCC
procedures for the specific computational method.
(2) The limits for maximum permissible exposure (MPE) listed in
Table 1 to paragraph (e)(1) of this section, which have been derived
from whole-body SAR limits, may be used instead of whole-body SAR and/
or PD limits as set forth in paragraphs (a) through (c) of this section
to evaluate the environmental impact of human exposure to RF radiation
as specified in Sec. 1.1307(b), except for portable devices as defined
in 47 CFR 2.1093 as these evaluations shall be performed according to
the SAR and/or PD provisions, and internal electric field provisions
where applicable, in Sec. 2.1093 of this chapter.
(3) The MPE limits listed in Table 1 to paragraph (e)(1) of this
section, the SAR and/or PD limits as set forth in paragraph (a) through
(c) of this section and in Sec. 2.1093 of this chapter, and the
internal electric field limits listed in Table 2 to paragraph (f) of
this section are for continuous exposure, that is, for indefinite time
periods. Except for internal electric field, as described in (f) of
this section, exposure levels higher than the limits are permitted for
shorter exposure times, as long as the average exposure over a period
not to exceed the specified averaging time in Table 1 to paragraph
(e)(1) of this section or source-based time averaging requirement of
Sec. Sec. 2.1091(d)(2) and 2.1093(d)(5) for general population
exposure is less than the limits. Detailed information on our policies
regarding procedures for evaluating compliance with all of these
exposure limits can be found in the FCC's OET Bulletin 65, ``Evaluating
Compliance with FCC Guidelines for Human Exposure to Radiofrequency
Electromagnetic Fields,'' and in supplements to Bulletin
[[Page 19124]]
65, all available at the FCC's internet website: http://www.fcc.gov/rfsafety and in the Office of Engineering and Technology (OET)
Laboratory Division Knowledge Database (KDB) (https://www.fcc.gov/kdb).
Note 1 to Paragraph (d): SAR is a measure of the rate of energy
absorption due to exposure to RF electromagnetic energy. These SAR
limits to be used for evaluation in paragraphs (a) through (d) of
this section are based generally on criteria published by the
American National Standards Institute (ANSI) for localized SAR in
Section 4.2 of ANSI/IEEE Std C95.1-1992 These criteria for SAR
evaluation are similar to those recommended by the National Council
on Radiation Protection and Measurements (NCRP) in NCRP Report No.
86, Section 17.4.5. Limits for whole body SAR and peak spatial-
average SAR are based on recommendations made in both of these
documents.
(e)(1) Table 1 to paragraph (e)(1) sets forth limits for Maximum
Permissible Exposure (MPE) to radiofrequency electromagnetic fields.
Table 1 to paragraph (e)(1)--Limits for Maximum Permissible Exposure (MPE)
----------------------------------------------------------------------------------------------------------------
Electric field Magnetic field Power density (mW/ Averaging time
Frequency range (MHz) strength (V/m) strength (A/m) cm\2\) (minutes)
----------------------------------------------------------------------------------------------------------------
(A) Limits for Occupational/Controlled Exposure
----------------------------------------------------------------------------------------------------------------
0.3-3.0............................. 614 1.63 *100 6
3.0-30.............................. 1842/f 4.89/f *900/f\2\ 6
30-300.............................. 61.4 0.163 1.0 6
300-1,500........................... ................. ................. f/300 6
1,500-3,000,000..................... ................. ................. 5 6
----------------------------------------------------------------------------------------------------------------
(B) Limits for General Population/Uncontrolled Exposure
----------------------------------------------------------------------------------------------------------------
0.3-1.34............................ 614 1.63 *100 30
1.34-30............................. 824/f 2.19/f *180/f\2\ 30
30-300.............................. 27.5 0.073 0.2 30
300-1,500........................... ................. ................. f/1500 30
1,500-3,000,000..................... ................. ................. 1.0 30
----------------------------------------------------------------------------------------------------------------
f = frequency in MHz. * = Plane-wave equivalent power density, electric and magnetic field strengths are root-
mean-square (rms).
Note 2 to Paragraph (E)(1): The MPE limits in Table 1 to
paragraph (e)(1) of this section are based generally on criteria
published by the NCRP in NCRP Report No. 86, Sections 17.4.1,
17.4.1.1, 17.4.2 and 17.4.3 In the frequency range from 100 MHz to
1500 MHz, these MPE exposure limits for field strength and power
density are also generally based on criteria recommended by the ANSI
in Section 4.1 of ``ANSI/IEEE Std C95.1-1992. Peak spatial-average
PD limits of 4 mW/cm\2\ for general population/uncontrolled exposure
and 20 mW/cm\2\ for occupational/controlled exposure in the
frequency range from 6 GHz to 300 GHz are generally based on
criteria recommended at 6 GHz by the ANSI in Section 4.4 of ANSI/
IEEE Std C95.1-1992, and on thermal perception thresholds at
frequencies above 6 GHz.
* * * * *
Note 3 to paragraph (F): Internal electric field shall be used
to evaluate the environmental impact of human exposure to
radiofrequency (RF) radiation as specified in Sec. 1.1307(b) within
the frequency range of 3 kHz to 10 MHz (inclusive). Internal
electric fields shall be determined as a vector average in a
contiguous tissue volume of 2 x 2 x 2 cubic millimeters. Internal
electric fields induced by electric or magnetic fields including
transient or very short-term peak fields shall be regarded as
instantaneous values not to be time-averaged.
Table 2 to Paragraph (F)--Limits for Internal Electric Field
------------------------------------------------------------------------
Internal electric
Frequency range (MHz) field strength
(rms) (V/m)
------------------------------------------------------------------------
(A) Limits for Occupational/Controlled Exposure
------------------------------------------------------------------------
0.003-10............................................. 270f
------------------------------------------------------------------------
(B) Limits for General Population/Uncontrolled Exposure
------------------------------------------------------------------------
0.003-10............................................. 135f
------------------------------------------------------------------------
f = frequency in MHz.
Note 3 to paragraph (f): Internal electric field limits in Table
2 to paragraph (f) of this section are generally based on guidelines
recommended by the International Commission on Non-Ionizing
Radiation Protection (ICNIRP) in ``ICNIRP Guidelines for Limiting
Human Exposure to Time-Varying Electric and Magnetic Fields (1 Hz to
100 kHz).''
Note 4 to Sec. 1.1310: Sources cited in this section. 1. ANSI/
IEEE Std C95.1-1992 . ``IEEE Standard for Safety Levels with Respect
to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz
to 300 GHz,'', copyright 1992 by the Institute of Electrical and
Electronics Engineers, Inc. (IEEE), New York, New York 10017. 2.
``ICNIRP Guidelines for Limiting Human Exposure to Time-Varying
Electric and Magnetic Fields (1 Hz to 100 kHz),'' Published in
Volume 99, Issue 6, Pages 818-836, copyright 2010 by the Health
Physics Society and available at http://www.icnirp.org. 3. NCRP
Report No. 86 ``Biological Effects and Exposure Criteria for
Radiofrequency Electromagnetic Fields,'' copyright 1986 by NCRP,
Bethesda, Maryland 20814.
PART 2--FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL
RULES AND REGULATIONS
0
4. The authority citation for part 2 continues to read as follows:
Authority: 47 U.S.C. 154, 302a, 303, and 336, unless otherwise
noted.
0
5. Section 2.1091 is amended by revising paragraph (d) to read as
follows:
Sec. 2.1091 Radiofrequency radiation exposure evaluation: mobile
devices.
* * * * *
(d)(1) Applications for equipment authorization of mobile RF
sources subject to routine environmental evaluation must contain a
statement confirming compliance with the limits specified in Sec.
1.1310 of this chapter as part of their application. Technical
information showing the basis for this statement must be submitted to
the Commission upon request. In general, maximum time-averaged power
levels must be used for evaluation. All unlicensed personal
communications service (PCS) devices and unlicensed
[[Page 19125]]
NII devices shall be subject to the limits for general population/
uncontrolled exposure.
(2) For purposes of analyzing mobile transmitting devices under the
occupational/controlled criteria specified in Sec. 1.1310 of this
chapter, time averaging provisions of the limits may be used in
conjunction with maximum duty factor to determine maximum time-averaged
exposure levels under normal operating conditions.
(3) Such time averaging provisions based on maximum duty factor may
not be used in determining exposure levels for devices intended for use
by consumers in general population/uncontrolled environments as defined
in Sec. 1.1310 of this chapter. However, either ``source-based'' time
averaging, based on an inherent property of the RF source, or ``device-
based'' time averaging based on an inherent capability of the device in
direct control of the RF source, is allowed.
* * * * *
0
6. Section 2.1093 is amended by revising paragraph (d) to read as
follows:
Sec. 2.1093 Radiofrequency radiation exposure evaluation: portable
devices.
* * * * *
(d)(1) Applications for equipment authorization of portable RF
sources subject to routine environmental evaluation must contain a
statement confirming compliance with the limits specified in Sec.
1.1310 of this chapter as part of their application. Technical
information showing the basis for this statement must be submitted to
the Commission upon request. In general, maximum time-averaged power
levels must be used for evaluation. All unlicensed personal
communications service (PCS) devices and unlicensed NII devices shall
be subject to the limits for general population/uncontrolled exposure.
(2) Evaluation of compliance with the SAR limits can be
demonstrated by either laboratory measurement techniques or by
computational modeling. The latter must be supported by adequate
documentation showing that the numerical method as implemented in the
computational software has been fully validated; in addition, the
equipment under test and exposure conditions must be modeled according
to protocols established by FCC-accepted numerical computation
standards or available FCC procedures for the specific computational
method. Guidance regarding SAR, PD, internal electric field, and MPE
measurement techniques, where applicable, can be found in the Office of
Engineering and Technology (OET) Laboratory Division Knowledge Database
(KDB). The staff guidance provided in the KDB does not necessarily
represent the only acceptable methods for measuring RF exposure or RF
emissions, and is not binding on the Commission or any interested
party.
(3) For purposes of analyzing portable RF sources under the
occupational/controlled SAR criteria specified in Sec. 1.1310 of this
chapter, the time averaging provisions of these SAR criteria may be
used to determine maximum time-averaged exposure levels under normal
operating conditions.
(4) The time averaging provisions for occupational/controlled SAR/
PD criteria, based on maximum duty factor, may not be used in
determining typical exposure levels for portable devices intended for
use by consumers, such as cellular telephones, that are considered to
operate in general population/uncontrolled environments as defined in
Sec. 1.1310 of this chapter. However, either ``source-based'' time
averaging, based on an inherent property of the RF source, or ``device-
based'' time averaging based on an inherent capability of the device in
direct control of the RF source, is allowed, as described in paragraph
(d)(6) of this section.
(5) Visual advisories (such as labeling, embossing, or on an
equivalent electronic display) on portable devices designed only for
occupational use can be used as part of an applicant's evidence of the
device user's awareness of occupational/controlled exposure limits.
Such visual advisories shall be legible and clearly visible to the user
from the exterior of the device. Visual advisories must indicate that
the device is for occupational use only, refer the user to specific
information on RF exposure, such as that provided in a user manual and
note that the advisory and its information is required for FCC RF
exposure compliance. Such instructional material must provide the user
with information on how to use the device in order to ensure compliance
with the occupational/controlled exposure limits. A sample of the
visual advisory, illustrating its location on the device, and any
instructional material intended to accompany the device when marketed,
shall be filed with the Commission along with the application for
equipment authorization. Details of any special training requirements
pertinent to limiting RF exposure should also be submitted. Holders of
grants for portable devices to be used in occupational settings are
encouraged, but not required, to coordinate with end-user organizations
to ensure appropriate RF safety training.
(6) General population/uncontrolled exposure limits defined in
Sec. 1.1310 of this chapter apply to portable devices intended for use
by consumers or persons who are exposed as a consequence of their
employment and may not be fully aware of the potential for exposure or
cannot exercise control over their exposure. No communication with the
consumer including either visual advisories or manual instructions will
be considered sufficient to allow consumer portable devices to be
evaluated subject to limits for occupational/controlled exposure
specified in Sec. 1.1310 of this chapter.
(7) ``Device-based'' time averaging, based on an inherent
capability of the device in direct control of the RF source(s) within a
device, is permitted if the protocols established to track the
instantaneous transmit power over a time averaging period not to exceed
the values listed in Table 1 for the specific operating frequencies of
each transmitter have been validated against available FCC procedures
for the ``device-based'' time averaging method to be used by the
device.
Table 1 to Paragraph (d)--Maximum Averaging Times for Device-Based Time Averaging
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Frequency (GHz):............................ 95
Time (seconds):............................. 100 49 27 14 7 4 3 2 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 19126]]
* * * * *
PART 18--INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT
0
7. The authority citation for part 18 continues to read as follows:
Authority: 47 U.S.C. 4, 301, 302, 303, 304, 307.
0
8. Amend Sec. 18.107 by adding paragraph (k) to read as follows:
Sec. 18.107 Definitions.
* * * * *
(k) Wireless power transfer (WPT) equipment. A category of ISM
equipment which generates and emits RF energy for local use by
inductive, capacitive or radiative coupling, for transfer of
electromagnetic energy between a power transfer unit (TU) and receiving
unit(s) (RU) of a WPT system.
* * * * *
0
9. Add Sec. 18.123 to read as follows:
Sec. 18.123 Transition Provisions for Wireless Power Transfer
Equipment.
All wireless power transfer equipment that are manufactured,
imported, marketed or installed on or after [DATE 6 MONTHS AFTER
EFFECTIVE DATE OF FINAL RULE] shall comply with all the provisions for
wireless power transfer devices of this part.
0
10. Amend Sec. 18.203 by adding paragraph (d) to read as follows:
Sec. 18.203 Equipment authorization.
* * * * *
(d) Wireless power transfer equipment shall be authorized under the
Certification procedure prior to use or marketing, in accordance with
the relevant sections of part 2, subpart J of this chapter.
0
11. Amend Sec. 18.207 by adding paragraph (e)(6) to read as follows:
Sec. 18.207 Technical report.
* * * * *
(e) * * *
(6) For wireless power transfer equipment, a statement confirming
compliance for radio frequency radiation exposure in accordance with
the requirements in 47 CFR 1.1307(b), 1.1310, 2.1091, and 2.1093, as
appropriate. Applications for equipment authorization of RF sources
operating under this section must contain a statement confirming
compliance with these requirements. Technical information showing the
basis for this statement must be submitted to the Commission upon
request.
* * * * *
[FR Doc. 2020-06966 Filed 4-3-20; 8:45 am]
BILLING CODE 6712-01-P
