Apple Park RF Exposure Study_2.pdfAPPLE INC. AT&T Site No. CCL04017
1 Apple Parkway Sprint Site No. SF96xc030
Cupertino, California T -Mobile Site No. SF14980A
Proposed Base Stations Verizon Site No. 278981
Statement of Hammett & Edison, Inc., Consulting Engineers
The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of Apple Inc.,
to evaluate the base stations for personal wireless telecommunications carriers AT&T Mobility,
Sprint, T -Mobile, and Verizon Wireless (Site Nos. CCL04017, SF96xc030, SF 14980A, and
278981 "Apple Park," respectively) proposed to be located on the Apple Park Main Building (ACO2)
at 1 Apple Parkway in Cupertino, California, for compliance with appropriate guidelines limiting
human exposure to radio frequency ("RF") electromagnetic fields.
Executive Summary
Four wireless carriers propose to install directional panel antennas behind the exterior wall of
the penthouse above the roof of the four-story Apple Park Main Building located at 1 Apple
Parkway in Cupertino. The proposed operations will comply with the FCC guidelines
limiting public exposure to RF energy; certain mitigation measures are recommended to
comply with FCC occupational guidelines.
Prevailing Exposure Standards
The U.S. Congress requires that the Federal Communications Commission ("FCC") evaluate its
actions for possible significant impact on the environment. A summary of the FCC's exposure limits
is shown in Figure 1. These limits apply for continuous exposures and are intended to provide a
prudent margin of safety for all persons, regardless of age, gender, size, or health. The most restrictive
FCC limit for exposures of unlimited duration to radio frequency energy for several personal wireless
services are as follows:
Wireless Service
Frequency Band
Occupational Limit
Public Limit
Microwave (Point -to -Point)
5-80 GHz
5.00 mW/cm2
1.00 mW/cm2
WiFi (and unlicensed uses)
2-6
5.00
1.00
BRS (Broadband Radio)
2,600 MHz
5.00
1.00
WCS (Wireless Communication)
2,300
5.00
1.00
AWS (Advanced Wireless)
2,100
5.00
1.00
PCS (Personal Communication)
1,950
5.00
1.00
Cellular
870
2.90
0.58
SMR (Specialized Mobile Radio)
855
2.85
0.57
700 MHz
700
2.40
0.48
[most restrictive frequency range]
30-300
1.00
0.20
HAMMETT & EDISON, INC.
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APPLE INC. AT&T Site No. CCL04017
1 Apple Parkway Sprint Site No. SF96xc030
Cupertino, California T -Mobile Site No. SF14980A
Proposed Base Stations Verizon Site No. 278981
General Facility Requirements
Base stations typically consist of two distinct parts: the electronic transceivers (also called "radios" or
"channels") that are connected to the traditional wired telephone lines, and the passive antennas that
send the wireless signals created by the radios out to be received by individual subscriber units. The
transceivers are often located at ground level and are connected to the antennas by coaxial cables. A
small antenna for reception of GPS signals is also required, mounted with a clear view of the sky.
Because of the short wavelength of the frequencies assigned by the FCC for wireless services, the
antennas require line -of -sight paths for their signals to propagate well and so are installed at some
height above ground. The antennas are designed to concentrate their energy toward the horizon, with
very little energy wasted toward the sky or the ground. This means that it is generally not possible for
exposure conditions to approach the maximum permissible exposure limits without being physically
very near the antennas.
Computer Modeling Method
The FCC provides direction for determining compliance in its Office of Engineering and Technology
Bulletin No. 65, "Evaluating Compliance with FCC -Specified Guidelines for Human Exposure to
Radio Frequency Radiation," dated August 1997. Figure 2 describes the calculation methodologies,
reflecting the facts that a directional antenna's radiation pattern is not fully formed at locations very
close by (the "near -field" effect) and that at greater distances the power level from an energy source
decreases with the square of the distance from it (the "inverse square law"). The conservative nature
of this method for evaluating exposure conditions has been verified by numerous field tests.
Site and Facility Description
Based upon information provided by Apple, including architectural drawings by Foster + Partners,
dated July 10, 2011, four wireless telecommunications carriers — AT&T Mobility, Sprint, T -Mobile,
and Verizon Wireless — propose to install base station antennas behind the outside wall of the
equipment penthouse atop the four-story, circular office building located at 1 Apple Parkway in
Cupertino. The antennas would be mounted at an effective height of about 69 feet above ground,
9 feet above the walkway against that wall, and would be arranged in four groupings around the
building, oriented roughly north, east, south, and west. It is noted that the Sprint and T -Mobile
antennas are mounted close together in each grouping, except to the south, where T -Mobile does not
propose to install antennas. The following information has been provided by the individual carriers:
HAMMETT & EDISON, INC.
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APPLE INC.
1 Apple Parkway
Cupertino, California
Proposed Base Stations
AT&T
AT&T Site No. CCL04017
Sprint Site No. SF96=030
T -Mobile Site No. SF14980A
Verizon Site No. 278981
• Zoning drawings by J5 Infrastructure Partners, dated November 7, 2017
• Sixteen CCI Model HPA-65F-BUU-H2 antennas, employing up to 4° downtilt
• Oriented in groups of four toward 20°T, 110°T, 200°T and 290°T
• Maximum effective radiated power 6,210 watts: 1,340 watts at WCS, 1,960 watts at AWS,
1,640 watts at PCS, 500 watts at cellular, 770 watts at 700 MHz
Sprint
• Zoning drawings by Fullerton Engineering Design, dated July 18, 2017
• Four Filtronic Model P6T2131701 antennas, employing up to 8° downtilt
• Oriented toward 80°T, 170°T, 260°T, and 350°T
• Maximum effective radiated power 3,250 watts: 1,280 watts at BRS, 1,610 watts at PCS,
360 watts at SMR
T -Mobile
• Zoning drawings by Black & Veatch, dated November 6, 2017
• Six CCI Model HPA-6517-13UU-1-12 antennas, employing up to 3° downtilt
• Oriented in pairs toward 80°T, 260°T, and 350°T (no antennas oriented toward 170°T)
• Maximum effective radiated power 3,600 watts: 1,960 watts at AWS and 1,640 watts at PCS
Verizon
• Zoning drawings by Streamline Engineering and Design, Inc., dated July 27, 2017
• Sixteen JMA Model X7CQAP-FRO-260 antennas, employing up to 6° downtiIt
• Oriented in groups of four toward 30°T, 120°T, 210°T, and 300°T
• Maximum effective radiated power 10,860 watts: 5,400 watts at AWS, 2,480 watts at PCS,
1,880 watts at cellular, 1,100 watts at 700 MHz
HAMMETT & EDISON, INC.
CONSULTING ENGINEERS C8RQ
SAN FRANCISCO Page 3 of 5
APPLE INC.
1 Apple Parkway
Cupertino, California
Proposed Base Stations
Study Results
AT&T Site No. CCL04017
Sprint Site No. SF96xc030
T -Mobile Site No. SF14980A
Verizon Site No. 278981
For a person anywhere at ground, the maximum RF exposure level due to the cumulative operation of
all four carriers, including RF emissions from similar antennas on Apple Building TA09 about
1,500 feet to the south, is calculated to be 0.038 mW/cm2, which is 6.0% of the applicable public
exposure limit. The maximum calculated level for a person on the top floor of the building is 0.90%
of the public exposure limit. The maximum calculated level at the underground garage is less than
0.1% of the public exposure limit. The maximum calculated level at the top -floor elevation of any
nearby residence is 5.9% of the public exposure limit; this occurs at the Hamptons Apartment Homes
located about 270 feet to the southwest. It should be noted that these results include several "worst-
case" assumptions and therefore are expected to overstate actual power density levels from the
proposed operation. Exposure levels on the roof of the building may exceed the applicable public
limit in certain areas, as shown in Figures 3 and 4.
Recommended Mitigation Measures
Due to their mounting locations and height, requiring passage through a locked door to reach the roof,
the carriers' antennas would not be accessible to unauthorized persons, and so no mitigation measures
are necessary to comply with the FCC public exposure guidelines. To prevent occupational exposures
in excess of the FCC guidelines, it is recommended that appropriate RF safety training, to include
review of personal monitor use and lockout/tagout procedures, be provided to all authorized personnel
who have access to the roof, including employees and contractors of the respective carriers and of
Apple. No access directly in front of the antennas themselves, such as might occur during certain
maintenance activities on the solar panels and at the view screens in front of the antennas, should be
allowed while the pertinent antennas are in operation, unless other measures can be demonstrated to
ensure that occupational protection requirements are met. As shown in Figure 4, it is recommended
that a yellow stripe be painted (centered in front of the antennas for each carrier, except T -Mobile) at
the top edge outer wall of the roof walkway, and it is recommended that explanatory signs* be posted
at the roof access ladders, at the solar panel access ladders, at the approximate mid -point of each
yellow stripe, near the solar panels above the end parts of each yellow stripe, and on the penthouse
wall in front of the antennas, readily visible from any angle of approach to persons who might need to
work in those areas.
* Signs should comply with OET-65 color, symbol, and content recommendations. Contact information for the
respective carrier should be provided (e.g., a telephone number) to arrange for access to restricted areas. The
selection of language(s) is not an engineering matter, and guidance from the landlord, local zoning or health
authority, or appropriate professionals may be required.
HaimHAMMETT & EDISON, INC.
CONSULTING ENGINEERS C8RQ
SAN FRANCISCO Page 4 of 5
APPLE INC. AT&T Site No. CCL04017
1 Apple Parkway Sprint Site No. SF96xc030
Cupertino, California T -Mobile Site No. SF14980A
Proposed Base Stations Verizon Site No. 278981
Conclusion
Based on the information and analysis above, it is the undersigned's professional opinion that
operation of the proposed base stations at 1 Apple Parkway in Cupertino, California, will comply with
the prevailing standards for limiting public exposure to radio frequency energy and, therefore, will not
for this reason cause a significant impact on the environment. The highest calculated level in publicly
accessible areas is much less than the prevailing standards allow for exposures of unlimited duration.
This finding is consistent with measurements of actual exposure conditions taken at other operating
base stations. Training authorized personnel, marking sections of the outer wall of the roof walkway,
and posting explanatory signs are recommended to establish compliance with occupational exposure
limits.
Authorship
The undersigned author of this statement is a qualified Professional Engineer, holding California
Registration Nos. E-13026 and M-20676, which expire on June 30, 2019. This work has been carried
out under his direction, and all statements are true and correct of his own knowledge except, where
noted, when data has been supplied by others, which data he believes to be correct.
rE-13-?,h4)"026
M-20676
cl Exp. 6-30-2019
March 21, 2018
HAMMETT & EDISON, INC.
CONSULTING ENGINEERS
SAN FRANCISCO
William F. Hami4tt, P.E.
707/996-5200
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Page 5 of 5
FCC Radio Frequency Protection Guide
The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission ("FCC")
to adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have
a significant impact on the environment. The FCC adopted the limits from Report No. 86, "Biological
Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields," published in 1986 by the
Congressionally chartered National Council on Radiation Protection and Measurements ("NCRP").
Separate limits apply for occupational and public exposure conditions, with the latter limits generally
five times more restrictive. The more recent standard, developed by the Institute of Electrical and
Electronics Engineers and approved as American National Standard ANSUIEEE C95.1-2006, "Safety
Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to
300 GHz," includes similar limits. These limits apply for continuous exposures from all sources and
are intended to provide a prudent margin of safety for all persons, regardless of age, gender, size, or
health.
As shown in the table and chart below, separate limits apply for occupational and public exposure
conditions, with the latter limits (in italics and/or dashed) up to five times more restrictive:
Frequency
Applicable
Range
(MHz)
0.3— 1.34
1.34— 3.0
3.0— 30
30— 300
300— 1,500
1,500— 100,000
1000
100
10
`. 0.1
ElectromaLynetic Fields (f is freauencv of emission in MHz
Electric
Magnetic
Equivalent Far -Field
Field Strength
Field Strength
Power Density
MITI)
(A/m)
(mW/cm2)
614 614
1.63 1.63
100 100
614 823.8/f
1.63 2.19/f
100 180/f
1842/ f 823.8/f
4.89/ f 2.19/f
900/ f' 1801f
61.4 27.5
0.163 0.0729
1.0 0.2
3.54* 1.59ff
4f/106 NFf1238
f/300 f/1500
137 61.4
0.364 0.163
5.0 1.0
Occupational Exposure
PCS
FM
Public
0.1 1 10 100 103 104 105
Frequency (MHz)
Higher levels are allowed for short periods of time, such that total exposure levels averaged over six or
thirty minutes, for occupational or public settings, respectively, do not exceed the limits, and higher
levels also are allowed for exposures to small areas, such that the spatially averaged levels do not
exceed the limits. However, neither of these allowances is incorporated in the conservative calculation
formulas in the FCC Office of Engineering and Technology Bulletin No. 65 (August 1997) for
projecting field levels. Hammett & Edison has built those formulas into a proprietary program that
calculates, at each location on an arbitrary rectangular grid, the total expected power density from any
number of individual radio sources. The program allows for the description of buildings and uneven
terrain, if required to obtain more accurate projections.
HAMMETT & EDISON, INC. FCC Guidelines
CONSULTING ENGINEERS
SAN FRANCISCO Figure 1
RFR.CALCTM Calculation Methodology
Assessment by Calculation of Compliance with FCC Exposure Guidelines
The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission ("FCC") to
adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have a
significant impact on the environment. The maximum permissible exposure limits adopted by the FCC
(see Figure 1) apply for continuous exposures from all sources and are intended to provide a prudent
margin of safety for all persons, regardless of age, gender, size, or health. Higher levels are allowed for
short periods of time, such that total exposure levels averaged over six or thirty minutes, for
occupational or public settings, respectively, do not exceed the limits.
Near Field.
Prediction methods have been developed for the near field zone of panel (directional) and whip
(omnidirectional) antennas, typical at wireless telecommunications base stations, as well as dish
(aperture) antennas, typically used for microwave links. The antenna patterns are not fully formed in
the near field at these antennas, and the FCC Office of Engineering and Technology Bulletin No. 65
(August 1997) gives suitable formulas for calculating power density within such zones.
For a panel or whip antenna, power density S = 0 x Ox D Px h ' in mW/Cm2,
9
sw
and for an aperture antenna, maximum power density Smax =
0.1x16xi1xP.,,
itxh2
where OBW
= half -power beamwidth of the antenna, in degrees, and
Pnet
= net power input to the antenna, in watts,
D
= distance from antenna, in meters,
h
= aperture height of the antenna, in meters, and
i?
= aperture efficiency (unitless, typically 0.5-0.8).
The factor of 0.1 in the numerators converts to the desired units of power density.
, in mW/cm2,
Far Field.
OET-65 gives this formula for calculating power density in the far field of an individual RF source:
power density S = 2.56 x 1.64 x 100 x RFF2 x ERP
4 x ;r x D2 in mW/cm2,
where ERP = total ERP (all polarizations), in kilowatts,
RFF = relative field factor at the direction to the actual point of calculation, and
D = distance from the center of radiation to the point of calculation, in meters.
The factor of 2.56 accounts for the increase in power density due to ground reflection, assuming a
reflection coefficient of 1.6 (1.6 x 1.6 = 2.56). The factor of 1.64 is the gain of a half -wave dipole
relative to an isotropic radiator. The factor of 100 in the numerator converts to the desired units of
power density. This formula has been built into a proprietary program that calculates, at each location
on an arbitrary rectangular grid, the total expected power density from any number of individual
radiation sources. The program also allows for the description of uneven terrain in the vicinity, to
obtain more accurate projections.
HEHAMMETT & EDISON, INC.
CONSULTING ENGINEERS Methodology
SAN FRANCISCO Figure 2
APPLE INC. AT&T Site No. CCL04017
1 Apple Parkway Sprint Site No. SF96xc030
Cupertino, California T -Mobile Site No. SF14980A
Proposed Base Stations Verizon Site No. 278981
Calculated RF Exposure Levels on Roof
(Antenna Arrangement Typical of Four)
Recommended Mitigation Measures
• Paint yellow caution stripes (see Figure 4)
• Post explanatory signs (see Figure 4)
• Provide training
Legend.
Less Than
Exceeds
Exceeds
Exceeds l Ox
Public
Public
Occupational
Occupational
Shaded color
blank
0
Sign type
I - Green
$- Blue
'y- Yellow
® - Orange
INFORMATION
NOTICE
CAUTION
WARNING
HAMMETT & EDISON, INC.
CONSULTING ENGINEERS
_... SAN FRANCISCO
Notes: See text.
Base drawing from Black & Veatch,
dated November 6, 2017.
Calculations performed according to
OET Bulletin 65, August 1997.
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Figure 3
APPLE INC. AT&T Site No. CCL04017
1 Apple Parkway Sprint Site No. SF96xc030
Cupertino, California T -Mobile Site No. SF14980A
Proposed Base Stations Verizon Site No. 278981
Calculated RF Exposure Levels on Walkway and Solar Panels
(Typical for Each Carrier)
Legend:
Shaded color
Boundary marking
Sign type
Verizon
AT&T
TP
Less Than
Exceeds
Public
Public
blank
■
N/A
® - Orange
1- Green
$- Blue
INFORMATION
NOTICE
HAMMETT & EDISON, INC.
CONSULTING ENGINEERS
_.... SAN FRANCISCO
Sprint
Exceeds
Exceeds IOx
Occupational
Occupational
■
'Y- Yellow
® - Orange
CAUTION
WARNING
FEET
10 0 10 20
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Figure 4