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RF Study_6.pdfAPPLE INC. 18920 Forge Drive Cupertino, California Proposed Base Stations AT&T Site No. CCL04017 T -Mobile Site No. SF14980A Verizon Site No. 519109 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, T -Mobile, and Verizon Wireless (Site Nos. CCL04017, SF 14980A, and 519109, respectively) proposed to be located on the Apple building at 18920 Forge Drive in Cupertino, California, for compliance with appropriate guidelines limiting human exposure to radio frequency ("RF") electromagnetic fields. Executive Summary Three wireless carriers propose to install directional panel antennas on the sides of the single -story Apple building located at 18920 Forge Drive 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: HAMMETT & EDISON, INC. T2KR.2 CONSULTING ENGINEERS SAN FRANCISCO Page I of Transmit "Uncontrolled" Occupational Limit Wireless Service Band Frequency Public Limit (5 times Public) Microwave (point-to-point) 1-80 GHz 1.0 mW/cm2 5.0 mW/cm2 Millimeter -wave 24-47 1.0 5.0 Part 15 (WiFi & other unlicensed) 2-6 1.0 5.0 BRS (Broadband Radio) 2,490 MHz 1.0 5.0 WCS (Wireless Communication) 2,305 1.0 5.0 AWS (Advanced Wireless) 2,110 1.0 5.0 PCS (Personal Communication) 1,930 1.0 5.0 Cellular 869 0.58 2.9 SMR (Specialized Mobile Radio) 854 0.57 2.85 700 MHz 716 0.48 2.4 [most restrictive frequency range] 30-300 0.20 1.0 HAMMETT & EDISON, INC. T2KR.2 CONSULTING ENGINEERS SAN FRANCISCO Page I of APPLE INC. AT&T Site No. CCL04017 18920 Forge Drive T -Mobile Site No. SF14980A Cupertino, California Verizon Site No. 519109 Proposed Base Stations 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 AT&T Mobility, T -Mobile, and Verizon Wireless, those three wireless carriers propose to install antennas high on the sides of the southwest corner of the single - story Apple building located at 18920 Forge Drive in Cupertino. Each carrier would install two antennas mounted on the south and west sides of the building, creating two groups of three consisting of one antenna from each carrier. The six antennas would be mounted at an effective height of about 19 feet above ground. The individual carriers' operating specifications are as follows: HAMMETT & EDISON, INC. T2KR.2 CONSULTING ENGINEERS SAN FRANCISCO Page 2 of 4 APPLE INC. 18920 Forge Drive Cupertino, California Proposed Base Stations AT&T AT&T Site No. CCL04017 T -Mobile Site No. SF14980A Verizon Site No. 519109 • Zoning drawings by J5 Infrastructure Partners, dated December 20, 2018 • Two Ericsson Model AIR5331 antennas • Oriented toward 180°T and 270°T • Maximum effective radiated power: 610 watts at 39 GHz T -Mobile • Two Ericsson Model AIR5121 antennas • Oriented toward 165°T and 285°T • Maximum effective radiated power: 243 watts at 28 GHz Verizon • Zoning drawings by Camp+ Associates, dated December 6, 2018 • Two Ericsson Model AIR5121 antennas • Oriented toward 165°T and 285°T • Maximum effective radiated power: 243 watts at 28 GHz Study Results For a person anywhere at ground, the maximum RF exposure level due to the cumulative operation of all three carriers is calculated to be 0.092 mW/cm2, which is 9.2% of the applicable public exposure limit. The maximum calculated level at the second -floor elevation of any nearby building* is 0.79% of the public exposure limit. 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. Recommended Mitigation Measures Due to their mounting locations and height, 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 antennas, * Including the residences located at least 200 feet away, based on photographs from Google Maps. HESANHAMMETT & EDISON, INC. T2KR.2 CONSULTING ENGINEERS FRnNCisCO Page 3 of APPLE INC. 18920 Forge Drive Cupertino, California Proposed Base Stations AT&T Site No. CCL04017 T -Mobile Site No. SF14980A Verizon Site No. 519109 including employees and contractors of the respective carriers and of the property owner. No access within 6 feet directly in front of the antennas themselves, such as might occur during certain maintenance activities high on the side of the building, should be allowed while the pertinent group of antennas is in operation, unless other measures can be demonstrated to ensure that occupational protection requirements are met. It is recommended that explanatory signst be posted at the antennas, readily visible from any angle of approach to persons who might need to work within that distance. Conclusion Based on the information and analysis above, it is the undersigned's professional opinion that operation of the proposed base stations at 18920 Forge Drive 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 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 No. E-18063, which expires 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. January 8, 2019 qR,o ESSIQNV MATy�� F No, E-10 63 w Exp 5-302019 ,k sT F�ECTR�GP\. \9TF OF CA0 Rajat Mathur, P.E. 707/996-5200 t Signs should comply with OET-65 color, symbol, and content recommendations. Contact information 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. HESANHAMMETT & EDISON, INC. T2KR.2 CONSULTING ENGINEERS FRnNCisCo Page 4 of 4 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 ("NCR -P"). 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 ANSI/IEEE 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 1 0.1 Electromainetic Fields (f is freauencv of emission in MHz Electric Magnetic Equivalent Far -Field Field Strength Field Strength Power Density (V/m) (A/m) (mW/cm2) 614 614 1.63 1.63 100 100 614 823.8/f 1.63 2.19/f 100 180/f2 1842/ f 823.8/f 4.89/ f 2.19/f 900/ f2 1801f2 61.4 27.5 0.163 0.0729 1.0 0.2 3.54�f 1.59ff 4f/106 Tf1238 f/300 f/1500 137 61.4 0.364 0.163 5.0 1.0 Occupational Exposure !/ PCS FM Public Exposure 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