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CCL04410 RF Compliance Report 11202020AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 A2JI Page 1 of 3 ©2020 Statement of Hammett & Edison, Inc., Consulting Engineers The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained by AT&T Mobility, a wireless telecommunications carrier, to evaluate its existing base station (Site No. CCL04410) located at 10335 North Tantau Avenue in Cupertino, California, for compliance with appropriate guidelines limiting human exposure to radio frequency (“RF”) electromagnetic fields. Executive Summary AT&T had installed directional panel antennas behind the existing view screen wall above the roof of the four-story Apple office building located at 10335 North Tantau Avenue in Cupertino. All exposure levels under the existing conditions for anyone in publicly accessible areas nearby, together with the operation of the other carriers at the site, were well below the federal standard. 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 wireless services are as follows: 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 CBRS (Citizens Broadband Radio) 3,550 MHz 1.0 5.0 BRS (Broadband Radio) 2,490 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 2.4 600 MHz 617 0.41 2.05 [most restrictive frequency range] 30–300 0.20 1.0 AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 A2JI Page 2 of 3 ©2020 General Facility Requirements Antennas for base station use are designed to concentrate their energy toward the horizon, with very little energy wasted toward the sky or the ground. Since the antennas need an unobstructed area in front of them, it is generally not possible for exposure conditions to approach the FCC limits without being physically very near the antennas. Site Description The site at 10335 North Tantau Avenue in Cupertino was visited by Mr. Scott Walthard, a qualified field technician employed by Hammett & Edison, Inc., during normal business hours on November 12, 2020, a non-holiday weekday. AT&T had installed eight directional panel antennas behind the existing view screen wall above the roof of the four-story office building located at that address. Access to the antennas was restricted by their mounting locations. Explanatory signs* had been posted at the access doors in the view screen and on the view screen wall in front of the antennas. Similar antennas were observed on the same building for use by Sprint, T-Mobile, and Verizon Wireless, other wireless telecommunications carriers. Measurement Results The measurement equipment used was a Wandel & Goltermann Type EMR-300 Radiation Meter with Type 18 and 25 Isotropic Electric Field Probes (Serial Nos. F-0034 and E-0001, respectively). The meter and probes were under current calibration by the manufacturer. The maximum RF exposure level on the roof of the building was 85% of the applicable public limit. The maximum observed power density level for a person at ground near the site was 0.0015 mW/cm2, which is 0.75% of the most restrictive public limit. The three-dimensional perimeter of RF levels equal to the public exposure limit did not reach any publicly accessible areas. Recommended Training Due to their mounting locations and height, requiring passage through a locked door to reach the roof, the carriers’ antennas were not accessible to the general public, and so no additional mitigation measures are necessary to comply with the FCC public exposure guidelines. In addition to the access restrictions and signs already in place, 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 carriers and of Apple. * Signs complied with OET-65 color and symbol recommendations. Contact information was provided to arrange for access to restricted areas. AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 A2JI Page 3 of 3 ©2020 Conclusion Based on the information and analysis above, it is the undersigned’s professional opinion that the AT&T Mobility base station located at 10335 North Tantau Avenue in Cupertino, California, as installed and operating at the time of the visit, complies with the FCC guidelines limiting public exposure to radio frequency energy and, therefore, does not for this reason cause a significant impact on the environment. 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, 2021. 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. _____________________________________ William F. Hammett, P.E. 707/996-5200 November 20, 2020 FCC Radio Frequency Protection Guide FCC Guidelines Figure 1 1000 100 10 1 0.1 0.1 1 10 100 103 104 105 Occupational Exposure Public Exposure PCS CellFM PowerDensity(mW/cm2)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 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 Electromagnetic Fields (f is frequency of emission in MHz) Applicable Range (MHz) Electric Field Strength (V/m) Magnetic Field Strength (A/m) Equivalent Far-Field Power Density (mW/cm2) 0.3 – 1.34 614 614 1.63 1.63 100 100 1.34 – 3.0 614 823.8/ f 1.63 2.19/ f 100 180/ f2 3.0 – 30 1842/ f 823.8/ f 4.89/ f 2.19/ f 900/ f2 180/ f2 30 – 300 61.4 27.5 0.163 0.0729 1.0 0.2 300 – 1,500 3.54 f 1.59 f f /106 f /238 f/300 f/1500 1,500 – 100,000 137 61.4 0.364 0.163 5.0 1.0 Frequency (MHz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©