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CCL04410 RF Compliance Report 10172023 AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 Statement of Hammett & Edison, Inc., Consulting Engineers The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of 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 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 Standard 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 HEHAMMETT&EDISON,INC. CONSULTING ENGINEERS LOAY snw FRANCISCO ©2023 Page 1 of 3 AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 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 October 10, 2023, a non-holiday weekday. AT&T had installed ten directional panel antennas behind the 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. Boundary lines in blue and yellow had been painted on the roof to indicate the possible presence of RF fields exceeding the public and occupational limits, respectively. Explanatory signs* had been posted at the roof access door, 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 T-Mobile and Verizon Wireless; the antennas formerly used by Sprint had been removed. Measurement Results The measurement equipment used was a Narda Type NBM-520 Broadband Field Meter with Type EA-5091 and EF-6092 Isotropic Electric Field Probes (Serial Nos. 01291 and C-0223, respectively). The meter and probes were under current calibration. The maximum RF exposure level measured on the roof of the building outside the blue boundary lines was 30% of the applicable public limit; levels exceeding the occupational limit did not extend beyond the yellow boundary lines. The maximum observed power density level for a person at ground near the site was 0.0033 mW/cm2, which is 1.65% 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. * Signs complied with OET-65 color and symbol recommendations. Contact information was provided to arrange for access to restricted areas. HEHAMMETT&EDISON,INC. CONSULTING ENGINEERS LOAY SAN FRANCISco ©2023 Page 2 of 3 AT&T Mobility • Base Station No. CCL04410 10335 North Tantau Avenue • Cupertino, California FA No. 14290836, USID No. 192687 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. 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, 2025. 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. 19 'ESS/ C E-1 3026 �_►L William F. Han iett P.E. M-20676 ' WFn 707/996-5200 Ct Exp.6-30-2025 October 17, 2023 �. # ,Q CHAWVG " OF CA�1F HAMMETT&EDISON,INC. LOAY CONSULTING ENGINEERS SANFRANCISCO c2023 Page 3 of 3 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 IEEE C95.1-2019, "Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz 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 Electric Magnetic Equivalent Far-Field Range Field Strength Field Strength Power Density (MHz) (V/m) (A/m) (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/f z 180/f z 30— 300 61.4 27.5 0.163 0.0729 1.0 0.2 300— 1,500 3.54�f 1.59ff 4f/106 Tf1238 f/300 f11500 1,500— 100,000 137 61.4 0.364 0.163 5.0 1.0 1000 � Occupational Exposure 100 PCs o10 FM Cell 0.1 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. Hammett & Edison has incorporated conservative calculation formulas in the FCC Office of Engineering and Technology Bulletin No. 65 (August 1997) for projecting field levels in a computer program capable of calculating, at thousands of locations on an arbitrary grid, the total expected power density from any number of individual radio frequency sources. The program allows for the inclusion of uneven terrain in the vicinity, as well as any number of nearby buildings of varying heights, to obtain more accurate projections. HAMMETT&EDISON,INC. CONSULTING ENGINEERS FCC Guidelines , SANFRANCISCO ©2023 Figure 1