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21-101703-RF Justification-ATTCH 3-SC2064 Redondo Beach-04-28-21-V1 03/30/2021 City of Federal Way Permits Department 33325 8th Ave S Federal Way, WA 98003 Re: AT&T’s Radio Frequency (RF) Engineering Justification for the Proposed Wireless Communications Facility in Pierce County: AT&T SITE SC2064 Redondo Beach at 29601 8th Ave SW Federal Way, WA 98023 / 47.336241, -122.345134 To Whom It May Concern, Enclosed please find the RF Justification document prepared for AT&T’s proposed new wireless communications facility at the above noted location. This letter serves as my verification, to the best of my knowledge, of the accuracy of the RF information, propagation maps, and analysis provided in the attached RF Justification. Thank you for your consideration of this information. Sincerely, Kung-Liang Brian Lin RF Engineer AT&T Mobility SC2064 Redondo Beach RF Justification SERVICE OBJECTIVES & TARGETED SERVICE AREA AT&T is proposing to build a new wireless communication facility (“WCF” and/or “Facility SC2064 Redondo Beach, at 29601 8 th Ave SW in Federal way, WA. Service Objectives—Generally AT&T strives for a network design that provides high radio frequency (“RF”) signal strength and signal-to-interference-plus- noise ratio (“SINR”) resulting in quality service inside buildings and vehicles. To support this network design there are two main drivers that prompt the need for a new cell site—coverage and capacity. “Coverage” is the need to expand wireless service into an area that either has no service or bad service. “Capacity” is the need for more wireless resources. Cell sites have a limited amount of resources to handle voice calls, data connections, and data volume. When these capacity limits are reached, user experience quickly degrades. Capacity issues for LTE networks are identified by using SINR metrics to measure the network’s signal quality when there is a high traffic load condition. High traffic areas in the network experience poor SINR due to the increased amount of signal noise/interference generated by the interferingstrengthof the simultaneous transmissions. Service Objectives—ProposedNew Facility The proposed new Facility is a service coverage replacement site. Currently, portions in and around Adelaide & Redondo have minimal to no 4G voice service and AT&T’s existing coverage in the area is at or near its capacity and is insufficient for the volume of traffic (i.e. though this area already has AT&T coverage, additional capacity is needed to service the volume of users). The objective of this site is to provide dominant coverage to residential houses within Redondo, Buena and Adelaide. The new Site will also provide coverage to Redondo Beach Dr S and other minor roads in the neighborhood. This service objective and Targeted Service Area was determined by AT&T’s RF engineers through a combined analysis of market demand, customer complaints, service requests, and RF engineering design (including SINR metrics). The proposed new Facility meets AT&T’s service objectives to provide sufficient continuous and uninterrupted outdoor, in- vehicle, and in-building wireless service within the Targeted Service Area, resulting in fewer dropped calls, improved call quality, and improved access to additional wireless services the public now demands (this includes emergency 911 calls). SEARCH RING AT&T’s RF engineers performed an RF engineering study—considering multiple objectives—to determine the approximate site location and antenna height required to best fulfill the noted service objectives within the Targeted Service Area. From this study, AT&T’s RF engineers identified a “search ring” area where a new wireless facility may be located to provide effective service in the Targeted Service Area. As this is a service coverage replacement site intended to improve Redondo, Buena and Adelaide, the proposed new Facility must be located within the identified search ring to be able to establish a dominant signal within the Targeted Service Area—i.e. the proposed new Facility will provide service to users’ handsets and prevent them from communicating with AT&T’s existing facility, therebyrelievingsome of the burdenon the existing facility by offloadingusers’ data requirements to the proposed new Facility. Figure A—Targeted Search Ring, below, indicates the search ring AT&T’s RF engineers established for this proposed site. A discussion of the methodology AT&T’s RF engineers used to identify the search ring is included at the end of this RF Justification document. Figure A—Targeted Search Ring PROPOSED NEW AT&T FACILITY Antennas and Equipment To meet AT&T’s service objectives within the Targeted Service Area, AT&T is proposing to install up to twelve (12) eight foot (8ft) panel antennas and twelve (18) remote radio head (RRH) units, together with all associated equipment with an 55ft antenna tip height. Required Height As the proposed new Facility is intended to provide new coverage and enhance existing capacity, height and location play an important role. The proposed antenna tip height was determined by considering various factors such as the height of surrounding wireless sites, ground elevation, obstructions to the signal, and the surrounding terrain. Accordingly, the proposed 55ft antenna tip height is the minimum necessary to best meet AT&T’s service objectives within the Targeted Service Area. A lower antenna tip height at this location would not provide as effective capacity improvement within the Targeted Service Area as compared to the 55ft antenna tip height. The proposed antenna tip height is also the height where an AT&T wireless device can be reliably used to make and receive telephone calls and use data service in the presence of varying signals. Projected New Coverage Based upon the above proposed equipment and antenna tip height, AT&T’s RF engineers project that the proposed Facility will provide the following new AT&T coverage. Figure B—Existing AT&T Coverage shows existing AT&T wireless services in the general area of the proposed new site, which demonstrates the current gap in coverage in the targeted service area. The red star indicates the location of the proposed new WCF. The pink diamond indicates the location of existing AT&T WCF sites; coverage from AT&T’s existing WCF sites is shaded in green. As can be seen, there is a coverage gap in all areas not shaded in green. Currently, the target coverage area has minimal to no 4G voice service and does not have adequate 4G LTE service. Figure C—Projected New AT&T Coverage identifies the projected coverage from the proposed new WCF with the requested antenna tip height of 55 ft. The proposed antenna tip height is the minimum necessary to help fill the coverage gap relative to nearby complementary wireless facilities and to support the FirstNet Network. This is also the height where an AT&T wireless device can be reliablyused to make and receive telephone calls and use data service in the presence of varyingsignals. Figure B—Existing AT&T Coverage Targeted Service Area BEFORE Addition of Proposed New Wireless Facility Figure C—Projected New AT&T Coverage Coverage AFTER Proposed AT&T Facility On-Air—55ft Antenna Tip Height Alternative Site Analysis There are no alternative site locations within the targeted search ring as possible locations for the proposed new WCF. Search Ring Methodology AT&T’s RF engineers used coverage propagation software systems to predict the coverage provided by the proposed new WCF. The software and AT&T’s RF engineers considered the general factors outlined below, as well as more project- specific factors such as the type of antenna, antenna tilt, etc. Coverage.The antenna site must be located in an area where the radio frequency broadcasts will provide adequate coverage within the targeted service area. The RF engineer must take into consideration the coverage objectives for the site as well as the terrain in and around the area to be covered. Because radio frequency broadcasts travel in a straight line and diminish as they travel further away from the antennas, it is generally best to place an antenna site near the center of the desired coverage area. However, in certain cases, the search ring may be located away from the center of the desired coverage area due to the existing coverage, the surrounding terrain, or other features which might affect the radio frequency broadcasts, e.g. buildings or sources of electrical interference. Clutter.AT&T’s WCFs must “clear the clutter”—the WCF site must be installed above or close to RF obstructions (the “clutter”) to enable the RF to extend beyond and clear the clutter. AT&T’s radio frequencies do not penetrate mountains, hills, rocks, or metal, and are diminished by trees, brick and wood walls, and other structures. Accordingly, AT&T’s antennas must be installed above or close to the “clutter” to provide high quality communications services in the desired coverage areas. Additionally, if the local code requires us to accommodate additional carriers on the support structure, the structure must be even taller to also allow the other carriers’ antennas to clear the clutter. Call Handoff.The WCF site must be in an area where the radio broadcasts from the site will allow seamless “call handoff” with adjacent WCF sites. Call handoff is a feature of a wireless communications system that allows an ongoing telephone conversation to continue uninterrupted as the user travels from the coverage area of one antenna site into the coverage area of an adjacent antenna site. This requires coverage overlap for a sufficient distance and/or period of time to support the mechanism of the call handoff. Quality of Service.Users of wireless communications services want to use their services where they live, work, commute and play, including when they are indoors. AT&T’s coverage objectives include the ability to provide indoor coverage in areas where there are residences, businesses and indoor recreational facilities. Search Ring Methodology—Con’t Radio Frequencies used by System.The designs of wireless communications systems vary greatly based upon the radio frequencies that are used by the carrier. If the carrier uses radio frequencies in the 850 MHz to 950 MHz range, the radio signals will travel further and will penetrate buildings better than the radio frequencies in the 1900 MHz band. As a result, wireless communications systems that use lower radio frequencies will need fewer sites than wireless communications systems that use higher radio frequencies. AT&T’s system uses only frequencies in the 1900 MHz so AT&T’s system requires more sites in order to achieve the same coverage that is provided by the carriers which use the 850 MHz to 950 MHz frequency band. Land Use Classifications.A&T’s ability to construct a WCF site on any particular property is affected by state and local regulations, including zoning and comprehensive plan classifications, goals, and policies. AT&T’s search rings take these laws and regulations into consideration.