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HomeMy WebLinkAboutJ_ATT RF Letter and Coverage Maps_Crown Castle_210602_v1.pdfSD2453 Sunset Relo FA 14912126 RF Justification Coverage Justification OVERVIEW AT&T is proposing to build a new wireless communication facility (“WCF”), SD2453 Sunset, located at a specific location (LAT: 47°30' 13.92" LONG: 122°10' 49.94" W) in Renton. This will provide service improvement along stretch of NE Sunset Blvd, between 405 and Union Ave. This will further consolidate indoor coverage at the same time. This proposed WCF is also part of a significant, state-wide initiative by AT&T to upgrade existing wireless sites and to build new sites, including in rural area with less coverage, to support the FirstNet Network and deploy the new frequencyband (“Band 14”). SEARCH RING AT&T’s radio frequency (“RF”) engineers performed an RF engineering study, considering multiple objectives, to determine the approximate site location and antenna height required to fulfill the noted network objectives for the targeted service area. From this study, AT&T’s RF engineers identified a “search ring” area where a WCF may be located to provide effective service in the target coverage area. Figure A—Targeted Search Ring 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. Coverage Justification—Con’t COVERAGE OBJECTIVE 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 blue triangle 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 areas not shaded in green. Currently, the target coverage area has minimal to no 4G voice service and does not have adequate4G LTE service. Figure C.1—Projected New AT&T Coverage identifies the projected coverage from the proposed new WCF with the requested antenna RAD height of 114 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 reliably used to make and receive telephone calls and use data service in the presence of varying signals. Figure C.2—Projected New AT&T Coverage identifies the projected coverage from the proposed new WCF with the requestedantenna RAD height of 95 ft. Figure D —Coverage comparison with RAD at 114ft vs 95 ft With RAD at 114ft it is able to provide 1.42 sq-mile new coverage. At the same time with RAD at 95ft it provides 1.10 sq-mile new coverage. It would be 22.60% of coverage reduction when RAD goes from 114ft to 95ft. ANTENNAS AND EQUIPMENT To meet the above coverage objectives, this proposed site will contain up to 12 panel antenna, 18 RRH units and 2 SQUIDS (together with all associated accessory equipment). Figure A—Targeted Search Ring Figure B —Existing AT&T Coverage Targeted Service Area BEFORE Addition of Proposed New Wireless Facility 0.4mi.0.2mi.0.4mi. 0.4mi.0.2mi.0.4mi. Figure C.1—Projected New AT&T Coverage Coverage with Proposed AT&T Facility On-Air—114 ft Antenna Rad Center Figure C.2—Projected New AT&T Coverage Coverage with Proposed AT&T Facility On-Air—95 ft Antenna Rad Center 0.4mi.0.2mi.0.4mi. Figure D — Coverage Comparison @ 114’ vs. 95’ 0.4mi.0.2mi. 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 700 MHz to 850 MHz range, the radio signals will travel further and will penetrate buildings better than the radio frequencies in the 1900 MHz-2300 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. 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.