Wireless Search Area Feasibility Report (SAR)
The Wireless Search Area Feasibility Report (SAR) is the first published collection of due diligence information for a search area assignment. The SAR includes brief documentation of three to five qualified candidate sites as well as a summary of the overall conditions present in the search area. Completing the SAR follows from the due diligence findings collected, affecting site selection criteria as discussed in Module 8 Search Area Mapping; Module 9 Zone-ability; Module 10 Constructability; and Module 11 Lease-ability. A multi-dimensional nature of wireless site selection is that each of these criteria can positively or negatively impact one or more of the other criteria for a given site. SARs document the most eligible sites with respect to all criteria.
The initial due diligence needs for RF suitability can be satisfied by a set of coordinates (latitude and longitude), the ground elevation, a mark on a topographical map, and photos from a proposed site looking outward (to confirm the absence of obstacles to radio transmission, also known as signal propagation). This is enough for a computer simulation to determine how a given location might fulfill its coverage objective. Field observations supplement computer models. RF engineers will propose an antenna level AGL. For existing structures, RF engineers will need to know the available antenna elevations.
It is also beneficial to make notes in the SAR of surrounding airports and nearby AM radio stations (using the AM Compliance Tool at https://www.lbagroup.com). Zoning regulations, such as direct limitations on structure height or the effect of setback regulations on structure height, directly link RF suitability and zone-ability. This is one example of how the criteria elements of a SAR directly affect one another.
Collocation is favored by local jurisdictions. Local code incentives often offer a streamlined process for collocations on existing structures, such as approval upon completion of an administrative review or issuance of a building permit without the need for hearings. Assess the jurisdiction’s cooperativeness to comply with any existing federal and state laws imposing limitations on local regulation of macrocell and microcell site facilities1, as discussed in Module 9 Zone-ability. Below are considerations to evaluate in the characterization of alternate site candidates and determination of the order in which the candidates are presented in the SAR.
Regarding constructability, the construction manager needs to analyze what it will cost to build each site proposed in the SAR. Factors affecting site construction costs include the slope of the terrain, the soil content of the ground, and the need for a road culvert to cross a ditch from the public right-of-way to private land. A retaining wall may be necessary to compensate for steep terrain. Soil content affects the foundation design for the facility. These additions need to be included in the budget.
Accessibility is the major criterion affecting constructability. The question of property access applies to utilities as well as for personnel and vehicles. Data relevant to accessibility include the site location by address, including the city, state, zip code, and county. Where no address is assigned to a property, it’s common to reference the distance and direction from a road intersection or a town. A set of directions is provided by the site acquisition consultant for each candidate from a starting point designated by the developer or client, such as a company office, a landmark, or the exit of an interstate highway.
The availability of a property is a prerequisite for submitting a candidate for consideration in the SAR. The form for each SAR candidate includes spaces to insert the property owner’s name and contact information, the rent agreed to by the property owner, what size lease area will be available for the site, and any relevant comments about the property ownership conversations that may impact site selection positively or negatively. Site developers typically look to secure a site sized 209′ × 209′ (an acre) or 100′ × 100′ whenever possible. Smaller sites are acceptable where local development is contentious. In rural areas where guyed towers are planned, additional space is necessary to include guy anchor locations. The wireless facility developer or its A&E firm advises the consultant as to the absolute minimum space required. Regarding collocation on existing communications structures, the SAR needs to identify what elevations are available on a rental structure to match the RF engineer’s needs.
SAR Cover Sheet
The cover sheet of the SAR is intended to summarize the contents of the report including a list of the candidate sites (named and numbered), a list of the maps used for reference, the project reference number and name, the date of submittal, contact information to reach the consultant who prepared the report, and a concise summary of the search area characteristics and each individual candidate. The cover sheet can also briefly list factors that impact the whole search area as well as cost factors that may vary among candidates such as distances to power, local telephone transport, fiber-optics transport, and public rights-of-way. Considering that a SAR’s length including photos is typically fifteen to eighteen pages, it’s helpful to number the pages and include an index of page numbers on the cover sheet for easy access to parts of the document.
It’s important to use maps in the SAR to characterize where the candidate sites are located in the search area with respect to each other, local streets, county roads, state highways, federal highways, and area topography. This is typically accomplished with two or three maps and an aerial photo or satellite imagery.