Explanation
According to the 5G Site Survey Guide (V1.0) (PDF)-EN, the engineering file is not a material that needs to be prepared before site survey. The engineering file is a document that records the site survey results and the design plan for the site. The engineering file is generated after the site survey is completed and approved by the customer. The materials that need to be prepared before site survey are:
Local map: A map of the area where the site is located, showing the roads, buildings, landmarks, and other features. The local map helps the site survey team to plan the route, identify the site location, and evaluate the surrounding environment.
Site survey table: A table that lists the items and parameters that need to be checked and measured during the site survey, such as antenna installation space, equipment room space and load bearing capacity, power supply, grounding, lightning protection, cable routing, etc. The site survey table helps the site survey team to conduct a comprehensive and systematic inspection of the site conditions and record the data.
5G antenna height table: A table that shows the recommended antenna height for different scenarios and frequency bands based on empirical data and theoretical calculations. The 5G antenna height table helps the site survey team to determine the optimal antenna installation height for achieving the best coverage and performance.
Therefore, the correct answer is D.