Simulation, accuracy and design of radio coverage in confined environment with a dominant path prediction tool

The design of radio systems for the retransmission of signals FM, UHF and VHF in confined spaces(tunnels, buildings, parking garages..) requires a precise modeling of electromagnetic propagation such that to reduce to the minimum necessary the installation operations of hardware and software con guration. During the initial phase of a project, once acquired geometric information such as arrangement of buildings and the hydrography of the soil and the properties of materials used, is possible to make an electromagnetic simulation so as to plan the layout of the radio antennas of the territory. The signal propagation is complex since it is almost never possible to guarantee the visibility of radio antennas involved. Compared to the condition of free space, i.e. the absence of obstacles, where the signal is attenuated in inverse proportion to the distance, the attenuation depends on the location and on the presence of obstructions in the path and multipath(echoes or replicas of the transmitted signal). Given the complexity of the problem, the simulation results show unavoidable approximations. The objective of this work is to review the operation of a dominant path simulation software and validate the software comparing the simulation results with the measurements performed on a real site and with other more classical models for propagation prediction, including the ray tracing technique. The accuracy achieved in two diff erent propagation environments such as indoor and tunnel is good and compared to the ray tracing model the computation time results highly reduced. Once the software is validated, a study of a new wireless project has been created.