A study on the radio coverage in underground stations of the new copenhagen metro system

In connection with the extension of the Copenhagen Metro system, architects and wireless operators met early in the design phase to plan the radio coverage inside the public areas of the metro transport system. Based on common best practice, an initial design for the antenna installations, and hence radio coverage, was proposed for a distributed antenna system in each of two distinctly different types of underground stations. In this paper, we describe the considerations for the design, and specifically the modelling and analysis of the underground stations by way of a commercial ray-tracing tool. Radio coverage results are given for different designs, including different number and types of antennas, their configuration and placement, as well as the dependency on frequency and construction materials and presence of trains on the station platforms. In a practical case like this, compromises between stakeholders impact to the design and in some cases rule out options with better, more uniform, radio coverage. Also, given the constraints of the problem, common best practice leads to a conservative design. It shows a good margin for uncertainties and unaccounted propagation phenomena by an analytical comparison.