Determination of percentage of linear coverage area in railways

Railway communications have recently attracted much interest. In the last few years, most of the literature focus on the propagation issues for link budget. However, the railway coverage is different from the cellular radio systems. It is well-known that due to effect of shadow fading, some locations within a coverage area will have a received signal below a particular threshold. Computing how the boundary coverage relates to the overall percentage of coverage area is very useful for the link budget. While this problem has been well solved for the circular coverage of cellular systems, there is a lack of the determination of percentage of coverage area in the narrow-strip-shaped railway cells, i.e., the linear coverage. It is of interest to determine the percent of locations within a linear rail track in which the received signal strength from a radiating base station antenna exceeds a particular threshold.