Providing current and future cellular services to high speed trains

The demand for a broadband wireless connection is nowadays no longer limited to stationary situations, but also required while traveling. Therefore, there exist combined efforts to also provide wireless access on high speed trains (HSTs), in order to add to the attractiveness of this means of transportation. Installing an additional relay on the train, to facilitate communication, is an approach that has already been extensively discussed in the literature. The possibility of a direct communication between the base station and the passenger has been neglected until now, despite it having numerous advantages. Therefore, a comparison between these two opposing approaches is presented in this article, accompanied by a detailed discussion of the related aspects. Additionally, we present simulation results for the two approaches when applying different schemes to supply a wireless connection. We also discuss the presented results from the perspectives of mobile operators and train operators.