This IDC Market Note discusses the evolution of smart railway systems toward the next generation. It has been 21 years since the first smart railway communications system, GSM-Railway (GSM-R), was commercialized. In the ensuing year, several key train control systems have been developed: the European Train Control System (ETCS) and Communications-Based Train Control (CBTC) for main lines and urban railways, respectively. A train control system utilizes an array of sensors to manage operations, enhance safety, and improve operational efficiencies. However, the industry has to use a combination of fiber and various wireless communications technologies along tracks. With the advent of 5G and the Future Railway Mobile Communications System (FRMCS), the path to a more advanced, low-latency, and high-bandwidth infrastructure is becoming clearer, and the industry is busy carrying out proof of concepts (POCs) and conducting radio channel studies to understand the radio propagation characteristics of high-speed rail and determine the optimal frequencies for an infrastructure that will essentially be a private network in the edge.