The demand for high-speed data access to railway infrastructure and internet broadband data in railway is increasing due to the high density of the trains and passengers. Currently, communication access in trains is based on radio frequency (RF) wireless access networks that are slow and insufficient for the demands of the high-speed railway (HSR) and its customers. However, performance, service attributes, frequency band, and industrial support should be considered for the selection of a suitable communication system that can fulfill the requirements of HSR operation. This paper investigates overhead line equipment (OLE) as access network connecting trains to the backbone communication networks. The ABCD transmission model is used to represent the transfer function of the OLE channel. It was shown that transmission over OLE is affected by the frequency and link distance. The simulation results also show that the channel gain of the OLE channel attenuated faster at higher speeds compared to train movement at lower speeds.