Wireless communication technologies play an essential role in supporting railway operation and control. The current Global System for Mobile Communications-Railway (GSM-R) system offers a rich set of voice services and data services related with train control, but it has very limited multimedia service bearer capability. With the development of commercial wireless industry, Long-Term Evolution (LTE) mobile broadband technology is becoming the prevalent technology in most of commercial mo-bile networks. LTE is also a promising technology of future railway mobile communica-tion systems. The 3rd Generation Partner Project (3GPP) and China Communications Standards Association (CCSA) have proposed two feasible LTE based broadband trunk-ing communication solutions: the 3GPP Mission Critical Push to Talk (MCPTT) solu-tion and B-TrunC solution. In this paper, we first introduce the development of railway mobile communications and LTE technology. The user requirements of future railway mobile communication system (FRMCS) are then discussed. We also analyze the suit-ability of the two LTE-based solutions for LTE based Next-Generation Railway Mobile Communication System (LTE-R) from different aspects.