For a railway vehicle communication device

A railway-train communication apparatus provided in a railway train secures the adaptability to a transmission path having low signal quality and improves the certainty of data transmission. The railway-train communication apparatus includes a node device 21, which includes converters 31-1 and 31-2 that perform a mutual signal conversion between an HDLC signal flowing through an inter-car network constructed between cars of the railway train and an Ethernet (registered trademark) signal flowing through an in-car network constructed in each of the cars and switching hubs 32 arranged between the converters 31-1 and 31-2 and for respectively connecting the converters 31-1 and 31-2, and network controllers 22-1 and 22-2 that are connected to the switching hubs 32.