Analyses of propagation characteristics in future railway communication systems using 25 GHz band radio

This paper first presents a construction of a next generation mobile communication system for future railway using the 25 GHz band, linking trains traveling at high speed with ground facilities as one vital link in such an information system. Secondly, we study the propagation characteristics of the radio links to rationalize this train communication system. We consider that the typical railway environments are distinguished by three types on analyses by complication of environments along a railway track. For each type, we calculate the propagation characteristics using a proper model. Also, we examine the influences of rain which have an important effect on the circuit quality. Computer simulation indicates that these analyses is effective to rationalize this proposed communication system.