Modern railbound traffic has the need for a communication system between traffic control center and every single train, being on the line at the time. High data rate transmission and high selectivity of orientation should be inherent. This can be done, using 35 GHz lineof-sight transmission links. In order to investigate the various influences of the railway environment, propagation measurements along different railway lines have been carried out. According to the test conditions secure transmission can be achieved for distances, ranging from 500 to 2000 m.Introduction: The successful employment of mm-wave technology for various applications in traffic and industry