{'fraction_non_alphanumeric': 0.017341040462427744, 'fraction_numerical': 0.0, 'mean_word_length': 5.723300970873787, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Propagation experiment on millimeter wave for high-speed rail trains

Many kinds of radio communication systems are utilized for train operations and passenger services in railway. In recent years, aiming furthermore advancement of safety and stability or improvement of service quality, developments of large capacity radio communication have been actively promoted in various fields. Millimeter wave communications had been examined for application to Shinkansen train (high-speed rail system in Japan) radio since the period of Japan National Railways. However, there were some problems on the cost aspect, for example, a lot of expensive radio transceivers were required in the technology of the day. Recently, it becomes possible to construct radio systems at low cost in association with performance enhancement and price reduction of semiconductor devices, application of RoF (Radio on fiber) technique and convergence with existing radio communication systems. Therefore millimeter communication systems will be expected to precede in future railway. In this paper, current situations of millimeter wave communications are introduced firstly. Then, we report the experimental results and future feasibilities through propagation tests conducted using actual rolling stock and maintenance car on Shinkansen tracks, aiming to obtain fundamental data for the radio system design.