NTT Advanced Technology Corporation (NTT-AT) was founded in 1976 as a subsidiary of NTT, the largest telecommunications service provider in Japan. Since then it has grown rapidly, largely due to its close links with NTT Laboratories and its success in the technology transfer business.
NTT has 1,100 or more Radio relay steel towers nationwide. To prevent any obstacle to communication in the radio relay antennas from heavy snow, storm, and etc., HIREC has been developed. HIREC prevents snow and ice accretion on antennas and any other equipment for 3 years in outdoor usage.