HIREC Case Studies / Countermeasure against Snow Accretion on Antennas for Mobile Carriers

HIREC: Super Hydrophobic Coating for Antenna, Radome and Other Public Infrastructure


Snow Accumulation Cause Mobile Service Outages

One of the world’s leading mobile communications companies was experiencing service outages due to blizzards in the northern part of Japan. HIREC solved the problem.

Mobile Service Outages and Its Counter Measurements

NTT DOCOMO(*), one of the world’s leading mobile communications companies, had experienced its service outages across a wide area in the north of Japan. It was caused by snow accumulation on the surface of antennas, disrupting signal transmission. In response to the problem, NTT DOCOMO immediately looked for the solution, and found the super hydrophobic material, HIREC.

HIREC Solves the Snow Accumulation Problems

HIREC has super-high water repellency and a photocatalytic self-cleaning mechanism. Water droplets do not stick to any HIREC coated surface, thus prevents not only accumulating snow but also forming water film. In addition to the HIREC’s photocatalytic self-cleaning was especially suitable for NTT DOCOMO which has a service area around the Sea of Japan: yellow sand from China gets blown in by wind and sticks to the antennas.

A surface coated with HIREC exfoliates and dissolves dirt by a sunlight activated photocatalyst, which then creates a clean new super hydrophobic surface. HIREC does not interfere with the signal even at high frequency bands 11 up to 22 GHz.

“After applying HIREC on the antennas, disruption of the line had never been observed. It’s 0%,” said Mr. Satoshi Saito, an  NTT DOCOMO engineer. He believes that if it is possible for any wireless provider to keep service stable even in the event of heavy snow or rainfall by applying HIREC, it will definitely be an advantage over competitors.

Mr. Saito said that in today’s situation, failure of the cell phone service is unacceptable 24 hours a day, 365 days a year.


NTT DOCOMO has more than 250 HIREC coated antennas in the center and northern area of Japan.
NTT DOCOMO asked its antenna manufactures to apply HIREC on new antennas at the factory prior to shipping.


HIREC is a valid countermeasure for the snow accretion problems.