What are radio waves? Safety of Radio Waves

Properties and roles of radio waves

Radio waves are "electromagnetic waves" that propagate through space while electric and magnetic fields interact with each other. Electromagnetic waves have wave properties, and the number of times a wave vibrates per second is called its frequency. Radio waves are defined as "electromagnetic waves with a frequency of 3 million MHz (megahertz) or less."

Radio waves are used in a wide range of applications, including television and radio broadcasting, communications such as mobile phones and smartphones, microwave ovens, fluorescent lights, medical equipment such as MRI machines, ETC systems, wireless IC card automatic ticket gates, weather radar, and GPS.

A chart classifying electromagnetic waves by frequency. This diagram explains the types of electromagnetic waves (radio waves, infrared rays, visible light, ultraviolet rays, X-rays, etc.), their relationship to frequency and wavelength, and their main applications (radio, television, mobile phones, satellite broadcasting, etc.).
Source of the chart: Excerpted from "Radio Waves and Safe Living" by the Ministry of Internal Affairs and Communications.

The characteristics of radio waves can be summarized as follows:

Overview of the principles of radio wave generation, properties, and uses
Radio waves in nature Radio waves exist in nature and are generated by lightning and frictional electric spark discharges.
Properties of Radio Waves Radio waves are waves that have frequencies, are subject to reflection and refraction, and their strength weakens as they move away from the transmitting antenna.
Use of radio waves Radio waves are used for a variety of purposes, not just broadcasting and communications.

National Initiatives Regarding Radio Waves in Japan

In Japan, based on research findings from both domestic and international sources spanning over 50 years, "Radio Wave Protection Guidelines" have been established, and regulations in accordance with these guidelines have been implemented.

The Radio Wave Protection Guidelines outline the basic principles for determining whether radio waves are safe and do not affect the human body, as well as the standards based on these principles, and introduce regulations based on these guidelines. Furthermore, the standards in Japan's Radio Wave Protection Guidelines are equivalent to those of international guidelines. Since satisfying the Radio Wave Protection Guidelines is a mandatory condition for radio wave transmission operators (radio stations) to be granted licenses by the government, all radio stations undergo government checks and transmit radio waves while ensuring public safety.

Reference: Ministry of Internal Affairs and Communications website

Regarding radio waves transmitted from TOKYO SKYTREE

At TOKYO SKYTREE, radio stations for broadcasting and communications are installed after confirming that they meet radio wave protection guidelines (and are licensed by the government). This website periodically measures the radio wave environment around TOKYO SKYTREE and publishes the measurement results after the first official broadcast and operation from TOKYO SKYTREE has commenced.

Radio wave environment measurement around TOKYO SKYTREE

Start status of regular broadcasting

1

Taxi radio (Kanto Automobile Radio Association)

  • Partial operation started in March 2012
  • April 2012 Start of operation
2

Multimedia Broadcasting
(Japan Mobile Casting)

  • April 1, 2012: First broadcast
  • Broadcast ended on June 30, 2016.
3

FM radio (NHK, J-WAVE)

  • April 23, 2012: First broadcast
4

TOKYO MX

  • Simulcasting began on October 1, 2012 (broadcast from both Tokyo Tower and TOKYO SKYTREE).
  • May 13, 2013: Transmission point relocation completed (broadcasts will now only be from TOKYO SKYTREE).
5

Six Tokyo-based TV companies
(NHK, Nippon Television, TV Asahi, TBS Television, TV Tokyo, Fuji Television)

  • Broadcast begins May 31, 2013
6

Three Tokyo-based AM radio stations and FM complementary broadcasting (TBS Radio, Nippon Cultural Broadcasting, Nippon Broadcasting System)

  • Broadcast begins December 7, 2015