Radio waves are a mainstay of modern telecommunications. They transmit data, audio, and images, which are all essential to modern life. But what are radio waves, how are they used in telecoms, and what can you do to reduce your exposure?
What is a radio wave?
Waves are disturbances that move through a medium, transferring energy from one location to another without moving matter. Wave motion can be seen in different forms, such as in water or light. Sound waves cause air particles to vibrate back and forth, for example, while ripples on a pond cause water particles to vibrate up and down. Both can be classified according to their frequency and length.Various wave types: mechanical and electromagnetic
Although they all follow the principle of “all waves transfer energy, but they do not transfer matter”, they are part of a vast family within which categories with various physical properties can be distinguished.
- Mechanical waves: these require a material support (solid, liquid, or gas), like a stretched elastic band that oscillates or vibrates to generate mechanical waves that pass through the rubber.
- Electromagnetic waves (EM) : these can move without a material support. The electromagnetic spectrum extends from the lowest frequencies (those of power lines, for example) to the highest (UV, X-rays, gamma rays). In between are radio waves (or radio frequencies), which are naturally present and used in communications and, of course, by light: everything our eye sees is transmitted by EMs whose frequency corresponds to the “visible” band of the spectrum.
Good to know: ionizing radiation (potentially dangerous) should not be confused with non-ionizing radiation (such as radio waves). The frequency of a wave reflects the amount of energy it can carry. At very high frequencies, i.e. well above the visible spectrum, this amount of energy is so large that it can change the structure of the matter it passes through, for example, altering a molecule by releasing an electron from an atom and transforming it into an ion. This category of waves, known as “ionizing radiation” poses a health risk if exposed for a long time.
Radio waves: uses and applications in telecommunications
Radio waves are used to transmit information over long distances, modulating their amplitude or frequency. This allows data to be encoded, making wireless communication possible.
These radio waves, or radio frequencies, cover a wide band from a few kilohertz (KHz) to 300 gigahertz (GHz). They are a fundamental component of modern telecommunications, playing a critical role in various systems such as broadcasting, television, mobile telephony, Wi-Fi, navigation systems, and connected devices within the Internet of Things (IoT).
In telecommunications, radio waves are mainly transmitted through our infrastructure, especially relay antennas. They emit radio waves that allow our mobile phones to send and receive data. Mobile phones automatically reduce power to the lowest level possible to maintain a quality connection. In areas with good reception, phones operate at lower transmit power.
Limiting wave exposure therefore relies on adequate network coverage, which not only improves the quality of communications, but also minimizes RF exposure.
5G helps meet the growing need for connectivity while also improving network coverage, reducing the transmitting power of mobile devices through efficient data management.
To meet growing connectivity demands, it is essential to optimize cell towers. That’s why we work with other communications providers and mobile infrastructure operators (Towercos) including our subsidiary TOTEM to identify locations and manage sites, and even build our antennas. Cooperating in this way enables us to rationalize our infrastructure and therefore limit the visual and environmental impact.
Wave safety: regulations and framework
Regulatory controls and international recommendations are put in place by organizations such as the ICNIRP to reduce radio wave exposure and protect public health.
These are adopted on a national level and local residents are involved and/or informed in ways that are adapted to each country and culture. In France, for example, local authorities can organize public meetings between various stakeholders, including operators, for example under the leadership of ANFR or ANSES.
International and national health authorities, such as the WHO and ANSES, monitor research on the impact of radio waves and have concluded that exposure to wireless networks does not lead to adverse health effects if it is below the ICNIRP's recommended limits. IARC has classified radiofrequencies as “possibly carcinogenic” (Group 2B), stressing the need for further studies. This classification means that there is limited evidence of a possible link, but that no cause-and-effect relationship has been formally established. Further research is needed clarify the potential impact of radio frequencies on health.
Regarding exposure to radio equipment, in particular mobile phones, the Specific Absorption Rate (SAR) is limited to 2 W/kg for the head and body, and 4 W/kg for the limbs. We only sell phones that comply with current standards.
Exposure to antennas is expressed in volts per metre (V/m). Actual exposure levels are generally well below these limits, and regular measurements by independent organisations show that average exposure to waves in the environment is low.
We follow the latest research on radio waves and their health impacts and monitor our networks and equipment to ensure they comply with public health regulatory standards. We also maintain a dedicated policy and committee to ensure compliance with national and international standards and continue to invest in studies to better understand exposure to waves, especially with 5G.
Our research and compliance efforts are focused on protecting our customers and our teams.
Our technicians also follow strict protocols to keep their exposure within recommended and/or regulated levels when working on antennas and radio equipment.
Answering your questions
WHO and expert groups recommend further research on the mobile phone for three reasons. Firstly, because they consider that the hindsight available from fifteen years is insufficient. Secondly, because some studies have suggested a risk to health but they are too small in their numbers, and potential methodological bias does not permit establishing a definitive conclusion. Finally, because the mechanisms of action of electromagnetic waves on living organisms need further study.
These devices are designed to improve the use of mobile terminals in everyday life, they are very low power – around a few tens of milliwatts (mW). As indicated in WHO Fact Sheet No. 304 published in May 2006: “there is no convincing scientific evidence of possible adverse effects from base stationsand wireless networks for health”.
Furthermore, the proximity of a Femto box guarantees perfect indoor reception for a mobile (inside the home). In this way the power control in the mobile can play its role to the full and, in this case, it functions at much lower levels than its maximal power. Exposure due to the mobile is reduced by a similar ratio.