5G Networks


Deployment of 5G goes hand in hand with gaining the public trust in the new technology and explaining some areas, such as the impact of the electromagnetic field (EMF) on the environment. So, to promote the dialogue with public and in reaction to a number of questions, CTU explains information about 5G from the viewpoint of the use of frequencies and of the public health protection. Information about 5G testing in the Czech Republic or the summary of user benefits is published on other portals as well, e.g., https://www.mpo.cz/cz/e-komunikace-a-posta/elektronicke-komunikace/koncepce-a-strategie/. Yet, a number of questions, fake news and hoaxes spread across public spaces. CTU created an e-mail address 5ghoax@ctu.cz, on which it collects various inquiries and news regarding also false information about 5G networks, and is ready to explain them on this page.

What is 5G?

5G is a new generation of mobile networks, following the previous generation of 3G (which brought Internet into cell phones and enhanced the boom of smartphones) and 4G (which offered much faster data transmission and allowed e.g., watching streamed videos on the go) networks. 5G reflects new communication needs by end-users as well as the industry and other sectors.

To optimise traffic and decrease interference, the so-called active antennas are used to improve the use of frequencies by directing radiated radio wave beams. Active antennas allow the base station to dynamically direct the transmitted signal (radio beams) especially to places where terminals are located. The technology of beam electrical direction without the need to mechanically set up the antenna is used for decades now by various radio systems, however, only after the further optimization of the use of frequencies was needed (and the related technological development) the dynamic direction of antennas radiation was introduced also into common commercial systems.

What will 5G bring?

The main contribution of 5G networks is expected in further improvement of quality of currently offered Internet access services and in changing the way of using current equipment like smartphones or game consoles. 5G networks have the capacity to connect thousands of such devices at one moment, thus opening a space for development of new and innovative services. Thanks to better connectivity, more people will have access to digital education and digital skills. Faster and more stable connection can connect teams on multiple places at once, which promotes remote working. The factories can be modernised by automated processes and interlinked machines to increase work safety and productivity.

What is the difference between 5G and previous technologies?

5G is an improved development phase from the IMT-2020 technology family (incl. 3G and 4G). 5G is developed for the better use of frequencies and decrease of mutual interference. The benefits also include improved transmission speed for individual users (incl. lower latency), or possible use of 5G for highly reliable connection. When using ultra-wideband radio channels in higher frequency band it is possible to attain transmission speeds up to gigabits.

Which bands are used for 5G?

5G development is a technological development in the field of mobile technologies which reacts to increased demands of users on volume and speed of the transmitted data, including the best possible availability of the wireless networks signal. Since the range of available frequencies for ultra-wideband channels in lower bands is limited, higher bands are sought (these are already being used by other technologies). 5G can or will be able to use a range of frequency bands already designated for mobile communications 2G, 3G and 4G, including the 3.4 - 3.8 GHz band. Information about bands used by mobile networks can be found at spektrum.ctu.cz. New bands designated specifically for 5G include 700 MHz band or 26 GHz band, which will allow use of ultra-wideband channels. Other bands, such as 66 - 71 GHz, will be also used by 5G.

How far is Czechia with preparations?

Frequencies in the bands 700 MHz and 3.4 - 3.8 GHz needed for deployment of 5G networks have already been the subject of frequency auctions. The deployment of wider networks is already underway in both zones.

Are 5G networks a risk for human health?

No, they aren’t. When sticking to hygienic limits, the 5G network transmitters do not negatively affect human health (see more below). The National Institute of Public Health published on its website Information No. 20/2019 of the National Reference Laboratory for Non-Ionizing Electromagnetic Fields and Radiation of the National Institute of Public Health, which reacts on growing fears and inquiries regarding health protection from electromagnetic field (non-ionizing radiation) caused by 5G networks.

How do radio waves affect people and what is the scientific explanation?

After penetrating the biological tissue, the electromagnetic field (EMF) of radio frequencies causes thermal reaction. To briefly explain and clarify extreme cases, it is necessary to explain macroscopic approach to EMF spread as well as microscopical approach from molecular physics.

The macroscopic approach is based on EMF spread principles, which are collectively described by Maxwell equations and can explain the EMF wave behaviour in different environments starting with vacuum and ending, in our case, with the environment with high volume of water and other substances, which collectively change the basic parameters of the examined environment (here especially permittivity and conductivity). Without explaining the derivation, we will present one of formulas to calculate the thermal effect when the wave penetrates the body. The examined quantity is SAR (specific absorption rate, in W/kg):

SAR = σ . Ei2 / ρ, where

Ei means intensity of electric field inside body tissue (V/m),

σ means electrical conductivity of body tissue (S/m), and

ρ means sample density (kg/m3).


To determine Ei, it is necessary to calculate EMF wave penetration to a different environment while using above mentioned parameters. With regard to the purpose of this text, we do not present the method. SAR can be determined by other methods, for example measuring. The resulting SAR in a common environment (incl. e.g., person exposure to a cell phone) must not be higher than it is set by hygienic limits. These limits are in the Czech Republic defined (under the Act on Protection of Public Health) by Government Order No. 291/2015 Coll., on protection of health from non-ionising radiation, which follows the ICNIRP recommendation. In reality, to make assessing exposure simpler, so-called reference values are used, which include a high safety coefficient and take into consideration also the methodology of measuring EMF parameters by a device in the air (i.e., outside body). In case of EMF, it is the density of radiant flux (in W/m2). For higher frequency bands (approx. over 6 GHz) the depth of wave penetration into the body is so small, that only prevailing square exposures (by density of radiant flux) is assessed.

Microscopical (molecular) explanation of EMF impact on biological tissue is rather complicated and uses particle description of EMF - electromagnetic wave is a current of photons (energetic quanta), where the energy of single photon is given by E = h . f, where f is frequency (Hz), h is Planck's constant (4,135667696 × 10−15 eV . s) and resulting energy E is in electronvolt (eV). If the photons of EMF interact with atoms or molecules (i.e., enter into biological tissue constituted by proteins and other substances), they pass their energy to these atoms or molecules and these will increase their internal energy, which is shown as oscillation (kinetic energy of particles). On the outside (macroscopic) this increase of internal energy is shown by increase of temperature. At the same time, due to the mutual movement of atoms and molecules, the energy is further transferred to other particles, meaning the energy is diffused (thermal conduction). This is done by mutual interaction of particles as well as via chemical or physical bonds. (Note: Thermal energy of particle of each substance with temperature above 0 Kelvin is shown by their movement.)

If the photon’s energy is very high (e.g., x-ray ionizing radiation), an electron can be released from an atom (molecule) and free radicals can be ionized and created. This effect, which can cause structural changes of DNA, replication mechanisms of cells or chromosomes, or other changes, can cause some of oncological diseases. However, the energy necessary for ionisation of e.g., biologically important carbon is ca. 11 eV, which corresponds to a frequency of approx. 2.7 x 1015 Hz (wavelength of 110 nm). These are of approx. 5 magnitudes higher frequencies than those used by radio communications. Therefore, EMF wave photon in radio frequencies (i.e. non-ionizing radiation) cannot cause ionization of atoms or molecules.

An interesting question is what will happen if there is a large amount of such non-ionising photons, or – from macroscopic point of view – the power radiated by a transmitter (thus affecting biological tissue) is rather high and body’s thermoregulation processes (especially blood circulation, sweating and energy radiation) would not be able to deal with such amount of energy. In such case, each photon causes the above described gradually increase of internal energy of atoms and molecules (oscillation) and thus increase of temperature. In case of biological tissue (consisted of proteins and other substances with high volume of water), further heating causes irreversible damage of protein chains (coagulation) due to disruption of molecular bonds. However, this can occur only during multiple exceeding of allowed exposure and would be accompanied by e.g., burns.

Hygienic limits for protection of public health from EMF effects (and used safety coefficients) are defined so such injuries could not possibly happen.

Does EMF affect health in long run?

The effects of EMF on health, incl. long term effects, has been studied for decades across states, expert teams and institutions. Several methodologies of epidemiological research were applied. More precisely, the connection between use of mobile phone and head carcinoma incidence was researched. No significant connection of mobile networks affecting human health was proven.

What about exposure with increasing number of transmitters (5G)?

The power radiated by mobile networks base stations transmitters in bands, which are (or will be) used for 5G technologies, is rather low (power delivered to 2G–4G base stations regular antennas is usually of a maximum 20 W, and in bands over 26 GHz will be lower than 1 W). Since the antenna spreads the radiated power into the area (around it), the signal intensity in the covered areas is usually low. The density of radiant flux decreases with square distance, which also helps to reach lower levels. From a physical point of view, the effects of transmitters are added; however, since the exposure of a person to base station transmitter is usually rather low, under normal circumstances, it concerns only sums of very small numbers. Given the fact, that other than thermal effect is not known for EMF, the value of total exposure is not substantial for health. In reality, the exposure is so low, that with regard to thermoregulation mechanisms in a body, no measurable or provable increase of temperature in human body happens.

(Note: Specific exposure varies according to specific place and cannot be generalised. However, the exposure median for 2G/3G/4G base stations is usually lower, one thousandth of reference value of density of radiant flux.)

Who defines hygienical standards for EMF exposure in the Czech Republic and how?

The area of protection of public health from effects of non-ionising radiation is regulated by Government Order No. 291/2015 Coll., which is an implementing act to Act on Protection of Public Health. The National Institute of Public Health prepares proposals of this act or amending acts for the Ministry of Health. The Institute is also authorised with methodology governance for non-ionising radiation sector. Since 2000, exposure limits and methodology procedures for evaluation of exposure are set in the Czech Republic according to ICNIRP Commission recommendations.

Which measures are taken to ensure compliance with hygienical standards?

Government Order No. 291/2015 Coll., on protection of health from non-ionising radiation defines not only permitted exposure values, but also the methodology for evaluation of exposure. The operator of installed devices (e.g., transmitters) is responsible for compliance with exposure; the evaluation is done by hygienical station or special units. As for commonly sold products (smartphones, routers, etc.), the evaluation is done by the manufacturer in compliance with rules and procedures, which also follow recommendations of ICNIRP and other institutions, which publish relevant recommendations or standards (e.g., IEEE, CENELEC). If the values applicable for given exposure situation is complied, it is assured that the exposed person will not be injured.

What is ICNIRP?

The International Commission on Non-Ionizing Radiation Protection (ICNIRP, https://www.icnirp.org/) is an organisation under WHO, which unites experts from around the world on associated fields of biology, epidemiology, medicine, physics and chemistry, who engage in evaluation of biological effects and mechanisms of non-ionising radiation. The Commission publishes recommendations on protection of health from non-ionising radiation, including recommended evaluation methodologies. ICNIRP expert conclusions are always subject to a thorough review proceeding and then published. ICNIRP Recommendations are elaborated on scientific basis (so-called evidence-based) and are, for example, comparable to conclusions from other expert teams (e.g., in IEEE organisation). ICNIRP Recommendations were considered in EU rules and they are transposed in the Czech Republic to Government Order No. 291/2015 Coll., on protection of health from non-ionising radiation.

In 2011, IARC agency placed EMF into category 2B. Why?

International Agency for Research on Cancer (IARC, https://iarc.fr/) is an organisation under WHO. Its activities include mainly international cooperation in cancer research. In 2011, the IARC working group on EMF assessed number of studies on biological effects of EMF. A part of the assessment were also results of an extensive epidemiological study done in Sweden and also under an international study conducted by Interphone between 2000–2004. By questionnaire survey, these studies focused on searching possible correlations between incidence of oncological diseases and mobile phone usage. Some results showed little connection (i.e., insignificant) between using a phone near one’s head and incidence of some cancer diseases. The IARC working group pointed out a number of methodology deficiencies of the studies, starting from absence of control groups to application of other influence (e.g., prejudice). A part of the working group also stated, that the findings are insufficient for making a conclusion on causality. However, with regard to the necessity of common opinion, the conclusion, that the connection between mobile phone usage and certain type of tumour occurrence can be possible, was adopted. With regard to the IARC classification rules, this conclusion corresponds to group 2B – possibly carcinogenic to humans. This category means, that there is a limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.

IARC monography (Vol. 102) does not state quantitative assessment of EMF exposure risk on human health nor does it state the mechanism of EMF influence, which could potentially explain the cause of oncological diseases. IARC did not find connection between common exposure (i.e., a stay in a common space without using a mobile phone).

In 2019, IARC Advisory Group recommended priority re-evaluation of current EMF classification by 2024.

What is CTU’s role?

CTU’s role is regulated by the Electronic Communications Act. In relation to mobile networks and radio frequencies, CTU mainly sets suitable technical conditions for the use of frequencies by transmitters (and receivers), grants individual rights to operate transmitters, and generally supports conditions for connection of end-users to mobile (and other) networks. Conditions and rules set by CTU follow also the European regulatory framework, including relevant technical standards.