stein@opensky
After a busy December and a Christmas break in lockdown times, here is finally another commentary from me. I have with interest seen this topic developing over the last year or two. As a radio engineer by education – and having been involved in every G since 2G was under development, I am not surprised to see the hysteria in the media around 5G and EMF. I am more surprised by the vandalism and physical attacks on network infrastructure, however. I will not comment on the even crazier hysteria around 5G and COVID 19, however, please find below some comments from my side around 5G and health.
Concerns around mobile networks and EMF are not new. I have seen them for every G ever since 2G (refer various previous articles about 5G and previous generations, e.g. here, here and several others). Concerns might have been present in analog 1G networks as well. However, at that time, cellular mobile communication was not very widespread – and in my country Norway, you even needed a license to buy a mobile phone in the early 80s – and it cost around 3.000 GBP to buy – so any EMF concerns would not have been very visible. At the time, that phone was also mostly a (hardly transportable) car phone.
The mobile industry has always tried to counter the concerns and allegations around mobile communications and EMF in a professional way – being consciously aware of the risk that they might be perceived protecting their own business. Therefore, they have often used a rather reactive approach to the topic – rather than any proactive messaging. Operators I have known have 1) consistently referred to facts and scientific research studies and 2) tried to educate customers around facts and research. Audiences have been individuals, interest groups, municipalities, housing cooperatives and many more.
The global industry association for mobile operators, GSMA, has released various documents on the matter over the years, which have been referenced by operators, the latest of which can be found here. This GSMA document refers to recognized international sources like the International Commission for Non-Ionizing Radiation Protection (ICNIRP) which provides scientific advice and guidance on the health and environmental effects of non-ionizing radiation, working in close collaboration with the World Health Organization (WHO) and other government agencies. The main conclusion has always been that (“for mobile devices or base stations that comply with the limits in the ICNIRP guidelines”) “EMF exposures below the limits recommended in the ICNIRP international guidelines do not appear to have any known consequence on health”.
It should be noted that the ICNIRP guidelines are quite technical and deal with potential health hazards when exposed to radio frequency (RF) electromagnetic fields (EMF). Radio frequencies are frequencies used for radio communication, i.e. extremely different from the frequencies of visible light or even higher frequencies (see below) – and EMF in this context is assessed as power density in watts per square meter (W/m2). This power density relates to the impact it could have on a certain human body surface and the heating effect the non-ionizing radiation might potentially have on the body. I would like to stress the term non-ionizing in contrast to ionizing – which is what could occur from radioactive radiation. This may be an unfortunate and common confusion.
Radiation ≠ Radioactivity. Ionizing radiation (e.g. X-rays, gamma rays etc with extremely high energy – enough to damage DNA by removing electrons from atoms) are a totally different matter (refer also these basics from the United States Nuclear Regulatory Commission). In comparison, ionizing radiation can only occur at extremely different frequencies. As an example, gamma rays occur in the 300 EHz band – which is 300 billion times the frequency of 1 GHz, i.e. very far from any relevant spectrum for mobile services (see also these spectrum basics from the CTIA) – and in between there is also visible light (having a 1000x lower frequency). While ultraviolet light (with frequencies 10-100x of visible light) can give you a sunburn if exposed to strong radiation for a long time, visible light is what you are exposed to every day from everywhere. As a curiosity, referring to the picture in the article, visible light from light bulbs also caused some concerns in the days they were introduced. By the way, traditional light bulbs typically use 15 -100 watts of power – and a person sitting close to a light bulb might be exposed to thousands of more radiation than a person 10 m away from a base station.
Statements from the ICNIRP and the WHO will probably reassure most consumers; however, they don’t seem to work on social media and activists. In addition to the GSMA, many other sources have tried to explain facts and basics around mobile services and EMF – one of which is this one on “5G is not hazardous to your health: Busting the radiation risk myth” from Deloitte Insights. I don’t expect that any statements from me will have any effect on activists and sceptics who believe in fake news and whatever they may see in social media. However, I will add some comments (non-exhaustive) in any case – basically with some explanations I have used in the past:
Radiation ≠ Radioactivity: This one is commented above and needs no repetition, however, the confusion may explain some of the hysteria.
Mobile transmits with extremely low power: In the early days of 2G, mobile phones mostly transmitted with a maximum peak power of up to 2 watts, however, this was not on a continuous basis. It transmitted only one eighth of the time. On average, the transmit power was therefore correspondingly lower. On top of this, 2G phones have adaptive power control – such that they only transmit the power needed to reach the base station – which depends on the distance from the base station. The closer to the base station, the lower the transmitted power. Therefore, with the increasing density of cells in mobile networks needed when the customer base grows (and the increased implementation of small cells), mobile phones on average transmit with very low power. Base stations, on the other hand, transmit with higher power, e.g. up to a few hundred watts for a rural base station. However, a person with a receiver would normally be quite distant from the base station in such a case. Indoor small cells would be much closer but with a correspondingly lower output power, not too different from that of a mobile phone (e.g. 10 - 100 milliwatts).
The further away, the lower exposure: While a mobile phone may radiate directly into your head (when speaking though – less when surfing), a base station is located far away (down to around 1 meter for small cells and maybe up to 30 km for rural cells) – and the mobile signal attenuates significantly with distance. A person around one meter away from a small cell will on average experience of the order of 1000x lower power than actually transmitted – and the received power will decrease with the square of the distance. When the base station is far away, the received power is many orders of magnitude lower. As an example, a 2G mobile phone is designed to work with a received signal strength of down to -104 dBm (which means a power level of 60 trillion times lower than 1 mW) – and as the base stations utilize adaptive control to minimize the transmitted power, the received power will mostly be as close to this power level as possible. In fact, I am not aware of any measurements or practical trials that have seen radiation exposure reaching even 1% of the international ICNIRP guidelines (i.e. a factor of 100x).
Mobile phones give higher exposure than base stations: Having built a few mobile networks, I have from time-to-time experienced people who don’t want to have base stations on their property, not only due to aesthetics but also due to fear of radiation. They want coverage, but not base stations close to their houses. The fact is, however, that base stations with antennas e.g. 30 m above ground will generate a received power of much less than mobile phones at your ear – and, in addition, they normally point away from the house – so the received power is even lower directly at the site.
Recognized safe levels: In simplified terms, according to the ICNIRP, recommended safe levels of radiation exposure from frequencies relevant for mobile services are of the order of 10 W/m2 for whole-body exposure - or 20-40 W/m2 (2-4 mW/cm2) for local exposure. The whole-body exposure will relate to exposure from a base station due to the distance – while local exposure will relate to exposure from a mobile phone at the ear.
Low power compared to regular household equipment: Many mobile services use the frequencies in the range not too far from 2 GHz. This is similar to the frequency range used by microwave ovens which emit a power of 1-2 kilowatts (kW). In comparison, mobile phones transmit often down to around 1-2 milliwatts (mW) – which is one million times lower power.
Every G is safer than the previous G: Various examples are provided above based on 2G, which was designed already in the mid-80s with adaptive power control to minimize the transmitted power. The reasons for this were not only to save power (and money), but also to save interference – which increases the capacity of the system and makes the whole system work better. Since then, every new G has been designed with the same objectives.
5G is not very different from earlier Gs: Although 5G is very different from 4G and other Gs in terms of the core network architecture (and with a clearly improved radio technology), in terms of basics relevant to health 5G is not very different from 4G, 3G or 2G. The actual radio signals are very similar to 4G, both in terms of frequency, modulation and intensity. Therefore, EMF research on 3G and 4G systems is in general equally valid for 5G. 5G frequency bands will also be the same or similar to those used for 4G (except for mmWave spectrum).
Saving energy is improving climate impact: Minimizing output power and the use of energy is not only a commercially good idea, it also makes the networks work better and minimizes the climate impact (see also this previous article on digitalization for climate). In many emerging markets, the power grid is quite poor and limited – and using diesel generators is often necessary. With an efficient use of energy, it may be possible to increase the use of renewable energy like e.g. solar. With 5G, the economic costs around building out the needed infrastructure will in many cases also make it necessary for operators to use infrastructure sharing (see also this previous article) – thus saving the total energy use in the market over time.
5G is designed to use less energy: As previous Gs, 5G has been designed to use less energy than previous Gs to emit less power. There are various features for this, one is the ability for base stations to be put into sleep mode when there are no active users, e.g. at night. Another one is a step-up in the use of beamforming, which concentrates the signal towards the mobile station it communicates with – thus limiting exposure for others.
The more sites, the less they emit: One of the stated concerns around 5G is that, with a hugely increased number of base stations, there will be more radiation around. The fact is, however, that with more base stations each site will transmit with lower power – so in total it will be more or less the same. It also eliminates the exceptional scenario in a which a person happens to be very close to a high-power base station. In addition, with 5G replacing earlier Gs over time, the lower the emissions from each site will be due to the higher energy efficiency.
Researchers don’t care about the G: The WHO, ICNIRP and public radiation authorities are not so interested in 4G or 5G as such. It is the radiated signal level and frequency that matters when they consider health risks.
As I stated initially, this is not an exhaustive commentary, but it shows that the current hysteria around 5G is not well-founded. The EMF emissions from mobile networks and devices are not known to have any adverse effects on the health of people (for any type of G) – and mobile networks and technologies get better at every G in terms of energy efficiency. Therefore, migrating to 5G might even have an overall improvement impact on the total energy usage and climate impact.
One item to study more around 5G relating to health, however, is the use of mmWave spectrum (± 30 GHz) for short range small cells or Fixed Wireless Access (FWA). This band is, however, not yet in use in most countries. The ICNIRP will study this more going forward, however, at this stage the valid exposure guidelines are of the same order as mobile spectrum in current use.
It is true that people continue to surround themselves with more and more devices able to communicate, most of which are not connected via any type of G. WiFi is a widespread technology (which by the way is also getting better with time) – but the number of electric devices in an average household is growing every day. I have referred to light bulbs and microwave ovens above, but there is also a range of other household equipment to consider, e.g. TV sets, radios, electric heaters, refrigerators, smart readers, wearables and much, much more. In addition, high-power electricity lines from the grid, terrestrial TV towers etc are also around. So the “natural” radiation around could have even more impact than mobile.
At the end, it is tempting to speculate in why the hysteria around 5G and EMF exists. There could be various reasons. A fundamental challenge is that most people don’t know too much yet about 5G and how it works – which opens up for speculation. One reason for the hysteria could be that bad news sell better than good news – providing media with incentives. Another could be that social media has little editorial censorship – which opens up for activists to spread conspiration theories and fake news.
Having been in the mobile industry all my life, I may be somewhat biased – so I might make my reservations in this context. However, I am also a radio engineer by education. In any case, there is to date no evidence of any harm from mobile or wireless networks. What the future might bring is anyone’s guess – but I suspect it will be no different. Mobile and wireless communication is everywhere and something we cannot live without - and the Internet of Things is happening. Welcome to the future !
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