Bengaluru: 5G wireless technology continues to court the news for controversial reasons, this time with actress Juhi Chawla filing a plea in the Delhi High Court against the technology, citing risks from radiation.
The technology is expected to be incredibly fast with high capacities, and many carriers worldwide have already rolled it out in select locations across the world. The network achieves speeds measuring in gigabits per second thanks to its additional use of a higher band of radio frequencies for communication, called millimetre waves.
While there have been a lack of rigorous studies in the newer part of the spectrum that 5G technology uses, scientists and radiation watchdogs have cleared the spectrum for cell phone technology use, citing existing health safety data.
Millimetre wave communication comes with a tremendous attenuation problem, posing challenges to the implementation of the technology. High band 5G has extremely short range, going in mere feet or meters, and signals are impeded very easily by minor obstacles like trees, buildings, or even rain.
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How 5G works
5G is the fifth generation of wireless networks, offering high speeds and capacity.
Work into developing a fifth generation wireless technology first began in 2008 at NASA, but also simultaneously and independently in multiple places around the world. Tech companies like Samsung, Nippon, Huawei and LG have all done work on the technology and are developing it.
South Korea and the United States rolled out the technology on the same day to the public in select locations in April 2019.
The band that 5G uses is divided into three sections: Low band, mid band and high band microwaves. At 600 to 850 megahertz, low band 5G uses similar frequencies as 4G and our regular cell phones. Mid band 5G uses microwaves of 2.5 to 3.7 gigahertz, and can give speeds of almost 9,000 megabits per second. The newer part of the spectrum that is being used, called the high band microwave, uses frequencies of 25 to 39 gigahertz, which is in the millimetre wave band. This can provide normal speeds in gigabits per second range.
Because of the frequencies at which they operate, high speed 5G devices and nodes will indeed emit radio frequencies that are 10 to 100 times higher than what we operate cell phones on, but, unlike Chawla’s claim, such radiation is already present all around us from other natural and artificial sources, and scatter quickly.
5G network setup
5G networks are compatible with 5G devices only, which are equipped with compatible radio transceivers. The network consists of different types of hubs or nodes called cells.
5G nodes have a very limited coverage area, and thus require “small cells” every 10 to 100 metres. These small cells will make up the high speed, short range network. They can be femtocells, picocells or microcells with ranges of 10m, 200m and 2km, respectively, when in direct line of sight in clear weather.
These small cells then connect to or communicate with macro cells, which use mid and low bands of microwaves and carry out long range transmission.
5G antennae are also equipped with the ability to directly transmit towards a desired direction. Such antennae are called directional phase-array antennae.
The need to install large number of cells all around to enable the network has raised the question of both privacy and health risks from close exposure to directional waves, both from small cells as well as from 5G cell phones into human ears.
What are the health concerns
The electromagnetic spectrum represents all energy around us. Radiation that is of a higher frequency than visible light — such as ultraviolet, X-rays and gamma rays — have enough energy to dislodge electrons from atoms they hit. Thus, they are called ionising radiation.
This kind of radiation has the potential to cause cellular and DNA damage to our bodies upon exposure, increasing the risks of cancer.
However, frequencies below visible light — going from infrared to microwaves to long range radio waves — are non ionising. Radio and microwaves have been used for communication for decades. While higher frequency millimetre waves tend to lose energy faster, they are already used for point-to-point communications and in television broadcasting, radars, astronomy, cell phones, and so on.
Millimetre waves, used in 5G, are smaller than 1mm in wavelength, and have not been used for mobile communication before. They are incapable of causing molecular or cellular level damage to our bodies.
There are still concerns of tissue damage from heat, as higher energy waves move closer to infrared on the electromagnetic spectrum. Infrared radiation carries heat, and half the sun’s energy also reaches Earth in this form. But experts have pointed out that the millimetre wave band that 5G uses, from 25 to 39 GHz, is actually closer to radio frequencies and farther away from infrared, which begins at frequencies of 5-20 terahertz and have wavelengths in micrometers.
Additionally, communications technology utilises a much lower power output, both at nodes and in personal devices, to cause any serious damage to the body as far as we understand today.
Radiation experts say 5G is safe
Given how new the technology is, there have not been many rigorous studies of long-term use of millimetre waves for cell phone communication. The WHO says, “Health-related conclusions are drawn from studies performed across the entire radio spectrum but, so far, only a few studies have been carried out at the frequencies to be used by 5G. Tissue heating is the main mechanism of interaction between radio frequency fields and the human body.”
However, 5G has been declared safe and the newer frequencies cleared for use, health-wise, by radiation watchdogs and international bodies.
The two international bodies that produce exposure guidelines on electromagnetic fields — the International Commission on Non-Ionizing Radiation Protection and the International Committee on Electromagnetic Safety — cover radio frequencies up to 300 GHz in their studies on health impact, including the frequencies to be used for 5G.
The WHO is currently conducting a health risk assessment from exposure to all radio frequencies, including the ones that will be used for 5G and the ones that are already in use. The report is expected to be published in 2022.
(Edited by Manasa Mohan)