These strange "pretenders" around us are actually very useful

The weather is getting cooler, and it is a good time to go for a walk. If you pay close attention while walking on the road, you may find that some trees look strange:

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

Although they "grow" together with other trees, they are much taller, and between their "leaves" there are square-shaped things that look like speakers.

What exactly are these strange trees?

Before the answer is revealed, you can guess first~

3.2.1……

They are actually base stations .

In addition to disguising themselves as big trees, base stations can also appear in more unexpected forms.

For example, the "solar water heater" on the roof of the building below does not provide hot water, but provides mobile signals for people in the building.

A base station disguised as a solar water heater. Image from the Internet

Some "air conditioner outdoor units" on the roof or wall never rotate their fan blades because they are also base stations.

A base station disguised as an air conditioner. Image from the Internet

"Street Light Base Station"

The picture comes from the Internet

"Manhole Cover Base Station"

The picture comes from the Internet

Why have good base stations become "pretenders" one after another?

Let’s start with the surge in the number of base stations.

Why do we need so many base stations?

With the advent of the 5G era, the speed of mobile Internet access is getting faster and faster, and the credit behind this super-fast Internet speed goes to the base stations that are silently working in every corner of the city.

Of course, base stations are not a product unique to the 5G era. However , the demand for base stations in 5G networks is much greater than in the 3G and 4G eras.

Compared with 3G and 4G signals, 5G signals use higher frequency electromagnetic wave bands , which can achieve faster data transmission speeds.

However, electromagnetic waves are affected by many factors during their propagation.

For example, the atmosphere and rain will attenuate the strength of electromagnetic wave signals, and the higher the frequency of the electromagnetic wave, the more severe the attenuation. In addition, under the same power, the ability of high-frequency electromagnetic wave signals to penetrate reinforced concrete buildings is also weaker than that of low-frequency electromagnetic waves.

Millimeter wave atmospheric absorption rate, image source: Reference 2

Therefore, the coverage range of mobile base stations used to transmit and receive 5G signals is smaller than that of 3G and 4G base stations.

For example, under normal circumstances, the coverage range of 3G signal base stations in cities can reach about 2 to 5 kilometers, the coverage range of 4G signal base stations is 1 to 3 kilometers, and the coverage range of 5G base stations is only 100 to 300 meters.

In order for mobile devices throughout the city to receive 5G signals, more mobile base stations are needed.

In 2017, my country opened its first 5G base station. According to data from the Ministry of Industry and Information Technology, by the end of July 2024, my country has built a total of 3.996 million 5G base stations, which is about to exceed 4 million. The number of 5G base stations accounts for more than 30% of the total number of base stations.

And with the further popularization and application of 5G networks, the number of 5G base stations will further increase. It can be said that 5G base stations will be "ubiquitous" in the future.

Why are these base stations?

A weird disguise?

1

Avoid the psychological concerns of being afraid of talking about "gay"

Signal base stations provide signals to mobile devices through electromagnetic fields, which inevitably generate electromagnetic radiation. When some people hear the word "radiation", they get scared and worry that it will harm their health. But in fact, the radiation generated by base stations that we usually come into contact with does not affect our health.

Ionizing and non-ionizing radiation

Common radiation can be divided into two types: ionizing radiation and non-ionizing radiation.

Among them, the energy of ionizing radiation is relatively high and may damage the DNA structure in cells. X-rays, gamma rays, and nuclear radiation all belong to this type of radiation. Exposure to high doses of ionizing radiation does have an impact on health, but the radiation dose received during daily physical examinations, security scanners, etc. is very low, so there is no need to worry too much.

The radiation generated by base stations is not ionizing radiation, but relatively low-energy non-ionizing radiation, which is not energetic enough to damage the DNA structure inside cells.

Ionizing radiation and non-ionizing radiation, Image source: Reference 4

As early as 1996, when mobile signals began to become popular, the World Health Organization had already established the "International Electromagnetic Field Project" to assess the possible health risks of electromagnetic fields from mobile phones and base stations. However, until now, there is still no evidence that the radiation generated by mobile phones and mobile base stations will have teratogenic and carcinogenic effects.

The impact of non-ionizing radiation generated by mobile phones and base stations on the human body mainly comes from the thermal effect. To put it bluntly, long-term exposure to high-power non-ionizing radiation may cause burns.

Moreover, the power of mobile base stations is strictly limited . Our country's "Electromagnetic Environment Control Limits" (GB8702-2014) has set limits on the power density of electromagnetic fields generated by communication equipment. The limit standards are more than 10 times stricter than those of the European Union, the United States, and Japan.

In addition, as the number of base stations increases, the coverage area of ​​each base station becomes smaller, and the required transmission power becomes lower. The transmission power of micro-base stations and pico-micro-base stations installed in residential areas and on the roofs of residential buildings is even lower than that of household lighting.

Therefore, there is no need to worry that base station radiation will affect human health.

2

Practical and beautiful

In addition to avoiding the psychological concerns of a small number of people, the shape of the base station also takes into account the aesthetics of the environment. After all, a base station "disguised" as a tree looks much more beautiful than a lonely "base station tower".

Some base stations even have additional prompt functions:

A "disguised base station" that also provides a reminder function. Image from the Internet

In addition, in some scenic spots, in order to ensure that people can use the 5G network normally without destroying the scenery, such "wooden base stations" and "stone base stations" have also appeared:

Wooden base station. Image from the Internet

A base station disguised as stone on Mount Tai. Image from the Internet

So, if you find these "fake base stations" on the roadside, don't be surprised. Take a photo quickly, and then use the signal they provide for you to send a circle of friends!

References

[1]https://support.huawei.com/enterprise/zh/doc/EDOC1000113314/b4231b86

[2] TS Rappaport et al., "Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!" in IEEE Access, vol. 1, pp. 335-349, 2013, doi: 10.1109/ACCESS.2013.2260813.

[3] https://www.cac.gov.cn/2024-03/26/c_1713127245927656.htm

[4] https://www.iaea.org/zh/newscenter/news/shi-yao-shi-fu-she

[5] https://www.who.int/news-room/fact-sheets/detail/electromagnetic-fields-and-public-health-mobile-phones

[6] https://www2.deloitte.com/content/dam/Deloitte/cn/Documents/technology-media-telecommunications/deloitte-cn-tmt-predictions-2021-chapter-3-zh-201214.pdf

Planning and production

Author: Science Scraps Popular Science Creator

Review | Cui Yuanhao Associate Researcher, School of System Design and Intelligent Manufacturing, Southern University of Science and Technology

Planning丨Yang Yaping

Editor: Yang Yaping

Proofread by Xu Lai and Lin Lin