that helps you think like an engineer.

Okay, I didn't think I would need to make this video, but people are burning valuable

infrastructure down out of fear for their health. I'm sure you have heard all the

insane theories. 5G towers are weakening the immune system and causing the global pandemic.

5G is causing cancer. 5G is mind control by the lizard people.

I don't think I will succeed in convincing many of the lunatics that believe these things,

so I'm not going to try, but let's explore what 5G actually is, how it works, and some

of it's real problems. Today we are going to learn some interesting things about data

transmission science and how our ability to transfer data through the air has evolved

over the past 4 decades. Hopefully we can pull a few of the people on the fence over

to the side where the rational people live in the process.

We have been using different wavelengths of electromagnetic radiation to transmit information

for hundreds of years. In ancient Greece they used signal fires to convey messages with

visible light. Today we send messages with light through fibre optic cables. These cables

are capable of carrying insane quantities of information and are the bedrock of the

internet, but we can't connect all devices to it, because many devices need to be wireless.

To make wireless data transmission possible, cellular networks needed to be developed and

it all started here in Japan in 1979, with the first generation cellular network, which

we now call 1G.

It began in Tokyo where high power radio towers would communicate directly with phones installed

in cars. These towers used radio waves with frequencies sitting around here on the electromagnetic

spectrum, and simply transferred the data in analog.

Let's see how analog data can be transmitted using a carrier frequency. Say we want to

send this sound wave, a simple sine wave of 100 Hertz. We want to apply it to a 850 MHz

wave, a wave with significantly higher frequency.

We can do this with amplitude modulation, or frequency modulation. AM and FM. You have

definitely heard of these terms before with radio stations.

AM applies the data to the amplitude of the carried frequency, so it will vary the amplitude

of the carrier frequency, like so, basically tracing the original wave with its peaks and

troughs. [Reference Image 1]

FM applies the data to the frequency of the carrier wave, like so. Varying the distance

between peaks to trace the original wave.

To transfer a call using this method, you need a dedicated frequency band ,defined by

the lowest and highest frequencies used.

If another user is using that frequency band on the same tower, then you need to use a

different frequency band. The more frequencies you have, the more calls the tower can handle.

This is bandwidth.

As the number of users grew, the system's capabilities were continually stretched. Adding

more frequencies to grow bandwidth is an option, but adding frequencies comes with it's difficulties.

Frequencies need to be licensed and there is a lot of competition. Weather radar, military

communication and security systems, GPS, television broadcasts, radio stations, radio astronomy,

aviation systems and air traffic control. They all need their own frequency bands. In

order to gain new frequency bands companies often had to go to auction and purchase the

license with huge capital investment.

This was done with every new generation of cell network. But a lot was done to cram more

data onto a single frequency band through the years.

Increasing the number of users that can use the same frequency band can be as simple as

increasing the number of towers. Instead of using a single high power tower to cover an

entire city, multiple lower power towers could be used. Frequency bands could then be assigned

to individual customers within each tower's range without interfering with the same band

in neighbouring cells.

This increased the number of users networks could support, but it did not increase data

transfer rates. At it's best 1G was capable of about 2.4kilobits per second, but describing

it in bits per second is a bit counter intuitive, because as we said, it worked in analog. Bits

were the units of digital data.

2G ushered in a new era of mobile phones with the introduction of a fully digital system.

Instead of encoding an analog signal into a frequency band, we encoded binary data.

If you are like me, this was your first experience with cellular networks. My first phone was

this beast. The legendary Nokia 3310. Sure it could make calls, but digital data allowed

for a new form of communication.

This was the era a new language was born. Text speak. a language of gibberish invented

to keep within the 160 character limit and prevent your mobile network provider from

charging you for two texts.

In english, each character in that 160 character text was encoded with 7 bits. [4] Therefore

a 160 character text contained 1120 bits.

When 2G was first introduced it could achieve about 9.6 kbit/second. It could handle that

1120 bit text message with ease. But the 2G era lasted right up to the launch of the first

Iphone, and speeds had increased to 200 kilobits/second thanks to improved internet protocols like

General Packet Radio Switching or GPRS, sometimes referred to as 2.5G.

By the time the iPhone 2 launched, 3G was the new hot topic.

3G introduced additional frequency bands, it's estimated that in Europe alone companies

paid over 100 billion dollars in auctions to gain new frequencies.

But 3G also made the change to a system that fully utilized the method of data packet switching,

which GPRS utilized. Packet switching allowed thousands of customers to share many different

frequency bands far more efficiently.

Here data was split into small data packets. Each data packet contains a header, which

contains the address of the destination and information on how to reassemble the data

packets.Splitting the data up into smaller bite sized chunks allowed us to make better

use of the frequency bands available. Instead of trying to find a large gap of availability

on a single frequency band, we could split the data into small chunks and send it across

many different frequency bands the moment a small availability appeared.

Like changing from sending a huge truck of data on a single road, to sending thousands

of motorcycle messengers over the roads with the least traffic.

This made our use of the frequency bands capacity more efficient and allowed us to carry more

data. As time went on these protocols improved allowing even more efficient use of the bandwidth.

In 2005 High Speed Packet Access of HSPA, which you have likely seen represented on

your phone as a H+, was introduced which increased speeds up to 42 MBPS. This was labelled 3.5G.

4G introduced a new technology called Long Term Evolution or LTE, it introduced even

more frequency bands like the 700 MHz band that was previously used for analog TV broadcasts.

It also introduced a new way squeezing more data through the existing frequency bands

with Orthogonal Frequency Division Multiplexing or OFDM. [6]

OFDM allowed us to send far more data. You are probably familiar with the idea of constructive

and destructive interference. Where two waves meeting can combine and either enhance or

cancel out the amplitude of each other.

To prevent this signals traditionally had to be separated out over time to prevent interference,

but OFDM allowed the signals to be squeezed together and overlapped, allowing the same

amount of data to be sent over a shorter period of time. When the signals arrived they were

separated out and converted to binary data once again.

How? I don't know. Magic or math or something.

Honestly, the fact we can stream HD movies on our phone without a wired connection should

seem like magic to the average person.

It has gotten so advanced that we are now struggling to increase speeds without adding

new frequency bands, but there aren't a whole lot available, so network providers

are now reaching into the bargain bin and taking out frequencies no-body wants to use.

Higher frequency millimetre waves.

Higher frequency waves have normally been shunned for these types of applications. High

frequency waves just aren't as good at travelling. They get blocked by practically everything

including rain, think of them like visible light. Unless you have a direct line of sight

with a torch, you can't see it.

To deal with this network providers need to install huge numbers of transmitters. Studies

have estimated that to bring 100 Mbps download speeds to 72% population coverage and 1 Gbps

speeds to 55% of the US population, about 13 million utility pole mounted 28 GHz base

stations would be needed at a cost of 400 billion dollars. [6]

Having this many base stations will help relieve congestion over a single frequency band, but

5G will also be using something called massive mimo. Or massive multiple input multiple output.

These are basically just groups of antennas that are listening and broadcasting the same

frequency bands. This would cause interference, but 5G is also looking to use beamforming

which will allow the antenna to aim at your phone instead of broadcasting the signal in

all directions.

This coupled with the fact that higher frequency waves can carry more data means 5G is reaching

speeds of up 1800 Mbps in the US.

Higher frequencies can carry more information because we are encoding our information into

the wave cycles. Our measure of frequency is hertz, but all 1 hz really means is that

1 wave cycle is reaching us per second, 10 hertz means 10 wave cycles are reaching us

per second. 190 Megahertz means 190 million wave cycles are arriving per second. Because

we are encoding our information into the wave cycles, that means we can encode more information

into higher frequency waves.

Up until now we have been using frequencies between 700 MHz and about 2500 MHz. So 700

million wave cycles per second to 2500 million wave cycles per second.

5G however is looking to use frequencies as high as 90 GIGAhertz. That's 90 billion

wave cycles per second. A major step up.

5G will allow higher download speeds and lower latency. This will be huge for time critical

technologies like self driving cars that require rapid communication between vehicles in the

network and allow even more devices to join the network. To create the internet of things.

5G has a lot of potential, and no it's not dangerous.

The electromagnetic spectrum starts on the far left with gamma radiation, which has very

high frequency and short wavelengths. Higher frequencies and shorter wavelengths equates

to higher energy, and indeed gamma radiation does cause cancer. Anything over here you

need to be worried about, that's ionising radiation. Meaning it removes electrons and

damages things like your DNA, but 5G is operating all the way over here towards the lower energy

frequencies. Yes, past visible light, which last time I checked no-one is afraid of.

Yes, like visible light and microwaves it's possible to cause heating with high enough

powered beams of these wavelengths. This is the only non crackpot theory I can find on

5G that actually sits in the realm of plausibility. The military even used high powered 95 GHz

beams in their active denial system, which just made the people on the receiving end

feel like someone just opened an oven door in front of their face and it could burn people

if exposed for long enough. It's uncomfortable and was intended to disperse crowds.

This was essentially a focused beam of 95 GHz light, akin to a massive magnifying glass

to focusing light to burn a piece of paper. Because yes, just as visible light can be

used to cause heating, so can these wavelengths when used in high enough power and intensity.

As we said earlier these frequencies are blocked by rain and so they certainly can't penetrate

your skin and these transmitters simply don't have the power to cause heating that would

be damaging. They are just simply too low power and there are plenty of studies that

show that they are not harmful. If you are afraid of 5G in this way, you might as well

be afraid of the streetlights because they emit higher energy frequencies.

Every day technologies like this can seem like magic until you peel back the layers

to their earliest iteration and see that they are just the product of many years of problem

solving with each successive generation adding more complexity. If you would like to learn

more about the whole electromagnetic spectrum, including which parts are dangerous and which

aren't, you should check out Brilliant's course that unravels the physics of Waves and Light.

Inside you'll learn things like how light can exhibit particle-like and wave-like behaviours,

how much energy electromagnetic radiation can carry, and even how to measure the speed

of light.

You can set a goal to improve yourself, and then work at that goal a little bit every

day. Brilliant makes that easy with interactive explorations and a mobile app that you can

take with you wherever you are.

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