We all know Wi-Fi. But do you know Wi-Gig? Can you imagine what it is? Invented by Elon Musk, where everything is
called “Giga”? No, not really. Still, we will talk about Gigahertz and Gigabit
per second. After the video, you will know the next frontier
of Wi-Fi. As a bonus, I will tell you the story about
why we do not need a license to use Wi-Fi. Spoiler: It is because of microwave ovens. Grüezi YouTubers. Here is the guy with the Swiss accent. With a new episode and fresh ideas around
sensors and microcontrollers. Remember: If you subscribe, you will always
sit in the first row. We all know 2.4 and 5.8GHz Wi-Fi. 5.8GHz is faster and, in many areas, less
crowded than 2.4GHz. What would you say if I were to test 60GHz
devices with a promised data rate of 1 Gigabit per second? And see how far it goes. Spoiler: Its range is longer than you think. All wireless systems need bandwidth to transport
data. As a rule of thumb, the higher the data rate,
the wider the signal. However, a higher bandwidth needs a higher
power to bridge a particular distance. Let’s quickly recap the history of Wi-Fi. As we know, it all started with 2.4GHz Wi-Fi. But why exactly in this band? Governments own the overall radio spectrum
and grant licenses to organizations that need them. Governments sell these licenses at high prices. In recent years, they have made billions with
new mobile communication frequencies. But for 2.4GHz, we do not need to pay for
a license. Why is that? Because 2.4GHz is a so-called “ISM” band. Why did they give away such valuable space
for free? This decision was made by the FCC in 1985
when these high frequencies were hardly used for communication because equipment was extremely
expensive. Back then, only one relatively cheap device
was able to produce 2.4GHz: Microwave ovens. Why did they use this band? Because signals on this frequency heat water
with high efficiency. And food contains lots of water. The FCC feared many interferences created
by these microwave ovens. So they decided that nobody was interested
in buying communication frequencies in this band. That is why we got free access to this “junk”
band. And from there, everything started. A similar thing happened with the 60GHz band. This time, the reason was not water, it was
oxygen. Oxygen has its highest attenuation right at
60GHz. So, in plain air, these signals do not travel
far. In 2003, when the decision was made, nearly
no equipment was available for 60GHz. So, the FCC decided with a similar pattern:
A “useless” band on an extremely high frequency cannot be sold. So they gave it for free to the public. But now, we are in 2023. Oxygen still has high absorption, but now
communication devices are available for reasonable prices. And because nearly nobody uses this band,
we do not experience interference as in the 2.4 or 5.8GHz band. Cool. When my colleague Peter told me that these
devices are legally available, I wanted to try them. And here they are: Two Mikrotik Cube 60 Pro
ac. They work on 60GHz and can be used to replace
Ethernet cables because their maximum rated speed is 1Gbit/s. Unbelievable. And more to come: They claim a 2.4km range! Even harder to believe. But there are some small prints: Only with
channel 5 support. Without, it should work up to 1km. I found no information on this secret “channel
5 support”. But I have a suspicion. Later more. The first question is: Why are such high data
rates possible? We all know that the bigger the bandwidth,
the higher the possible transfer speed. Between 60 and 70MHz, only 10MHz bandwidth
is available. Between 60 and 70GHz, there is 1000x more
usable bandwidth. The higher the frequency, the more bandwidth
is available. Simple. 2.4GHz Wi-Fi only uses 20MHz channels. The channels on the 60GHz band are 2.1 GHz
wide. Yes, you heard right: One channel has the
same bandwidth as all other radios below 2.1GHz, including FM stations and mobile phones. There are four such channels available for
most countries. The US allows two more, channels 5 and 6. The 5.8GHz band is in between the 2.4 and
the 60GHz band. With its recently added 6 GHz spectrum, it
offers speed and capacity for many participants. Unfortunately, this also results in interference
in congested areas. There is another huge problem with the 5.8GHz
band: These frequencies are used by weather radars. And because these radars were first, all 5.8
GHz devices have built-in procedures for “Detect and avoid”, “Listen Before Talk”, and
“Dynamic Frequency Selection”. Such connections are sometimes slow at startup
and unreliable during operation, particularly outdoors. They can immediately stop if an unknown signal
is detected. BTW, some military radar systems work on the
“G-band” and have ranges of more than 100km. Not bad for them. Not good if your 5.8GHz link has to stop because
of such signals. So, the 60GHz band seems to be a good alternative
for outdoors. Extremely fast without interference, right? Unfortunately, not. Rain and snowfall can interfere and reduce
its speed or maximum distance. As we later will see, these Mikrotik units
take this into account. Enough theory. Now comes the test where the rubber meets
the road. I ordered these two 60GHz cubes for 130 Euros
each. But before we can use them, we have to do
some setup. I leave a link in the description to the only
video I found. It is in Dutch, but you should be able to
follow it. Because I do not know what this mysterious
“channel 5 support” is, I decided to go for a slightly shorter distance. Still very far, if you ask me. I found this place with a line of sight to
the window of my radio room. I mounted one of the devices in my window
and connected it to the home network. With the second cube on a tripod, a PC, a
LiFePo4 battery, and a 24V boost converter, I drove and walked to this cozy fireplace
on the other side of our valley. Distance: 1.5km. After the setup, I tried to get a working
link. And really, after turning the device toward
my home, I got a connection. Unfortunately, with a data rate below 100Mb/s. Not bad, but less than expected. After investigating, I found the reason: As
said before, these devices have a backup for heavy rain or snowfall. In addition to the 60GHz radios, they have
built-in 5.8GHz radios with automatic switchover. Incredible for this price! So this happened: When the connection did
not work on 60GHz, the devices automatically switched to 5.8 GHz with a much lower speed. At least, these small and easy-to-hide devices
are good for a 1.5km connection on 5.8 GHz. But as you know, on this channel, we want
more! I knew from the datasheet that the opening
angle of these devices is only a few degrees. So the alignment has to be pretty exact. But I had nobody to adjust the device on the
other side. Being an engineer, I found a solution: I went
home, put binoculars on top of the cube, and checked the direction. And really, it was pretty wrong. So my tip: Use binoculars for an initial setup
and place one person at each station to do the small adjustments. Before we continue, let’s have a quick look
at the output power of these devices. The allowed maximum EIRP is 43dBm or 20W. Frequent viewers remember from my recent presence
detection radar video that creating high output power on these high frequencies is still expensive. And consumes a lot of energy. Fortunately, the 60 GHz wavelength is only
5mm. So, antennas with lots of gain are quite small. These antennas get the gain by focusing all
energy to a very small opening angle, like a torch. If these antennas had a gain of, let’s say,
30dB, the transmitter needs 1000 times less power. In addition, the receiving signal is amplified
by the same factor. Very important for the huge bandwidth of 2.1
GHz! But is that gain sufficient to cut through
the high oxygen attenuation? I was confident that the bad alignment was
the reason for the non-functioning of the 60GHz link. So I carried the equipment a second time to
the fireplace. And really, after aligning the cube with the
binoculars, I got a 60GHz connection! And I discovered another function: The user
interface shows how good your antenna alignment is. Do not ask me how they do it, but it works. If you have a second person on the other side,
a perfect alignment is easy. The speed was only around 430Mb/s, not the
promised 1Gb/s. Looking at the raw data, I saw the reason:
Because of the distance and the weak signal, many retransmissions were needed. The rain also did not help. The raw data rate was more than 1.2Gbit/s
to get a 430Mb/s net data rate. Still not bad. And maybe with a perfect alignment on the
other side, it would be possible to reach the maximum even across 1.5km. Because I remembered the problem of the oxygen
attenuation, I changed to channel 4 for the second test. The further away from the maximum oxygen attenuation,
the better. And this might be the secret behind “Channel
5 support”. Channel 5 is probably a good compromise. It is away from the oxygen attenuation losses. And not at the top end of the available spectrum,
where the device probably has some additional losses. But, living in Switzerland, I cannot tell
you if this is the truth behind this small print. Maybe you know more? Or you live in the US, where you are allowed
to use channels 5 and 6. Then, you can test and report back. Now the important question: Where can you
use such devices? First, they look very much like a camera and,
therefore, are nearly invisible. So, for any outdoor Wi-Fi connection, they
are sometimes better suited than the typical 5.8GHz dishes. Also, they do not suffer from interferences. And, of course, if you need speed, this is
the perfect solution. And who does not want speed? They are optimal for point-to-point connections. But you also get devices with bigger opening
angles for point-to-multipoint nets. These devices have lower gain and a shorter
range. All-in-all, a fascinating technology! With a low price tag for two built-in radios,
including failover. Let’s see how this Wi-Gig technology will
develop in the future. This was all for today. As always, you find all the relevant links
in the description. I hope this video was useful or at least interesting
for you. If true, please consider supporting the channel
to secure its future existence. Thank you! Bye
