In this lesson,
we're going to talk about microwave connections,
we'll not talk about the kind
that you reheat your frozen burrito with.
Instead, we're talking about microwave links.
And a microwave link is a communication system
that uses a beam of radio waves
in the microwave frequency band
to transmit information between two fixed locations.
When we're talking about the microwave frequency range,
we're really talking about frequencies
in the range of 300 megahertz to 300 gigahertz,
which includes the UHF or ultra high frequency range,
SHF or super high frequency range,
and EHF, the extremely high frequency range.
Now, there are lots of places
that are going to use microwaves for their connections.
It's quite popular for large college campuses,
for example, to connect portions of their network
over microwave antennas located
on the top of their buildings,
but some small businesses can use these, too.
In fact, when I had my office down in Puerto Rico,
we used our main internet connection as a microwave link
between the antenna on our roof of our building
and the roof of the hospital in our city.
Our connection would reach the antenna
at the top of the hospital and it was combined
with other businesses from around our city
who had a similar setup,
and then it would be sent across the island
to our internet service provider,
using their fiber connection.
Using the microwave link, we could get speeds
of up to one gigabit per second to our offices,
depending on how much we wanted to pay per month
to our internet service provider.
As you can see, microwaves can provide you with a very,
very fast connection point,
using point-to-point connections between two places,
but they are limited to what they can see
using a line of sight connection.
So when they talk about line of sight,
these are the two antennas have to point at each other
and they have to be able to see each other.
Because of this visual horizon
and the curvature of the earth though,
this normally means you're going to have a distance limitation
of around 40 miles or 64 kilometers.
And this is the exact reason
why our internet service provider leased an antenna space
on the top of the hospital in our town
to place the receiving antenna.
That hospital was actually on the top of a hill
and it was one of the tallest buildings around,
so most of the buildings in our city could get a direct line
of sight to the top of the hospital
if they were within about 20 to 30 miles of it,
and this made it an ideal place to install their antenna.
Now this allowed the internet service provider
to pay for one fiber connection from the hospital
and connect all their microwave customers back
to the high speed fiber connection
to get them out to the internet.
And that's really the benefit
of using one of these microwave point-to-point connections.
Now, when microwave connections were first being sold
to consumers, they marketed under the name WiMAX,
but really it's under the standard IEEE 802.16
when you're dealing with microwave access,
instead of the Wi-Fi standard of 802.11.
WiMAX was just an abbreviation
for Worldwide Interoperability for Microwave Access.
Microwave is a good alternative for cellular and DSL service
because it does provide faster speeds,
but it is more expensive than just getting a cable modem
from your local internet service provider.
Also, microwave access does require an antenna
to be installed on your roof of your home or office.
This usually requires a professional to install it for you.
Microwave connections are considered
to be a wireless fixed location service
because you're going to have to have a larger antenna
and a larger radio to pick up that signal properly
than you would using just a cellular modem.
WiMAX was popular for a very long time
because of its high speeds in comparison
to other wireless technologies like cellular and satellite.
But with the introduction of 4G and 5G cellular,
WiMAX does tend to be in the same range,
but the cellular modems are much easier to install
because they don't require mounting
of special antennas on your roof,
and they can be moved from location to location easier.
For this reason, WiMAX and Microwave
is beginning to lose a lot of popularity
as a direct to consumer internet service,
but you may still see it used a lot
for internal WAN connections such as in business parks
or college campuses
where you can't run fibers easily between two buildings.
So it is still something you should be aware of
and be able to work on as a network technician.