Instructor: Our next wireless technology
we need to discuss is known as microwave,
but not the kind you reheat your frozen burrito with.
Now, a microwave link is a communication system
that uses a beam of radio waves
in the microwave frequency range
to transmit information between two fixed locations.
When we're talking about the microwave frequency range,
we're talking about frequencies
in the range of 300 megahertz to 300 gigahertz,
which includes UHF, ultra high frequency,
SHF, super high frequency,
and EHF, extremely high frequency.
Now, there's a lot of places
that use microwave for their connections.
It's actually quite popular for large college campuses
to be able to connect different portions of their network
over microwave antennas
located at the top of their buildings
instead of trying to run fiber
between all those different buildings.
Now, small businesses can also use microwave technology.
In fact, the main internet connection
that I have in my office in Puerto Rico is a microwave link.
I have an antenna on the roof of our building
and that connects to an antenna on the roof of the hospital
in the center of our city.
Now, once the connection reaches the antenna
at the top of the hospital,
it's combined with all the other businesses around our city
that have a similar setup,
and then all of that is sent across the island
to our internet service provider
using a fiber connection they have from the hospital
back to our ISP.
Using this microwave link,
we can have speeds up to one gigabit per second
to our offices depending on how much we want to pay per month
to our internet service provider.
As you can see, microwave technology can provide
with a super fast point-to-point connection
between two places, but there is a limitation.
Both antennas must maintain what is known as line of sight.
You see, the two antennas that make up this connection
have to be able to actually see each other.
Due to the visual horizon and the curvature of the Earth,
this is normally going to create a distance limitation
of about 40 miles or 64 kilometers.
This is one of the reasons why our internet service provider
has actually leased the rooftop of the hospital in our town
to place the receiving antennas.
This is because I can't see from my house
all the way back to the ISP 120 miles across the island.
So I connect up to the hospital
and then they pass it over a fiber line over to the ISP.
This is because we're in a pretty hilly area
and so the hospital
is one of the tallest buildings in our city.
And so most of the buildings and most of the offices
can get a direct line of sight from them
to the hospital's roof
if they're within 20 or 30 miles of the hospital.
Therefore, this became an ideal place
to install those antennas.
This allows the internet service provider
to pay for one fiber connection to that hospital
and they connect all the microwave customers
to that high speed fiber instead of having to run fiber
directly to everybody's house or everybody's office.
Now, when microwave connections
were first being sold to consumers,
it started being marketed under the term WiMAX
instead of WiFi.
Now, WiMAX is really IEEE 802.16
when you're dealing with microwave access
instead of the 802.11 standard that's used by WiFi.
WiMAX is an abbreviation
for Worldwide Interoperability for Microwave Access.
Microwave is actually a really good alternative
for cellular or DSL service
because it provides faster speeds,
but it is usually going to cost you more
than just getting a cable modem
from your local internet service provider.
Also, microwave access does require an antenna
to be installed on the roof of your home or office
and that requires a professional to get up there
and install it for you.
Microwave connections are considered
a wireless fixed location service
because you're going to have a larger antenna
and a larger radio to pick up that signal properly,
but it does provide you
with some really, really nice speeds.
Now, here, you can see how WiMAX
compares to traditional sailor speeds like GSM which is 2G,
UMTS which is 3G, HSPA which is 3.5G,
and WiMAX is faster than all of these.
But since the addition of 4G and 5G
mid band cellular modems,
WiMAX tends to be in that same speed range,
while the cellular modems are much easier to install
because they don't require
the mounting of special antennas on your roof.
For this reason, WiMAX and microwave
is beginning to lose some popularity
as a direct-to-consumer internet service,
but it is still often used for internal WAN connections,
such as in a business park or a college campus
if you can't run fiber between the buildings easily.