Outdoor Wireless Link
I
studied IT engineer in Extremadura where I had to take lots of maths
subjects. I also took subjects about application development and
operating systems. All
of them were interesting. However, today, I’m mainly working with
networking and security. I only took one subject about security, it
was optional, and I also took two subjects about networking, but I
think it’s
enough to take the plunge to do networking and security projects
because we have to keep studying day in day out.
For instance, I didn’t take any subject about Wireless
Links
but I had to study how they work and how to configure them.
I’ve
already
had
the luck of working on two projects about Wireless Links. One of them
was to broadcast
free WiFi in a small town and the other one was to connect several
buildings in the middle of the countryside. Two interesting projects.
These
days, I’m working on a new project to connect two buildings because
there is no Internet connectivity in one of them. Therefore, I
have to plan an Outdoor
Wireless Link
where I have to take into account the distance between buildings as
well as
the Line of Sight (LoS), Fresnel zone, fade margin, frequency,
channel width, signal-to-noise
ratio (SNR), etc.
Outdoor Wireless Link |
There
are software which are
very useful for planning outdoor wireless links such as Radio
Mobile
and AirLink.
These
software help us to
choose features such as frequency,
channel width, etc. For instance, we’ll have to choose a free
frequency or a licensed frequency. If we want to use a free frequency
in 2,4 GHz or 5 GHz, we’ll have to configure an EIRP accordingly to
the country where we are going to install the wireless link. However,
if we want to use a licensed frequency, we’ll have to require that
license to the government.
AirLink |
These
software also help us to know if there is Line
of Sight
(LoS)
between sites. This is very important because LoS
allow us to know if the wireless link will be successful. However, if
there is no LoS, we won’t know the wireless link performance during
the planning phase. For instance, if there is a partial obstruction
with a mountain, there could be attenuation, reflection or
refraction. It’s
also important to highlight how low frequencies can
propagate to great distances with little attenuation.
Line of Sight - LoS |
When
we are going to choose an access point to install a wireless link, we
also
have
to take into account what
is the network going to be used for because VoIP
traffic has not the same network requirements than Data traffic. For
instance, VoIP traffic needs 50 PPS while Video streaming traffic
needs 1000 PPS.
TCP-IP Packet |
To
sum up, there are lots of technical features we should know before
installing an outdoor wireless link. The Line of Sight, frequencies,
channel width, etc should be studied carefully to install a wireless
link successfully. Therefore, if we
want an efficient and reliable wireless link, we’ll
have to study these concepts at University or by ourselves.
Regards
my friends. Drop me a line with the first
thing you are thinking!
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