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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