GeoDesy FSO GD series - Manual (Page 8)

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GeoDesy Kft. Telefon: 06-1-481-2050
H-1116 Budapest, Kondorfa str. 6-8. Fax.: 06-1-481-2049
E-mail: info@geodesy-fso.
2 Introduction
2.1 What is FSO?
FSO is free space optics provides point-point broadband communications using
Laser Light as the transmission medium.
FSO is a state of art data communication method which is based on a very old
communication solution. Ancient Chinese developed a protection system against the
Mongol tribes, building watchtowers within the line of site to other towers. And as
soon as the towers saw some hostile sign on the horizon they use they shield to
reflect the sun to the remote towers. In this way the area could be prepared against
the attack in a very short period of time.
In the ancient times for this communication use the mirror
as a transmitter and the sunlight was the light source, and
the receiver was the remote guard’s eye. This basic
signalling method was developed later into up
communication device which used „line coding”. This
allowed the guards to tell the number of enemy, or the
direction they are coming from.
Current
FSO systems use a laser-diode as a light source,
and a receptor diode (photo diode) to receive the signals
coming from the laser diode from the transmitter side. But
the basic elements are still the same: line of site between
the communication nodes, and individual line coding. It is all about performance.
GeoDesy-FSO offers FSO systems with the highest power budget available on
the market.
Why is it important?
Because of in the ancient Chinese times, the rain, the fog, or even the cloudy
weather, could impact the operation of the whole system.
In the
FSO units, comprising light source and receiver the cloud problem was
solved, but development conditions still can impair
performance. To go throw the rain, the fog, or snow you
need more and more power to be seen from the remote
side. Achievable power levels are limited by a number of
factors including eye safety.
In this way there is no other choice to see more than
„training the eye”. Making the receiver more and more
sensitive to sense delight emitted from the remote side.
GeoDesy-FSO offers high transmit power and also