Free-space optical communication is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. It is a technology that can be installed license-free worldwide and can be installed in less than a day. A technology that offers a fast, high ROI. There is no Frequency License Required in it.

1. Naveed Qurban
BS - Telecommunication
1428 – 215204
FREE SPACE OPTICS

2. What Is Free Space Optics?
Free Space Optics was first invented by Alexander
Graham Bell in 1880. He called his invention the
Photophone. He was able to transmit sound on a
beam of light with the help of mirrors and sunlight.
Invention of Lasers revolutionize FSO in 1960s.

3. DEFINITION
• Free Space Optics (FSO) is a wireless
technology that transmits data via laser
beams.
• It uses light to transmit data between
buildings that have clear a line of sight
(LoS).

4. LINE OF SIGHT (LOS)
It is a type of propagation that can transmit and
receive data only where transmit and receive
stations are in view of each other without any sort
of an obstacle between them.

5. PRINCIPLE
• FSO works on the same principle as
Infrared TV remote, Wireless Keyboard,
Wireless Palm devices.
• FSO transmits invisible, eye safe light beam
from one telescope to another using low
power infrared lasers in Tera Hertz (THz).
• It is full duplex having bi-directional
capability.
• In early days both Transmitters and
Receivers are used separately but in modern
era it is replaced by Transceivers.

6. WHY WE USE FSO?
• FSO can send large amount of data (voice
and video data).
• We can send the data at the speed of 2.5GB
per second approximately.
• It can easily transmit data at a distance of
around 4KM.
• The cost of FSO is less compared to fiber
optics cables.
• The FSO system can be installed quickly
comparatively to fiber optics.

7. WHY WE USE FSO?
• No need to get a license, the spectrum is
used unlicensed worldwide.
• As it uses light so there is no RF
interference (Radio Frequency
Interference).

8. HOW FSO WORKS?
The apparatus includes in FSO are
transceiver, lens, telescope. Some also
add motors, voice coils,
Microelectromechanical systems
(MEMS) for tracking purpose.

9. HOW FSO WORKS?

10. FSO NETWORK DIAGRAM

12. COMPARISON OF FSO

13. FSO ADVANTAGES
• Requires no RF spectrum licensing.
• It is highly secure due to the high
directionality and narrowness of the beam.
• Easy and speedy installation.
• Does not effect with RF interference
(Electromagnetic Interference).
• It has high bit rates low bit error rates.

14. FSO ADVANTAGES
• Lower costs as compared to fiber networks
and others alike mediums.
• Transmission of optical beam is done in
air. Hence, transmission is having speed of
light.

15. FSO Disadvantages
• Its transmission is effected during Foggy,
Rain, Snow weather.
• If the sun goes exactly behind the
transmitter, it can swamp the signal.
• Its transmission rate is weather dependent.
• Distance is limited.
• Flying birds can temporarily block a
single beam, but this tends to cause only
short interruptions, and transmissions are
easily and automatically resumed.

16. FSO APPLICATIONS
• It is mainly used for communication
Military (Army, Navy & Airforce)
operations.
• Its is used to communicate b/w space
crafts. As it is out of atmosphere so there is
less chance of any distortion of signal.
• CCTV security applications.

17. FSO APPLICATIONS
• Bridging WAN Access: FSO is beneficial in
WAN where it supports high speed data
services for mobile users.
• FSO systems are easily installable. This
feature makes it applicable for interconnecting
LAN segments to connect two buildings or
other property.

18. CONCLUSION
FSO offers many advantages over
existing techniques which can be either
optical or radio or microwave. Less cost
and time to setup are the main attraction
of FSO system. Optical equipment can
be used in FSO system with some
modification. Merits of FSO
communication system and its
application area make it a hot technology
but there are some problems too as
discussed above.

19. CONCLUSION
Many studies are going in this
perspective to minimize errors within
FSO. This can lead to the improvement
of the system. Different techniques like
OFDM-FSO, WDM-FSO based system
are new approach to improve the system
performance with high speed and
enhance the distance so that the demerits
of FSO system can be reduced to a
minimum level.

20. Thank You