This presentation discusses freespace optical communication (FSO), which transmits modulated beams of light through the atmosphere for broadband communications. It provides a brief history of FSO, describes how FSO works by converting network traffic to light pulses, and lists its advantages like low cost, high security, and immunity to electromagnetic interference. The presentation also outlines FSO's applications like metro networks and last mile access, and discusses its disadvantages such as reliance on line of sight and susceptibility to atmospheric conditions.

1. PRESENTATION
ON
“ FREESPACEOPTICALCOMMUNICATION”
Submittedby:
VIKASH KUMAR
REG NO-17304025
DEPARTMENTOFELECTRONICS ENGINEERING

2. Outline
 Introduction
 History
 Working
 Advantages
 Disadvantages
 Applications
 Security
 Conclusion
 References

3. Introduction
 FSO is a line-of-sight (LOS) technology that transmits a
modulated beam of visible or infrared light through the
atmosphere forbroadband communications.
 FSO technology delivers cost-effective optical wireless
connectivity, power efficient, and a faster return on
investment (ROI) for Enterprises and Mobile Carriers.
 Of high usage where physical connections are impractical
due to high costs and other considerations.

4. History
 In 1880, AlexanderGraham Bellinvented the ‘photo-phone’
 The invention of lasers In the 1960s, revolutionized free space
optics.
 Germany, France and Japan made significant advancements
in free space optics for satellite communications.
 Military organizationsespecially were interested and forced
some developments.

5. Why FSO??
 Increasing
demand for high
bandwidth in
metro networks
 Last mile bottleneck
:Copper-based
connections limits
speed to an average of
around 12Mbps–
generally the slowest
link in the chain.
 Digging, delays and
associated costs to lay
fiber often make it
economically
prohibitive.
 RF-based networks require
immense capital investments
to acquire spectrum license.
Also bandwidth is limited to
622 Mbps
So FSO is
used as an
alternative!!

6. Working
Network traffic converted
into pulses of invisiblelight
representing 1’s and0’s.
Transmitter projects the
carefully aimed light
pulses into theair.
Reverse direction
data transported
the same way.
A receiver at the other
end of the link collectsthe
light using lenses and/or
mirrors.
Received signal converted
back into fiber or copper
and connected to the
network.
Anything that can be done in fiber can be done with FSO.

7. Block Diagram
SOURCE
DESTINATION DEMODULATOR AMPLIFIER
PHOTO RECEIVE
OPTICS
TRANSMIT
OPTICS
DRIVER
LASER
MODULATOR
ATMOSPHERIC
CHANNEL
DETECTOR
Receiver
DIODE
Transmitter

8. FSOand Other Technologies
Coaxialcable Satellite OpticalFibre FreeSpaceoptics
Transmission
speed
500Mbps 90Mbps 100Mbps to
100Gbps
Varies
Ease of
installation
Moderate Difficult Difficult Moderate
Cost Moderate Moderate (not including
cost of satellite)
High Moderate
Maintenance
difficulty
Moderate Low Low Low
SkillsRequiredto
install
Moderate High High Moderate
Applications Computer networks long distances Point-to-point Between buildings
Advantages Lesssusceptible to
interference
Speed, availability Not susceptibleto
EMI
Price/ performance
Disadvantages Bulky, difficult to work
with
Propagation delay Difficult to
terminate
Canbe intercepted

9. Applications
 Metro Area Network (MAN)
 Last Mile Access
 Enterprise connectivity
 Fiber backup
 Backhaul
 Service acceleration
 SpaceApplications/Extraterrestrial(esp. in military)
 CCTV
 Video conferencing

10. Advantages
 Installation cost is very low as compared to layingFiber
 Highly secure transmission possible
 Unregulated Spectrum
 Low Power Consumption
 Easeofinstallation
 License-free long-range operation
 Immunity to electromagneticinterference
 Speed: high bit rates and low biterror rates

11. Disadvantages
 High Launch Power represents eye hazard.
 Physical obstruction
 Atmospheric barriers
 SNRcan vary significantly with the distance and the ambient noise
 Low Power Sourcerequires high sensitive receivers.
 If the sun goes exactly behind the transmitter, it can swamp the
signal.

12. SECURITY
FSO laser beams cannot be detected with spectrum analyzers or
RF meters.
FSO laser transmissions are optical and travel along a line of sight
path that cannot be intercepted easily.
The laser beams generated by FSO systems are narrow and
invisible, making them harder to find and even harder to intercept
and crack.
Data can be transmitted over an encrypted connection adding to the
degree of security available in FSO network transmissions.

13. Conclusion
 For future short-range applications, optical wireless communications
present a viable and promising supplemental technology to radio
wireless systemsand optical fiber.
 It provides a low cost, rapidly deployable method of gaining access to
fiber-quality connections and provides the lowest cost transmission
capacity in the broadband industry saving substantial up-front capital
investments.
 Can be installed for as little as one-tenth of the cost of laying fiber cable,
and about half as much as comparable microwave/RF wireless systems
thus eliminating the need to buy expensive spectrum, which further
distinguishes it from fixedwireless technologies.

14. References
[1] www.opticsinfobase.orgoefulltext.cfmuri=oe-19-26-B56&id=224428
[2] www.pi-usa.us/products/images/300x250_images/S-334-Red-Beams.jpg
[3] www.pi-usa.us/products/images/300x250_images/S-334-Red-Beams.jpg
[4] image.slidesharecdn.com/introductiontofsotechnology-1216024918992120-
8/95/introduction-to-fso-technology-3-728.jpg?cb=1360750423
[5] image.slidesharecdn.com/freespaceoptics-140721105157- phpapp02/95/free-
space-optics-communication-9-638.jpg?cb=1405957976
[6] www.optica.ru/EN/lant3a.jpg.
[7] http://cictr.ee.psu.edu/research/pcs/index_files/image010.jpg