1. Submitted By : Submitted to :
Name : Vikas Mr. Praveen Jain
Roll No. : 52
Reg. No. : CRO0358769
Batch : March’14 Afternoon
Timings : 1:30 PM – 6:00 PM
Section : B
2.
3. We take this opportunity to express our profound gratitude and deep regards to our
teachers for their exemplary guidance and monitoring.
On the very outset of this project, we would like to extend our sincere & heartfelt
obligation towards all the personages who have helped us in this endeavour. Without
their active guidance, help, cooperation & encouragement, we would not have made
headway in the project.
Lastly, we thank Almighty, our parents and friends for their constant encouragement
without which this project would not have been possible.
4. • INTRODUCTION
• HISTORY
• TYPES OF SATELLITE COMMUNICATION
• ADVANTAGES OF SATELLITE COMMUNICATION
• DISADVANTAGES OF SATELLITE COMMUNICATION
• COMPONENTS OF SATELLITE
• HOW DO SATELLITES WORK?
• SATELLITES POWER SYSTEMS
• APPLICATIONS OF SATELLITE COMMUNICATION
• DEVELOPMENT OF SATELLITE COMMUNICATION
• ASTROLINK & CYBERSTAR
5. • Satellites are specifically made for telecommunication purpose. They are used for
mobile applications such as communication to ships, vehicles, planes, hand-held
terminals And for TV & Radio broadcasting.
• They are responsible for providing these services to an assigned region (area) on
the earth. The power and bandwidth of these satellites depend upon the
preferred size of the footprint, complexity of the traffic control protocol schemes
and the cost of ground stations.
• A satellite works most efficiently when the transmissions are focused with a
desired area. When the area is focused, then the emissions don't go outside that
designated area and thus minimizing the interference to the other systems. This
leads more efficient spectrum usage.
6. • Satellite’s antenna patterns play an important role and must be designed to best
cover the designated geographical area (which is generally irregular in shape).
Satellites should be designed by keeping in mind its usability for short and long
term effects throughout its life time.
• The earth station should be in a position to control the satellite if it drifts from its
orbit it is subjected to any kind of drag from the external forces.
7. • Satellite Communication began in October 1957 with the launch by the
USSR a Small Satellite called Sputnik 1(4.10.1957).
• 3.11.1957 Sputnik 2 with LAIKA.
• 12.4.1961 VOSTOK 1 with JURI GAGARIN.
• First true communication satellites (telestar 1 & 2) were launched in July
1962 & may 1963.
8. •10/1964 Syncom 2 : first geo satellite , 7.1/1.8 GHZ (one TV-channel &
several 2- way telephone connection).
•1987 TVSAT : First DBS-satellite(direct broadcast satellite, Television-
Broadcasts directly to home).
SPUTNIK 1
9. There are broadly three types of satellites on the basis of orbits that are used for
communication:
• Geostationary or geosynchronous earth orbit (GEO)
• Low Earth Orbit (LEO) satellites
• Medium Earth Orbit (MEO) satellites
GEOSTATIONARY OR GEOSYNCHRONOUS EARTH ORBIT (GEO)
• GEO satellites are synchronous with respect to earth. Looking from a fixed point
from Earth, these satellites appear to be stationary.
• These satellites are placed in the space in such a way that only three satellites are
sufficient to provide connection throughout the surface of the Earth (that is; their
footprint is covering almost 1/3rd of the Earth).
• The orbit of these satellites is circular.Eg:KALPANA-1 ,a weather satellite launched
by ISRO in 12 September , 2002
10. LOW EARTH ORBIT (LEO) SATELLITES
• These satellites are placed 500-1500 kms above the surface of the earth. As LEOs
circulate on a lower orbit, hence they exhibit a much shorter period that is 95 to
120 minutes.
• LEO systems try to ensure a high elevation for every spot on earth to provide a
high quality communication link.
• Each LEO satellite will only be visible from the earth for around ten minutes.
Eg:ENVISAT is one example of an Earth observation satellite that makes use of this
particular type of LEO.
• These satellites are mainly used in remote sensing an providing mobile
communication services (due to lower latency) due to simplicity and cost
effectiveness.
11. • MEOs can be positioned somewhere between LEOs
and GEOs, both in terms of their orbit and due to their
advantages and disadvantages. Using orbits around
10,000 km, the system only requires a dozen satellites
which is more than a GEO system, but much less than
a LEO system.
• These satellites move more slowly relative to the
earth's rotation allowing a simpler system design
(satellite periods are about six hours).
• Depending on the inclination, a MEO can cover larger
populations, so requiring fewer handovers. Eg: Telstar
1, an experimental satellite launched in 1962, orbits in
MEO.
12.
13. • The coverage area of a satellite greatly exceeds that of a
terrestrial system.
• Transmission cost of satellite is independent of the
distance from the center of the coverage area.
• Satellite to satellite communication is very precise.
• Higher Bandwidths are available for use.
14. • Launching satellites into orbit is costly.
• Satellite bandwidth is gradually becoming used
up.
• There is a large propagation delay in satellite
communication than in terrestrial
communication.
15. • Command Antenna
• Communication Antenna
• Solar Cells
• Batteries
• Radio Receivers &Transmitters
• Rocket Fuel
• Main pocket motor
• Rocket Thrusters
16. A Satellite is basically a self-contained communications system
with the ability to receive signals from Earth and to retransmit
those signals back with the use of a transponder.
17. • The main components of a satellite consist of the
communications system, which includes the antennas and
transponders that receive and retransmit signals, the power
system, which includes the solar panels that provide power,
and the propulsion system, which includes the rockets that
propel the satellite.
• A satellite has thrusters that are fired occasionally to make
adjustments in its position.
• The maintenance of a satellite’s orbital position is called
“station keeping,” and the corrections made by using the
satellite’s thrusters are called “attitude control.”
18. • The Transponder (short-for Transmitter-responder) is the
“BRAIN” of the satellite that provides connection between the
satellite’s Receive and Transmit antennas.
• Satellites can have 12 to 96 transponders plus spares,
depending on the size of the satellite.
19. • Main source of power is solar cell panels - new solar cells are
increasingly efficient
• The solar cell system is backed up by battery system that
provides energy during solar eclipses and other periods of
outages
• Typical power levels of 2 to 5 KWs for Fixed Satellite Systems
and 10 to 12 KWs for Mobile and Broadcast Satellite Systems.
• Batteries: latest battery technology is represented by Lithium
Ion systems that can provide a greater power density for
longer periods of time and survive a greater depth of
discharge
20. • Telephone Calls : The first and historically most important
application for communications was long distance telephony. The
fixed Public Switched Transfer Network relays telephone calls from land
line telephones to an earth station, where they are then transmitted to a
geostationary satellite. The downlink follows an analogous path . Satellites
also play an important role in delivering programming to cell phones and
other mobile devices, such as personal digital assistants and laptops .
• TV Broadcasting : The most familiar use of satellites is television
broadcasting. TV satellites deliver hundreds of television channels every day
throughout the world. They are even used to supply television signals to
terrestrial transmitters or cable-head end stations for further distribution to the
home, or to exchange signals between television studios. The bandwidth
required to transmit multiple programmes at the same time can easily be
provided using satellites.
21. Radio :Satellite radio offers audio services in some countries, notably the
United States. Mobile services allow listeners to roam a continent, listening to
the same audio programming anywhere.
A satellite radio or subscription radio (SR) is a digital radio signal that is
broadcast by a communications satellite, which covers a much wider
geographical range than terrestrial radio signals.
Internet Access :After the 1990s, satellite communication technology
has been used as a means to connect to the Internet via broadband data
connections. This can be very useful for users who are located in remote areas,
and cannot access a broadband connection, or require high availability of
services.
22. • Satellite Phones & Emergency Communication:
When terrestrial communications fail due to natural disasters , they provide
communication . They serve civilian’s in rural areas where communication
network dos not exist by providing telephony service. Satellite phones can be
accomplished in many different ways. On larger scale often there will be local
telephone system in the isolated area with a link to a telephone system in a main
land area.
• Military Sector : Satellite Communication provides robust and
sophisticated secure communications system for the military . Examples of
military systems that use communication satellites are the MILSTAR , the DSCS ,
and the FLTSATCOM of the United States, NATO satellites, United Kingdom
satellites (for instance Skynet) , and satellites of the former Soviet Union.. India
has launched its first Military Communication satellite GSAT-7.
23. • As earlier discussed, the actual journey into space
began October 4, 1957, when the Soviet Union
launched Sputnik 1, the world's first orbital spacecraft,
which orbited the world for three months.
• A month later the Soviets launched Sputnik 2 and its
passenger Laika, a dog.
• This further led to many other significant
developments in the field of satellite communication.
24. Satellite Launched Nation
Sputnik 1 October 4, 1957 Soviet Union
Project SCORE December 18, 1958 USA
TIROS 1 April 1, 1960 USA
Echo 1 August 12, 1960 USA
Courier 1B October 4, 1960 USA
OSCAR 1 December 12, 1961 USA
Teslstar 1 July 10, 1962 USA
Relay 1 December 13, 1962 USA
Syncom 2 July 16, 1963 USA
Syncom 3 August 19, 1964 USA
25. • Future communication satellites will have
more onboard processing capabilities, more
power, and larger-aperture antennas that
will enable satellites to handle more
bandwidth.
• Further improvements in satellites’
propulsion and power systems will increase
their service life to 20 – 30 years from the
current 10 – 15 years.
26. ASTROLINK
• Lockheed martin’s proposed astrolink system will have nine geostationary
satellite in five orbit locations.
• Each satellite total capacity is 7.7 Gab/s. by placing two satellite at the same
location and operating them with orthogonal polarizations, a total capacity of
15 Gab/s is achieved over America.
• Cross-links between satellite operating at 60 GHz provides a means of routing
traffic round the globe ;each link has a capacity of 1 Gab/s.
CYBERSTAR
• Loral’s proposed cyber star system represents a lower cost, less risky approach
to the market.
• Loral proposes to launch just three geostationary satellite positioned to reach
the world’s largest population centers.
27. company system orbit coverage
Satellite
capacity(
Gab/s)
Intersatelite
link
Onboard
switching
Lockheed
martin
Astrolink GEO Global 7.7 1 Gb/s FPS
Loral Cyberstar GEO
Limited
global
4.9 1 Gb/s BBS
Hughes
Galaxy/
spaceway
GEO global 4.4 1 Gb/s BBS
