EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
V.R.S. College of Engineering and Technology
(Reaccredited by NAAC and an ISO 9001:2008 Recertified Institution)
Subject Name : SATELLITE COMMUNICATION
Subject code : EC8094
Regulation : 2017
Year/Semester : IV/VIII
Branch : ECE
UNIT V
SATELLITE APPLICATIONS
INTELSAT Series, INSAT, VSAT, Mobile satellite services: GSM, GPS, INMARSAT, LEO,
MEO, Satellite Navigational System. GPS Position Location Principles, Differential GPS,
Direct Broadcast satellites (DBS) - Direct to home Broadcast (DTH).
5.1 INTELSAT Series
5.2 INSAT
5.3 VSAT
5.4 Mobile satellite services
5.4.1 GSM
5.4.2 GPS
5.4.3 INMARSAT
5.4.4 LEO
5.4.5 MEO
5.4.6 Satellite Navigational System
5.4.6.1 GPS Position Location Principles
5.4.6.2 Differential GPS
5.5 Direct Broadcast satellites (DBS)
5.6 Direct to home Broadcast (DTH)
5.1 INTELSAT Series, INSAT
1. Explain the types of INTELSAT satellites with respect to basic spacecraft
characteristics and vehicle type. (April 2014)
2. Write about INTELSAT, INSAT and INMARSAT. (Nov/Dec 2012) [Apr/May 2023]
INTELSAT Series
INTELSAT - International Telecommunications Satellite
1
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
,EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• The formation of the international cooperative organization INTELSAT in 1964 paved the
way for the sophistication of satellite systems available today.
• There are other international organizations but none has stood the test of time as well as the
very successful INTELSAT systems, which provide voice, data, and video services.
• INTELSAT covers three main regions- AOR (Atlantic Ocean Region), IOR(Indian Ocean
Region) and POR (Pacific Ocean Region).
INTELSAT I:
• Known as Early Bird, this was launched in 1965 and was the first commercial
communications satellite operating over the Atlantic Ocean.
• It was a cylindrical, spin-stabilized satellite and had two transponders, each with about 30
MHz of bandwidth. The RF transmit power was about 4 W, and the EIRP was 12 to 14
dBW, indicating the antenna was an omni directional type.
• The equivalent isotropic radiated power (EIRP) is the product of power and gain.
• About 600 solar cells provided 45 W of power for all the circuitry.
• It had a capacity of either 240 voice telephone circuits, or one good-quality television
transmission.
• Its designed lifetime is extended to more than three years.
INTELSAT II:
• In 1967, three INTELSAT II satellites were put into operation.
• The first was placed over the Pacific Ocean to extend coverage to the Pacific region.
• The second was placed over the Atlantic Ocean to increase capacity for the Atlantic region,
and the third was also placed over the Pacific Ocean and acted as a spare.
• INTELSAT II was very similar to Early Bird in construction, but with improved channel
capacity.
2
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
,EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• With satellites over the Atlantic and Pacific, two thirds of the world’s area was covered by
communication satellites.
• INTELSAT II was designed to have a lifetime of three years.
INTELSAT III:
• During 1969, three INTELSAT III satellites were launched over the Atlantic, Pacific, and
Indian Oceans.
• This configuration saw the first global satellite coverage as initially proposed by Arthur
Clarke in 1945.
Figure: Coverage of INTELSAT
•
INTELSAT III introduced some new features, such as the despun antenna.
•
INTELSAT III was also the first in the series to use a highly directional antenna.
•
It had a beam width of 19°, which is just 2° more than the 17° requirement for global
coverage.
• The 2° margin was to allow for pointing error.
• The global antenna had a conical shape with a flare angle of 6°, and pointing accuracy was
maintained by controlling the despun motors with infrared sensors that detected the earth’s
horizon.
INTELSAT IV:
• During the period from 1971 to 1975, eight INTELSAT IV satellites were launched, of
which seven reached orbit and provided service.
• Increasing the INTELSAT IV capacity to 4000 telephony channels plus two TV channels
without increasing the bandwidth required some additional frequency reuse ingenuity.
• INTELSAT IV satellites each had twelve transponders of 36-MHz bandwidth, with a 4-
MHz guard band between adjacent transponders.
• The satellites had global coverage antennas and two 4.5° beamwidth spot beam antennas
that were steerable from earth.
3
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
, EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• One of the two spot beams was directed to the east and the other to the west of an ocean
region.
• The objective of the spot beam transmissions was to provide more capacity for the heavier
traffic-generating routes, the spot beam capacity being approximately double the global
beam capacity.
• The shape of the beam could be modified by selecting the appropriate horns for
transmission.
• SCPC systems were first introduced on INTELSAT IV-A to provide more flexibility,
especially for low-traffic (thin) routes.
INTELSAT V:
• New technology employed on INTELSAT V included the use of the 14/11-GHz band.
• Linear polarization was used in this band because it provides better cross-polarization
discrimination at this frequency than does circular polarization.
• It also used three-axis body stabilization for the first time, instead of spin stabilization.
• The solar arrays producing 1228 W (after 10 years in orbit) were on flat panels instead of
around the cylindrical body, and a momentum wheel within the body of the satellite
provided gyroscopic stabilization.
• TDMA was first introduced for use with INTELSAT V.
• INTELSAT V-A uses the spatial and polarization frequency reuse techniques to enhance
bandwidth utilization.
INTELSAT VI:
• Satellite-switched TDMA was introduced for the first time with INTELSAT VI.
• The total available transponder bandwidth is 3330 MHz by using C- and Ku-bands,
orthogonal polarization, and spatial isolation.
• The 6/4-GHz frequencies are reused six times, and the 14/11-GHz frequencies are reused
twice.
• DCME started to have widespread use for more cost-effective voice traffic.
INTELSAT VII:
• The INTELSAT VII/VII-A series of satellites is a high-capacity and versatile fleet of
spacecraft deployed for global service.
• The INTELSAT VII design has 26 C-band and 10 Ku-band transponders that allow 18,000
telephone calls and three color TV broadcasts simultaneously, or up to 90,000 telephone
circuits using DCME.
• INTELSAT VII-A has 26 C-band and 14 Ku-band transponders, providing 22,500
telephone calls and three color TV broadcasts simultaneously, or up to 112,500 telephone
circuits using DCME.
• VII-A also has independently steerable C-band spot beams for better traffic-handling
capability. This satellite upgrades the IDR BER performance from 10–7 to 10–10 under
clear sky conditions.
4
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
V.R.S. College of Engineering and Technology
(Reaccredited by NAAC and an ISO 9001:2008 Recertified Institution)
Subject Name : SATELLITE COMMUNICATION
Subject code : EC8094
Regulation : 2017
Year/Semester : IV/VIII
Branch : ECE
UNIT V
SATELLITE APPLICATIONS
INTELSAT Series, INSAT, VSAT, Mobile satellite services: GSM, GPS, INMARSAT, LEO,
MEO, Satellite Navigational System. GPS Position Location Principles, Differential GPS,
Direct Broadcast satellites (DBS) - Direct to home Broadcast (DTH).
5.1 INTELSAT Series
5.2 INSAT
5.3 VSAT
5.4 Mobile satellite services
5.4.1 GSM
5.4.2 GPS
5.4.3 INMARSAT
5.4.4 LEO
5.4.5 MEO
5.4.6 Satellite Navigational System
5.4.6.1 GPS Position Location Principles
5.4.6.2 Differential GPS
5.5 Direct Broadcast satellites (DBS)
5.6 Direct to home Broadcast (DTH)
5.1 INTELSAT Series, INSAT
1. Explain the types of INTELSAT satellites with respect to basic spacecraft
characteristics and vehicle type. (April 2014)
2. Write about INTELSAT, INSAT and INMARSAT. (Nov/Dec 2012) [Apr/May 2023]
INTELSAT Series
INTELSAT - International Telecommunications Satellite
1
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
,EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• The formation of the international cooperative organization INTELSAT in 1964 paved the
way for the sophistication of satellite systems available today.
• There are other international organizations but none has stood the test of time as well as the
very successful INTELSAT systems, which provide voice, data, and video services.
• INTELSAT covers three main regions- AOR (Atlantic Ocean Region), IOR(Indian Ocean
Region) and POR (Pacific Ocean Region).
INTELSAT I:
• Known as Early Bird, this was launched in 1965 and was the first commercial
communications satellite operating over the Atlantic Ocean.
• It was a cylindrical, spin-stabilized satellite and had two transponders, each with about 30
MHz of bandwidth. The RF transmit power was about 4 W, and the EIRP was 12 to 14
dBW, indicating the antenna was an omni directional type.
• The equivalent isotropic radiated power (EIRP) is the product of power and gain.
• About 600 solar cells provided 45 W of power for all the circuitry.
• It had a capacity of either 240 voice telephone circuits, or one good-quality television
transmission.
• Its designed lifetime is extended to more than three years.
INTELSAT II:
• In 1967, three INTELSAT II satellites were put into operation.
• The first was placed over the Pacific Ocean to extend coverage to the Pacific region.
• The second was placed over the Atlantic Ocean to increase capacity for the Atlantic region,
and the third was also placed over the Pacific Ocean and acted as a spare.
• INTELSAT II was very similar to Early Bird in construction, but with improved channel
capacity.
2
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
,EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• With satellites over the Atlantic and Pacific, two thirds of the world’s area was covered by
communication satellites.
• INTELSAT II was designed to have a lifetime of three years.
INTELSAT III:
• During 1969, three INTELSAT III satellites were launched over the Atlantic, Pacific, and
Indian Oceans.
• This configuration saw the first global satellite coverage as initially proposed by Arthur
Clarke in 1945.
Figure: Coverage of INTELSAT
•
INTELSAT III introduced some new features, such as the despun antenna.
•
INTELSAT III was also the first in the series to use a highly directional antenna.
•
It had a beam width of 19°, which is just 2° more than the 17° requirement for global
coverage.
• The 2° margin was to allow for pointing error.
• The global antenna had a conical shape with a flare angle of 6°, and pointing accuracy was
maintained by controlling the despun motors with infrared sensors that detected the earth’s
horizon.
INTELSAT IV:
• During the period from 1971 to 1975, eight INTELSAT IV satellites were launched, of
which seven reached orbit and provided service.
• Increasing the INTELSAT IV capacity to 4000 telephony channels plus two TV channels
without increasing the bandwidth required some additional frequency reuse ingenuity.
• INTELSAT IV satellites each had twelve transponders of 36-MHz bandwidth, with a 4-
MHz guard band between adjacent transponders.
• The satellites had global coverage antennas and two 4.5° beamwidth spot beam antennas
that were steerable from earth.
3
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
, EC8094 SATELLITE COMMUNICATION UNIT V SATELLITE APPLICATIONS
• One of the two spot beams was directed to the east and the other to the west of an ocean
region.
• The objective of the spot beam transmissions was to provide more capacity for the heavier
traffic-generating routes, the spot beam capacity being approximately double the global
beam capacity.
• The shape of the beam could be modified by selecting the appropriate horns for
transmission.
• SCPC systems were first introduced on INTELSAT IV-A to provide more flexibility,
especially for low-traffic (thin) routes.
INTELSAT V:
• New technology employed on INTELSAT V included the use of the 14/11-GHz band.
• Linear polarization was used in this band because it provides better cross-polarization
discrimination at this frequency than does circular polarization.
• It also used three-axis body stabilization for the first time, instead of spin stabilization.
• The solar arrays producing 1228 W (after 10 years in orbit) were on flat panels instead of
around the cylindrical body, and a momentum wheel within the body of the satellite
provided gyroscopic stabilization.
• TDMA was first introduced for use with INTELSAT V.
• INTELSAT V-A uses the spatial and polarization frequency reuse techniques to enhance
bandwidth utilization.
INTELSAT VI:
• Satellite-switched TDMA was introduced for the first time with INTELSAT VI.
• The total available transponder bandwidth is 3330 MHz by using C- and Ku-bands,
orthogonal polarization, and spatial isolation.
• The 6/4-GHz frequencies are reused six times, and the 14/11-GHz frequencies are reused
twice.
• DCME started to have widespread use for more cost-effective voice traffic.
INTELSAT VII:
• The INTELSAT VII/VII-A series of satellites is a high-capacity and versatile fleet of
spacecraft deployed for global service.
• The INTELSAT VII design has 26 C-band and 10 Ku-band transponders that allow 18,000
telephone calls and three color TV broadcasts simultaneously, or up to 90,000 telephone
circuits using DCME.
• INTELSAT VII-A has 26 C-band and 14 Ku-band transponders, providing 22,500
telephone calls and three color TV broadcasts simultaneously, or up to 112,500 telephone
circuits using DCME.
• VII-A also has independently steerable C-band spot beams for better traffic-handling
capability. This satellite upgrades the IDR BER performance from 10–7 to 10–10 under
clear sky conditions.
4
Compiled by: Mr. S.Parthiban, M.Tech., Asst. Prof., Dept. of ECE, VRSCET.
