UNIT V SATELLITE APPLICATIONS
5.1 INTELSAT Series:
INTELSAT stands for International Telecommunications Satellite. The
organization was created in 1964 and currently has over 140 member countries and
more than 40 investing entities (see http://www.intelsat.com/ for more details).
In July 2001 INTELSAT became a private company and in May 2002 the
company began providing end-to-end solutions through a network of teleports,
leased fiber, and points of presence (PoPs) around the globe.
Starting with the Early Bird satellite in 1965, a succes- sion of satellites has
been launched at intervals of a few years. Figure 1.1 illustrates the evolution of
some of the INTELSAT satellites. As the figure shows, the capacity, in terms of
number of voice channels, increased dramatically with each succeeding launch,
as well as the design lifetime.
These satellites are in geostationary orbit, meaning that they appear to be
stationary in relation to the earth. At this point it may be noted that geosta-
tionary satellites orbit in the earth’s equatorial plane and their position is specified
by their longitude.
For international traffic, INTELSAT covers three main regions—the
Atlantic Ocean Region (AOR), the Indian Ocean Region (IOR), and the Pacific
Ocean Region (POR) and what is termed Intelsat America’s Region.
For the ocean regions the satellites are positioned in geostationary orbit
above the particular ocean, where they provide a transoceanic telecommunications
route. For example, INTELSAT satellite 905 is positioned at 335.5° east longitude.
The INTELSAT VII-VII/A series was launched over a period from October
1993 to June 1996. The construction is similar to that for the V and VA/VB series,
shown in Fig. in that the VII series has solar sails rather than a cylindrical body.
The VII series was planned for service in the POR and also for some of the
less demanding services in the AOR. The antenna beam coverage is appropriate
for that of the POR. Figure 1.3 shows the antenna beam footprints for the C-band
hemispheric cover- age and zone coverage, as well as the spot beam coverage
possible with the Ku-band antennas (Lilly, 1990; Sachdev et al., 1990). When used
,in the AOR, the VII series satellite is inverted north for south (Lilly, 1990), minor
adjustments then being needed only to optimize the antenna pat- terns for this
region. The lifetime of these satellites ranges from 10 to 15 years depending on
the launch vehicle.
Recent figures from the INTELSAT Web site give the capacity for the
INTELSAT VII as 18,000 two-way telephone circuits and three TV channels; up to
90,000 two-way telephone circuits can be achieved with the use of “digital circuit
mul- tiplication.”
The INTELSAT VII/A has a capacity of 22,500 two-way telephone circuits
and three TV channels; up to 112,500 two-way tele- phone circuits can be achieved
with the use of digital circuit multipli- cation. As of May 1999, four satellites were
in service over the AOR, one in the IOR, and two in the POR.
Figure 5.1 INTELSAT Series
, The INTELSAT VIII-VII/A series of satellites was launched over the
period February 1997 to June 1998. Satellites in this series have similar capacity
as the VII/A series, and the lifetime is 14 to 17 years.
It is standard practice to have a spare satellite in orbit on high-
reliability routes (which can carry preemptible traffic) and to have a ground spare
in case of launch failure.
Thus the cost for large international schemes can be high; for example,
series IX, described later, represents a total investment of approximately $1
billion.
Figure 5.2 Region of glob
5.2 INSAT:
INSAT or the Indian National Satellite System is a series of
multipurpose geo-stationary satellites launched by ISRO to satisfy the
telecommunications, broadcasting, meteorology, and search and rescue
operations.
Commissioned in 1983, INSAT is the largest domestic communication
system in the Asia Pacific Region. It is a joint venture of the Department of
Space, Department of Telecommunications, India Meteorological Department,
5.1 INTELSAT Series:
INTELSAT stands for International Telecommunications Satellite. The
organization was created in 1964 and currently has over 140 member countries and
more than 40 investing entities (see http://www.intelsat.com/ for more details).
In July 2001 INTELSAT became a private company and in May 2002 the
company began providing end-to-end solutions through a network of teleports,
leased fiber, and points of presence (PoPs) around the globe.
Starting with the Early Bird satellite in 1965, a succes- sion of satellites has
been launched at intervals of a few years. Figure 1.1 illustrates the evolution of
some of the INTELSAT satellites. As the figure shows, the capacity, in terms of
number of voice channels, increased dramatically with each succeeding launch,
as well as the design lifetime.
These satellites are in geostationary orbit, meaning that they appear to be
stationary in relation to the earth. At this point it may be noted that geosta-
tionary satellites orbit in the earth’s equatorial plane and their position is specified
by their longitude.
For international traffic, INTELSAT covers three main regions—the
Atlantic Ocean Region (AOR), the Indian Ocean Region (IOR), and the Pacific
Ocean Region (POR) and what is termed Intelsat America’s Region.
For the ocean regions the satellites are positioned in geostationary orbit
above the particular ocean, where they provide a transoceanic telecommunications
route. For example, INTELSAT satellite 905 is positioned at 335.5° east longitude.
The INTELSAT VII-VII/A series was launched over a period from October
1993 to June 1996. The construction is similar to that for the V and VA/VB series,
shown in Fig. in that the VII series has solar sails rather than a cylindrical body.
The VII series was planned for service in the POR and also for some of the
less demanding services in the AOR. The antenna beam coverage is appropriate
for that of the POR. Figure 1.3 shows the antenna beam footprints for the C-band
hemispheric cover- age and zone coverage, as well as the spot beam coverage
possible with the Ku-band antennas (Lilly, 1990; Sachdev et al., 1990). When used
,in the AOR, the VII series satellite is inverted north for south (Lilly, 1990), minor
adjustments then being needed only to optimize the antenna pat- terns for this
region. The lifetime of these satellites ranges from 10 to 15 years depending on
the launch vehicle.
Recent figures from the INTELSAT Web site give the capacity for the
INTELSAT VII as 18,000 two-way telephone circuits and three TV channels; up to
90,000 two-way telephone circuits can be achieved with the use of “digital circuit
mul- tiplication.”
The INTELSAT VII/A has a capacity of 22,500 two-way telephone circuits
and three TV channels; up to 112,500 two-way tele- phone circuits can be achieved
with the use of digital circuit multipli- cation. As of May 1999, four satellites were
in service over the AOR, one in the IOR, and two in the POR.
Figure 5.1 INTELSAT Series
, The INTELSAT VIII-VII/A series of satellites was launched over the
period February 1997 to June 1998. Satellites in this series have similar capacity
as the VII/A series, and the lifetime is 14 to 17 years.
It is standard practice to have a spare satellite in orbit on high-
reliability routes (which can carry preemptible traffic) and to have a ground spare
in case of launch failure.
Thus the cost for large international schemes can be high; for example,
series IX, described later, represents a total investment of approximately $1
billion.
Figure 5.2 Region of glob
5.2 INSAT:
INSAT or the Indian National Satellite System is a series of
multipurpose geo-stationary satellites launched by ISRO to satisfy the
telecommunications, broadcasting, meteorology, and search and rescue
operations.
Commissioned in 1983, INSAT is the largest domestic communication
system in the Asia Pacific Region. It is a joint venture of the Department of
Space, Department of Telecommunications, India Meteorological Department,
