Page 29 - Satellite Communications, Fourth Edition

Overview of Satellite Systems 9

TABLE 1.3 INTELSAT Geostationary Satellites
Satellite Location Number of transponders Launch date
901 342°E Up to 72 @ 36 MHz in C-Band June 2001
Up to 27 @ 36 MHz in Ku Band
902 62°E Up to 72 @ 36 MHz in C-Band August 2001
Up to 23 @ 36 MHz in Ku Band
903 325.5°E Up to 72 @ 36 MHz in C-Band March 2002
Up to 22 @ 36 MHz in Ku Band
904 60°E Up to 72 @ 36 MHz in C-Band February 2002
Up to 22 @ 36 MHz in Ku Band
905 335.5°E Up to 72 @ 36 MHz in C-Band June 2002
Up to 22 @ 36 MHz in Ku Band
906 64°E Up to 72 @ 36 MHz in C-Band September 2002
Up to 22 @ 36 MHz in Ku Band
907 332.5°E Up to 72 @ 36 MHz in C-Band February 2003
Up to 23 @ 36 MHz in Ku Band
10-02 359°E Up to 70 @ 36 MHz in C-Band June 2004
Up to 36 @ 36 MHz in Ku Band

described in detail in later chapters, but for comparison purposes it
may be noted that one 36 MHz transponder is capable of carrying about
9000 voice channels, or two analog TV channels, or about eight digital
TV channels.
In addition to providing transoceanic routes, the INTELSAT satellites
are also used for domestic services within any given country and regional
services between countries. Two such services are Vista for telephone and
Intelnet for data exchange. Figure 1.4 shows typical Vista applications.

1.4 U.S. Domsats
Domsat is an abbreviation for domestic satellite. Domestic satellites are
used to provide various telecommunications services, such as voice,
data, and video transmissions, within a country. In the United States,
all domsats are situated in geostationary orbit. As is well known, they
make available a wide selection of TV channels for the home enter-
tainment market, in addition to carrying a large amount of commercial
telecommunications traffic.
U.S. Domsats, which provide a DTH television service, can be classi-
fied broadly as high power, medium power, and low power (Reinhart,
1990). The defining characteristics of these categories are shown in
Table 1.4.
The main distinguishing feature of these categories is the equivalent
isotropic radiated power (EIRP). This is explained in more detail in
Chap. 12, but for present purposes it should be noted that the upper limit