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48 IPPOLITO AND PELTON
FIG. 2.6. Comparison of different size, scale, and types of satellites—"three-axis
body stabilized" spacecraft.
THE ROLE OF THE ITU IN THE REGULATION
OF SATELLITE SYSTEMS
When the first communications satellites began operations, there was only one
type defined by the International Telecommunication Union (ITU), and this was
known as fixed satellite services (FSS). The Geneva-based ITU is the specialized
international agency within the UN structure that provides regulatory oversight,
recommended performance standards, and frequency allocations for worldwide
telecommunications, including satellite systems. The definition of FSS included
telephone, telegraph, data, radio, and TV services—when provided between the
large fixed satellite ground stations. Today, the number of satellite services allo-
cated frequency by the ITU has expanded to a sizable number and now number al-
most 20.
International frequency allocations are now specified by the "radio wave sec-
tion" of the International Telecommunication Union (the ITU-R), and these allo-
cations are based on the type of service provided by the telecommunications sys-
tem. The allocations include those needed for terrestrial, mobile, satellite, and
