Page 74 - Communications Satellites Global Change Agents

50 IPPOLITO AND PELTON

Eutelsat and others following in 2003. Several other Ka-band systems are in var-
ious stages of development and will be deployed over the next few years. A ma-
jor FSS move to Ka-band, which was anticipated with much excitement in the
mid- to late 1990s, has been deferred or slowed because of technical and cost
challenges as well as limited market demand. These problems are still to be fully
overcome. Briefly, the challenges currently being faced with regard to the use of
the Ka-band frequencies and higher include the following:

• Rain Attenuation or Rain Fade: The higher the satellite operating frequency,
the greater the problem with so-called rain attenuation. In simple terms, the closer
the wavelength used for satellite communications approximates the size of rain
drops, the greater is a tendency for the rain to act as a lens that distorts or bends the
radio signal and weakens the signal at the receive site. During heavy rainfall, this
can even cause the receive antenna to lose the signal. To combat this problem,
high power, improved signal processing, and other digital processing techniques
must be used to make Ka-band service reliable. The Astra Ka-band system in Eu-
rope has the advantage of the best climatic conditions in the world for this service.
• Satellite and Terminal Cost and New Technology Development: The devel-
opment of these new technologies involves a good deal of research and develop-
ment (R&D) expense to develop both the satellites and new ground antenna sys-
tems. The ability to design components that can reliably operate at such high
frequencies and extremely small wavelengths is a major technical challenge.
Thus, the earliest systems, both satellites and ground systems, tended to cost more
money. Some electronic components that are designed to operate at these ex-
tremely demanding frequencies are difficult to design, build, and operate reliably.
For the most part, radio tube technology is still required to deliver high-power
performance at these extremely high frequencies. Q/V-band systems (i.e., 48 GHz
and 38 GHz) have been filed with the ITU and with the FCC in the United States.
However, none of these satellites is yet in the construction phase, and deployment
will most likely be deferred until well after the Ka-band has been utilized and
tested. In short, operational satellites in the Q/V bands are at least a decade or
more away. The newly adopted FCC licensing provisions (mid-2003) that require
the posting of bonds and milestones that must be met to have multimillion dollar
bonds returned to filing organizations will likely serve to slow the use of these
new satellite bands even further.

THE DEVELOPMENT OF FSS SYSTEMS

The FSS category consists of four general classes of systems based on the service
area provided: domestic, international, regional, and global.