Satellite TV
Satellite TV is a broadcasting service which allows subscribers to receive television signals through a dish-shaped receiver unit. These signals are originally uploaded to a communications satellite that is in a fixed orbit above the earth, and then electronically scrambled to prevent unauthorized downloading. Those who pay a subscription fee for satellite TV service are issued both the receiving dish and a
descrambler. The actual tuning information is fed into the
television through a cable, much like the earth-bound cable
television services in competition with satellite TV providers.
Satellite TV solves
many of the problems associated with earlier television
broadcasting methods. Television stations originally
broadcast their signals in two specific radio wave bands- VHF (very high frequency) and UHF
(ultra-high frequency). Aerial antennas placed on roofs or
attached to the television itself would receive as much of
these radio wave transmissions as possible, but the results could be barely watch able depending on the strength of the signal, the terrain between the station and the television set, and
the atmospheric conditions. Cable television systems could
provide a better television signal, but this involved
stringing miles of insulated wire and creating subscription services.
Satellite TV provides a strong digital signal to subscribers' television sets and is almost completely wireless. Earlier satellite TV systems
used very large dish receivers in order to focus the
distant signals onto a powered antenna. Since different
television channels were located on different communication satellites,
these dishes would have to physically turn to predetermined
points in the sky in order to receive the proper signals.
Because regulation of these early dishes was not uniform,
illegal electronic descramblers became a lucrative
underground market. Stiffer penalties for unauthorized
descramblers paved the way for legitimate satellite TV subscription services.
Modern satellite TV services have streamlined the process. A single communication satellite now
remains in a steady orbit above the Earth, allowing all
subscribers to mount a much smaller dish receiver at a fixed
point. Technicians from the satellite TV provider may install the dish or owners can determine the proper receiving angle and do it themselves. Instead of scanning various satellites for different channels, modern satellite television
providers license the use of popular cable or broadcast
channels. Much like a cable system, the tuner descrambles
selected programs sent out on a specific frequency. This
allows satellite providers the option of pay-per-view movie rentals or the blocking of adult-oriented or premium movie channels.
Satellite TV services are especially popular in rural areas with poor broadcast reception and/or no cable service. Purchase of a receiving dish is generally limited to homeowners, not renters. Satellite dishes must have a clear line of sight to the satellite
itself for best reception. Some homeowners discover that a
grove of trees or mountainous terrain can be problematic.
Critics of satellite TV also mention reception problems during heavy rains or snowfall. Signals between an earth-bound receiver and a space-based satellite
can be affected by atmospheric conditions between them, but
other television services also have similar drawbacks. Many
customers prefer the additional channels available on satellite TV systems and the clarity of the digital signals.
No comments:
Post a Comment