Down to Earth Solutions |
would like to thank BroadcastingLinks.com
for giving permission to reprint this article
authored by their editor Doug Jessop
Here is a basic glossary of terms used in the satellite industry:
AOR- Atlantic Ocean Region. Designation for international satellites that are located over the Atlantic Ocean. This term is used extensively in international video traffic, especially to Europe.
C-Band, Ku-Band,Hybrid satellites- The type of satellite based on the frequency that the signals operate. C-Band satellites operate at a lower frequency than Ku-Band satellites. Ku-Band also has a smaller bandwidth (about the size of a raindrop) which allow for receive dishes to be smaller then C-Band. Because of the size of the Ku-bandwidth, feeds may experience rain fade with severe storms. Hybrid satellites have both C-Band and Ku-Band capabilities on the same satellite.
Channel- The numerical dial position that a transponder is found on a IRD. The channel number is not always the same as the transponder number. On a number of older satellites, the numbering alternates between Vertical and Horizontal...transponder 1V is channel 1, transponder 1H is channel 2 transponder 2V is channel 3, etc.
Cross-strapping- A technology on the new generation satellites that enables a feed to be transmitted in C-Band and received in Ku-Band and vica versa. Also known as a "turnaround in the air."
D/L or U/L Frequency Downlink or Uplink Frequency. This is in essence the street address that you punch into your equipment to either uplink or downlink to a particular transponder.
EIRP- Estimated Isotropic Radiated Power. A fancy way of saying what the footprint, or geographic coverage of the satellite is.
Encryption- Also known as scrambling. A system that takes the signal and reconfigures it into something that is unusable without a corresponding decoder. Examples of encryption systems include SA B-MAC, GI Videocipher and LEITCH.
EOL- End of Life. The EOL is based on how much fuel is on board the satellite to keep it in its geosynchronous orbit 22,300 miles above the Equator. Videoconferencing managers planning a future broadcast should take note of EOL dates. Satellites generally have a projected lifetime of about 10 years. New generation satellites being launched this year have estimated lifetimes of 12-15 years.
EST- Eastern Standard Time. EST is used frequently to refer to broadcast times which are going to take place only in the domestic U.S.A.
GMT- Greenwich Mean Time. The international time standard, originating from Greenwich, England. While U.S. broadcasts are based on Eastern time, all international video transmissions are based on Greenwich Mean Time .
HPA- High Powered Amplifier. The piece of equipment (also known as transmitter) at the uplink that boosts the signal to the satellite at 186,000 miles per second (the speed of light).
IFB- Interrupted Feedback. Here is a fun one, IFB is the earpiece they put in the talents ear so the director can talk to him/her without being heard by the guest or the viewers.
INTELSAT - The international consortium that includes all the countries that own and operate a particular international satellite.
IOR- Indian Ocean Region. Designation for international satellites that are located over the Indian Ocean. This term is used extensively in international video traffic, especially to the Middle East.
IRD-Integrated Receiver/Decoder. The receiver that converts the downlink signal into something that your TV monitor understands as a picture. The IRD also takes encrypted signals and decodes it into usable video.
LNB- Low Noise Block Converter. The equipment in a downlink that takes the high frequency signal from the satellite and converts it to a lower frequency signal that can be fed through cable to your receiver.
Polarity-The way that the signal is propagated to space, in either a Vertical or Horizontal plane. For example, terrestrial TV signals are received by a horizontal antenna, the antenna for your car radio is vertical. Satellite dishes can send and receive in either polarity, depending on which way the feedhorn is rotated.
POR- Pacific Ocean Region. Designation for international satellites that are located over the Pacific Ocean. This term is used extensively in international video traffic, especially to Asia and Australia.
Transponder- The designation that the carrier gives to the isolated frequency on a satellite. Depending on the satellite, most satellites have 24 transponders or channels.
TWTA power- Traveling Wave Tube Amplifier power. The power at which the signal is delivered from the satellite. Video network managers with sites at the fringe areas of the footprint of a satellite should look at TWTA power for possible weak signals.
TVRO- Television Receive Only. A satellite dish that serves as a downlink only.
U.S. DOMSAT- U.S. Domestic Satellite. Satellites that serve the U.S.
Without sounding too trite, the day that anyone stops learning is the day they stop living. With the fast pace of our industry you can't afford to hold the belief that you know everything. This holds true for the newcomer as much as for the veteran. This article was written with the intent to help demystify our industry and make it more accessible to people that don't hold an advanced degree in engineering. While this article does not profess to be a technical dissertation, hopefully some light has been shed on what can be a very rewarding, albeit sometimes confusing profession.
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