Glossary of Terms and acronyms

E1:
Transmission technique, based on European standards, which multiplexes together thirty 64 KBit/s voice (or equivalent) channels into a 256 bit frame for transmission at 2.048 MBit/s. The term is used as a shorthand for transmission rates of 2 MBit/s.

Earth Station:
The term used to describe the combination or antenna, low-noise amplifier (LNA), down-converter, and receiver electronics used to receive a signal transmitted by a satellite. Earth Station antennas vary in size from 2 foot to 12 foot (60 centimetres to 3.7 meters) diameter size used for TV reception to as large as 100 feet (30 meters) in diameter sometimes used for international communications.

Edge of Coverage:
Limit of a satellite's defined service area. In many cases, the EOC is defined as being 3 dB down from the signal level at beam centre. However, reception may still be possible beyond the -3dB point if the receive antenna is larger than that defined for normal service.

EIRP:
Effective Isotropic Radiated Power - This term describes the strength of the signal leaving the satellite antenna or the transmitting earth station antenna, and is used in determining the C/N and S/N. The transmit power value in units of dBW is expressed by the product of the transponder output power and the gain of the satellite transmit antenna.

Elevation:
The upward tilt of a satellite antenna measured in degrees relative to the horizon required to aim the antenna at the communications satellite. When aimed at the horizon, the elevation angle is zero. If it were tilted to a point directly overhead, the satellite antenna would have an elevation of 90 degrees.

EOL:
End of Life of a satellite.