ND SatCom SKYWAN IDU 7000, Manual

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2010-10-26 Network Design and Engineering Guide 141
Appendix C - Glossary
8 APPENDIX C - GLOSSARY
Term Definition
Antenna For satellite communication over geosynchronous satellites
parabolic reflector antennas are used.
Backup Master A slave station that is ready in terms of hardware, software and
configuration to take over the role of a master station. See also
Master Station.
Bandwidth A range of frequencies within a spectrum, expressed in Hertz.
Also used for the data transfer rate or throughput, expressed
in bits per second.
Beam Radio transmission focused into a certain direction in order to
achieve a high power density in that direction.
Bit Rate Speed of transmission, measured in bits per second (bps).
Binary Phase Key Shifting
(BPSK) Modulation scheme that uses two phases separated by 180
degrees.
Block Up Converter (BUC) Used for transmission towards the satellite (uplink); converts
from a lower frequency to a higher frequency using a fixed os-
cillator frequency.
Burst A short transmission over the satellite link. The burst time is
smaller than the time slot.
Carrier to Noise Ratio
(C/N) The ratio of the received carrier power and the noise power in
a given bandwidth expressed in dB. The higher the C/N the
better the quality.
C band Frequency band with uplink 5.925 to 6.425 GHz, downlink 3.7
to 4.2 GHz.
Container Part of a data burst reserved for user traffic.
Coverage Footprint or the area on the earth's surface that is covered by
a satellite's transmission beam.
Cross Strapped Trans-
ponder A bent pipe transponder with uplink and downlink coverage lo-
cated in different areas, e.g. uplink in Europe, downlink in USA.
See also Transponder.
Datagram Unit of transmission in the network layer (such as IP). A data-
gram may be encapsulated in one or more packets passed to
the data link layer.
dBW The ratio of the power to one Watt expressed in decibels. Typ-
ically the EIRP of satellite beams are measured in dBW.
Double Hop Transmission of information from one terminal to another ter-
minal in two stages via an intermediate hub station. Typical for
star networks.