Comtech EF Data Vipersat SLM-5650A User Manual page 140

BPM
Bridge Point-to-Multipoint – Routing mode option available in the SLM-5650A
satellite modem.
BPSK Binary Phase Shift Keying – Sometimes referred to as 2-PSK. A digital modu-
lation technique in which the carrier is phase shifted +/-180 degrees (two
phases). The simplest and most robust of all PSKs, but unsuitable for high data-
rate applications when bandwidth is limited due to encoding just one bit per
symbol. See also QPSK and OQPSK.
BUC Block Up Converter – An upconverter so called because it converts a whole
band or "block" of frequencies to a higher band. The IF is converted to final
transmit frequency for satellite communications. The BUC is part of the satellite
ODU/transceiver.
C-band A frequency band commonly used for satellite communications (and sometimes
terrestrial microwave). For terrestrial earth stations, the receive frequency band
is 3.7–4.2 GHz and the transmit frequency band is 5.925–6.425 GHz. See also
Ku-band and L-band.
CDD Comtech Data Demodulator
CDM
Comtech Data Modem
CIR Committed Information Rate – The guaranteed minimum bandwidth assigned
to a remote terminal.
CLI Character Line Interface – A mechanism for interacting with a computer oper-
ating system or software by typing commands to perform specific tasks.
Codecast
A network coding based ad hoc multicast protocol well-suited for multimedia
applications with low-loss, low-latency constraints. Because data is streamed
with no verification, high delivery ratios are obtained with very low overhead.
CRC
Cyclic Redundancy Check – A method of applying a checksum to a block of
data to determine if any errors occurred during transmission over communica-
tions links.
CXR
Carrier – A radio frequency transmission linking points and over which infor-
mation may be carried.
D-2
C
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