ComStream CM601, Installation And Operation Manual

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6 Glossary
open loop ComStream packet protocol mode in which communication is sent in one
direction only from the controller to the slave; in this mode, the slave does not
respond to the controller, nor does it send any type of messages informing the
controller of commands received, nonexecuted commands, or error conditions
open network
operations in which Intelsat or Eutelsat standards are followed
PLL
phase-locked loop oscillator
PN
pseudonoise
P.O.C.
point of contact
propagation delay
delay from the time a signal is sent until it is received; caused by distance to and
from the satellite
PSK phase shift keying – form of modulation used to impress information onto an RF
carrier for transmission from one location to another
QPSK
quadrature phase shift keying – Quaternary (or quadrature) phase shift keying in
which four discrete phases of the carrier are used. In QPSK modulation, four
phases of the RF carrier, each differing by 90 degrees from the next, are employed
to represent two consecutive bits of the data stream. Such a signal may be
practically produced by using two double-balanced mixers and summing their
outputs in quadrature. In QPSK modulation, two information bits are encoded at
one time.
query
read command status
RD
receive data
Reed-Solomon codec
block-oriented coding system that is applied on top of standard Viterbi coding to
correct the bulk of the data errors that are not corrected by the other coding
systems, significantly reducing the bit error rates; available as an option card
RF
radio frequency
RHCP
right-hand circular polarized
RMA
return material authorization
R/O
receive-only
RS
request-to-send
RT
receive timing