Microwave Radio Communications SCM4000, Technical Reference Manual

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Glossary A-5 SCM4000 Operator’s Guide/Tech Ref Manual
LBO Line Build Out
LCD Liquid Crystal Display
Lcl Local
LED Light Emitting Diode
LIU Line Interface Unit
LNA Low Noise Amplifier
LNB Low Noise Block Down Converter
LNC Low Noise Converter
LO Local Oscillator
LOS Loss of Signal
LPF Low Pass Filter
LQ Link Quality
Mbps Megabits per second
MHz Million (1,000,000) cycles per second
MPEG Moving Picture Experts Group
M-QAM M-order of Quadrature Amplitude Modulation
MRC Microwave Radio Communications
Multipath An unpredictable set of reflections and/or direct
waves, each with its own degree of attenuation and
delay. Due to obstacles and reflectors in the wireless
channel, transmitted signals arrive at the received
from various directions over multiple paths.
MUX Multiplexer
NC Normally Closed (Relay or switch contacts)
N/C No Connection
NICAM Near-Instantaneous Companding and Multiplexing
NO Normally Open (Relay or switch contacts)
Table A-1: Useful Terms (Continued)
NRZ Non-Return-to-Zero (Modulation)
NTSC National Television System Committee
Color television standard used in the US. Provides
525 horizontal lines of resolution. Not compatible with
PAL or SECAM.
Null modem
cable An RS-232 cable designed to connect two computers
(or other data sources) together. It has male DB9
connectors on each end, to mate with the DB9
female connectors on the PCs. It also has the
Transmit and Receive connections crossed over so
Transmit (pin 3) on one end connects to Receive (pin
2) on the other.
Also called “Crossover Cable”.
ODU Outdoor Unit
OFDM Orthogonal Frequency Division Multiplexing
OOK On-Off Keying
PAL Phase Alteration Line
Color television standard used in many European
countries. Provides 625 horizontal lines of resolution.
Not compatible with NTSC or SECAM.
PAL-M Phase Alteration Line
Color television standard used in many European
countries. Provides 625 horizontal lines of resolution
with 50 lines per field. Not compatible with NTSC or
SECAM.
Table A-1: Useful Terms (Continued)