Microwave Radio Communications SCM4000, Техническое справочное руководство, Страница: 244 / 274

Glossary A-2 SCM4000 Operator’s Guide/Tech Ref Manual
ASI Asynchronous Serial Interface
A serial communications interface operating at
270 Mbit/sec., generally used in field news-gathering
operations.
ASYNC Asynchronous
Digital communication in which there is no timing
requirement for transmission and in which the start of
each character is individually signaled by the
transmitting device.
Baseband A composite signal in which video and audio signals
are combined together, with video occupying
approximately 0-4.5 MHz and audio modulated onto
subcarriers in the 5-6 MHz range. Also called
Composite.
BB Baseband
BDC Block Down Converter
BER Bit Error Ratio
The ratio of bits containing errors to the total number
of bits in the signal, over a time period.
BiasT A type of interconnection between the IDU and the
ODU. In Bias T wiring, IF and DC are combined and
carried on the coax cable up the ODU; blocking
circuitry prevents the DC from entering the IDU.
Table A-1: Useful Terms (Continued)
BISS Basic Interoperable Scrambling System
A means of encrypting and decrypting a digital signal
to prevent unauthorized reception. The encryption
and decryption are controlled by a digital key, which
is shared at both the transmitting and receiving
location.
BISS-1 BISS encryption that uses a fixed key.
BISS-E BISS encryption that uses an encrypted key.
BNC Bayonet lock coaxial connector
BPF Band Pass Filter
bps or b/sec Bits per second
BPSK Binary Phase Shift Keying
BW Bandwidth
CCITT International Telegraph and Telephone Consultative
Committee
A telecommunications standardizing committee of
the ITU.
CCPS Command & Control Power Supply
CENELEC European Committee for Electrotechnical
Standardization
CNR Carrier-to-Noise Ratio
COFDM Coded Orthogonal Frequency Division Multiplexing
Composite
(Baseband) A band or grouping of frequencies and/or subcarriers,
including video, occupied by the signal in a radio
transmission system. Also called Baseband.
CR4 Code Runner 4
CSI Channel-State Information
Table A-1: Useful Terms (Continued)