Harmonic NSG 9116 Hardware Installation page 79

Glossary
P
packet
A block of data used for transmission.
PID
packet identifier. Integer values used in the
MPEG-2 standard to identify an elementary
stream of a program within a transport
stream.
pinouts
The description and purpose of each pin in
a connector.
port
A port is an input to or an output from a
component, an adapter, or a module.
Q
QAM
quadrature amplitude modulation.
Transmits 4 bits (16 QAM) to 8 bits
(64 QAM) at the same time by varying the
phase and amplitude of a signal. QAM can
only be used on very quiet transmission
media, such as downstream-only coaxial
cable or fiber, because amplitude
modulation is susceptible to interfering
signals.
R
redundancy
A back-up system of Harmonic components
that ensures uninterruptable service in the
event of a component failure.
EIA
Electronic Industries Alliance. A U.S. trade
organization that is responsible for
establishing hardware interface standards.
EIA-232
An EIA standard interface for connecting
serial devices (DCEs), such as modems,
monitors, mice, and serial printers to a DTE.
EIA-232 supports the 25-pin D-type
connector (DB-25) and a 9-pin D-type
connector (DB-9).
S
SFP
small form factor pluggable transceiver.
singlemode fiber
Optical fiber designed for the transmission
of a single ray or mode of light as a carrier
and is used for long-distance signal
transmission. For short distances,
multimode fiber is used.
SNMP
Simple Network Management Protocol. The
protocol that Harmonic control and
management systems use to configure and
monitor Harmonic devices remotely over IP.
subscriber
The end user of a broadcast system; the
person who views programs for
entertainment purposes.
T
transport stream
One or more multiplexed MPEG-2
programs.
V
VAM
video access manager.
VAM 71