User’s Guide 6-3
LNB (Low Noise Block
converter)
See Converter.
Local oscillator Converter component which shifts the converter received frequency (10750-11700 MHz
for low band; 11,700- to 12,750 MHz for high band) to the intermediate frequency
receivable by the digital receiver tuner.
LNB switch frequency Used with multiple oscillators. The frequency demarcating the end of the low band and
the start of the high band; the set point in received frequency that triggers a switch from
one oscillator to another. The value is usually 11,700 MHz for most LNBs. Not to be
confused with the “22 kHz tone,”which is a control signal for the LNB.
MAC Media Access Control. A “MAC address” is a device’s unique hardware number, as
recognized by other devices on the network. In a system that uses a MAC addressing
scheme, DVB MPEG Transport Stream data intended for a particular device must
include that device’s MAC address.
Modulation The process by which electromagnetic radiation is modified to represent digital or ana-
log information for transfer across distances. In modulation, electromagnetic waves are
typically altered in phase or other characteristics.
MPEG-2 Digital data compression format which uses powerful algorithms to greatly reduce the
size of final data. Developed by an international research group (the Motion Picture
Expert Group - MPEG), it is the system used to compress the digital data for the DVB
signals.
MPEG-2 transport stream See DVB MPEG Transport Stream.
Multicast Communication between a single sender and multiple receivers on a network. The mul-
ticast sent from the Internet to a network travels most of the distance as a single stream,
which splits at the last instant to reach multiple users.
The provider allocates one or more specific PID numbers for multicast data, which the
digital receiver must be configured to recognize.
Multi-feed Two or more converters positioned on the same fixed antenna dish to get signals from
two or more satellites whose orbital positions are sufficiently close to each other.
NIT Network Information Table. A packet included in the DVB MPEG Transport Stream
that lets the recipient know what additional network information it must retrieve to make
up a network resource.
Packet A unit of data of a fixed size and composition, formatted for transport; often refers to a
MPEG DVB Transport Stream packet.
Oscillator See Local Oscillator.
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