Triple-Play Service Deployment

Glossary
Transport Stream A stream of 188-byte transport packets that contains audio, video, and data
belonging to one or several programs.
Tx Transmitter
Uplink Communication link from earth to a satellite
Upstream Rate The line rate for message or data transfer from the source machine to a destination
machine on the network.
US Upstream
UTC Universal Time Co-ordinated
VC Virtual Channel
VCI Virtual channel identifier. A unique numerical tag as defined by a 16 bit field in the
ATM cell header that identifies a virtual channel, over which the cell is to travel.
VCT Virtual Channel Table. ATSC table that describes a set of one or more channels or
services.Information in the table includes major and minor numbers, short channel
name, and information for navigation and tuning. There are two types of VCTs, the
TVCT for terrestrial systems and the CVCT for cable systems.
VDSL Very High Speed Digital Subscriber Line. Enhancement to DSL that permits
VFL
transmission of data up to 200mb/sec or more on a twisted copper pair utilizing a
bandwidth or frequency rage up to 30MH z.
Visual Fault Locator. The visual fault locator is a visual light source used to locate
breaks or point of excess loss in fiber cable.The common wavelengths are 635 nm,
650 nm and 670 nm.
VLC Variable Length Coding.This refers to a data compression method (Huffmann).
VoD Video on Demand, also VOD
VoIP Voice over Internet Protocol
VPI Virtual Path Identifier. An eight bit field in the ATM cell header which indicates the
virtual path over which the cell should be routed.
VSB Vestigial Sideband Modulation. The terrestrial modulation method used in the
ATSC. It can have either 8 (8 VSB) or 16 (16 VSB) discrete amplitude levels.
WAN Wide Area Network. A data communications network that spans any distance and
is usually provided by a public carrier.
WDM Wavelength Division Multiplexer. Passive fiber optic component which combines
optical channels on different wavelengths.
ZAP Time Elapsed time from sending an IGMP Join message until receipt of the first video
packet of the target broadcast video program stream.
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