V
VariableFrame Structure: A flexible frame structure whose length can be alteredto accommodate asymmetry transmission throughputs in opposite directions.
VAX: Virtual Address eXtension. The most successfulminicomputer design in industry history, developed by DEC.
VBI: Vertical Blanking Interval
vBNS: very high-speed Backbone Network Service;participating sites include; San Diego Supercomputer Center, the NCSAin Illinois, Cornell Theory Center in New York, Pittsburgh SupercomputerCenter, and the National Center for Atmospheric Research in Colorado, (seehttp://www.vbns.net for more info.)
VCCO: Voltage Controlled Crystal Oscillator;A high-accuracy crystal oscillator whose frequency can be slightyly adjustedthrough applying different amounts of voltage.
VCI: Virtual Channel Identifier; a header fieldwithin an ATMcell, used to distinguish between multiple application streams in a given'Virtual Path'.
VCTV: Viewer Controlled Television
VDSL: Very high bit rate Digital SubscriberLine / Loop; Modem for twisted-pair access operating at data rates from12.9 to 52.8 Mbps with corresponding maximum reachranging from 4500 feet to 1000 feet of 24 gauge twisted pair.
VEMMI: Videotex Enhanced Man/Machine Interface
VESA: Video Electronics Standards Association
VFR: Variable Frame Rate; one of Frame Relay'sanswers to QoS. VFR comes in to modes "rt VFR"; real-timeand "nrt VFR"; non-real-time.
VHDL: Vhsic Hardware Description Language,(not Verilog's HDL). See IEEE Standard 1364 for those differences.
vi: [sic] Visual Interface; A screen editorcrufted together by Bill Joy for an early BSD release.vi became the de facto standard Unix editor and a nearly undisputed hackerfavourite outside of MIT until the rise of EMACSafter about 1984.
VIP: Video Information Providers
Virtual Circuit Identifier:At the UNI, the connection is identified by two valuesin the cell header: the virtual path identifier (VPI)and the virtual channel identifier (VCI). Both theseVPI and VCI combines together toform a virtual circuit identifier.
VITC: Vertical Interval TimeCode; Timecodeinformation in digital form, added into the vertical blanking of a TV signal.This can be read by the video heads from tape at any time pictures aredisplayed, even during jogging and freeze but not during spooling. Thiseffectively complements LTC ensuring timecode can beread at any time. See also: LTC
Viterbi Algorithm:A received data symbol recovery procedure whose decision maiking is basedon a sequence of received data symbols.
VLIW: Very Long Instruction Word
VLSI: Very Large Scale Integration; A high-densitysemiconductor circuit that can include multiple signal processing capabilitiesin a single chip.
VM: 1. Virtual Machine; mainframe operatingsystem, (IBM).2. Virtual Machine; has also been used as a generalized abstraction fora software application core or engine.
VM: Verification Model, (ISO/IEC)
VMS: ? ;mini to mainframe operating system,(DEC)
VON Coalition: Voice On the Net Coalition;formed to pursue the rights of netizen's to use voice over the Internet.
VP: Virtual Path; provides a path between twoor more hosts, upon which several 'VirtualChannels' can be multiplexed, allowing several application streamsto be routed through an ATMswitch simultaneously.
VRAM: Video Random Access Memory
VRML: Virtual Reality Modeling Language
VSB:Vestigial Sideband; a modulation technique refering to the characteristicsof the RF/Transmission subsystem of the Digital TelevisionStandard. The VSB system offers two modes: aterrestrial broadcastmode, (8-VSB) with 8 discrete amplitude levels supportinga payload data rate of 19.28 Mb/s in a 6 MHz channel, and a high data ratemode, (16-VSB) with 16 discrete amplitude levels supportinga payload of 38.57 Mb/s. The high data rate mode trades off transmissionrobustness for payload data rate.