Very High Speed Digital Subscriber Linetransmits data in the 13 Mbps – 55 Mbps range over short distances, usually between 1000 and 4500 feet (300 – 1500 meters), of twisted pair copper wire. The shorter the distance, the faster the connection rate.
As the final length of cable into the home or office, VDSL connects to neighborhood Optical Network Units (ONUs), which connect to the central office’s main fiber network backbone. This architecture will allow VDSL users to access the maximum bandwidthavailable through normal phone lines.
VDSL is currently going through a standards issue, so it isn’t widely deployed yet. The VDSL alliance favors a line coding scheme based on Discrete Multitone (DMT), a multi-carrier system that is more compatible with existing ADSLtechnology. The VDSL coalition favors a line coding scheme based on Quadature Amplitude Modulation (QAM), a single-carrier system that is less expensive and consumes less power.
- VDT radiation
The radiation emitted by video display terminals. Like televisions, computer monitors emit various types of radiation. Since the late 1980s, there has been a public debate about whether this radiation poses a health problem. To date, however, there is no conclusive evidence to settle the question once and for all.
Short for visual display unit, the old term for display monitors. The older VDUs included a CRT, a serial port to connect to a main computer, and a keyboard.
Short for Common Language Runtime, a runtime environment that manages the execution of .NET program code and provides services such as memory and exception management, debugging and profiling, and security. The CLR is a major component of the .NET framework. CLR also is known as the Virtual Execution System (VES).
Short for Video Electronics Standards Association, a consortium of video adapter and monitor manufacturers whose goal is to standardize video protocols.
Short for Virtual File Allocation Table, a virtual installable files system driver used in Windows for Workgroups and Windows 95. VFAT operates in protected mode and serves as an interface between applications and the File Allocation Table (FAT).