|
|
|
|||
|
|
|
|
||
|
|
|
Glossary
|
|
T
|
3G. 3G is an ITU specification for the third generation (analog cellular was the first generation, digital PCS the second) of mobile communications technology. 3G promises increased bandwidth, up to 384 Kbps when a device is stationery or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications. 3G will work over wireless air interfaces such as GSM, TDMA, and CDMA. The new EDGE (Enhanced Data rates for Global Evolution) air interface has been developed specifically to meet the bandwidth needs of 3G.
tag. The format code that defines portions of an HTML file or embedded applets, controls, or scripts.
tar. A contraction of tape-archiver, a backup and archiving program used on UNIX computers. In addition to copying files to a tape backup, tar can also be used to clump a bunch of files together, slapping the TAR extension on them.
TCP. Transmission Control Protocol (TCP). A connection-based protocol responsible for breaking data into packets which the IP protocol sends over the network. This protocol provides a reliable sequenced communication stream for internetwork communication.
TCP/IP. Acronym for Transmission Control Protocol/Internet Protocol. The suite of communications protocols the Internet uses to communicate. The primary wide area network used on the worldwide Internet. TCP/IP includes standards for how computers communicate and conventions for connecting networks and routing traffic, as well as specifications for utilities.
TDMA. Short for Time Division Multiple
Access, a technology for delivering digital wireless service
using time-division multiplexing (TDM). TDMA works by dividing a radio
frequency into time slots and then allocating slots to multiple calls.
In this way, a single frequency can support multiple, simultaneous data
channels. TDMA is used by the GSM digital cellular system.
telnet. The network protocol that provides virtual terminal service on TCP/IP networks.
terminal emulation. The ability of an average, run-of-the-mill desktop computer to cleverly disguise itself as a certain type of terminal hooked up to a mainframe computer. This can only be done with the right software called terminal emulation software.
The Open Group. An international consortium of computer and software manufacturers and users dedicated to advancing multi-vendor technologies. The Open Group was formed in February, 1996 by merging two previously independent groups - the Open Software Foundation (OSF) and X/Open Company Ltd. One of the most important technologies fostered by The Open Group is DCE.
three-dimensional spreadsheet. In spreadsheet technology, a group of spreadsheets organized like the pages of a book; in addition to the usual rows and columns, three-dimentional spreadsheets also have depth.
TIFF. Acronym for Tagged Image File Format. A bitmapped graphics file format used frequently for images read in using a scanner. TIFF files are high-resolution dot images.
token. A small data frame used in a token-passing network to indicate which computer is allowed to transmit data.
token passing. A media access method that eliminates collisions and ensures that every computer gets an equal opportunity to communicate on the network. The token is continually passed around the network, and each computer can only transmit a message when it has the token.
toggle. A type of switch that typically alternates between two modes, on or off.
Token ring. A network architecture, developed by IBM in the middle 1980s, that is physically wired using a star topology but is implemented as a logical ring. Token-Ring networks use token passing to ensure that each computer on the network gets a chance to transmit data.
topology. Topology refers to the configuration of a local area network -- how the network is physically laid out. The basic types are centralized and decentralized; the basic formats are the star topology (centralized) and the bus and ring topologies (decentralized).
trackball. An input device that operates very similary to a mouse. Where a mouse has a bell you roll on your table top, in the case of the track ball, the ball part is on top and you rotate it using your fingers.
Trojan Horses. A nasty computer program cleverly hidden inside a legitimate program. It comes from a strategy used in the Trojan War. Sneaky computer programs that pretend to one thing while disguising a more nefarious deed are called Trojan horses. You are more likely to find a Trojan horse packaged inside shareware or forewarn than in off-the-shelf commercial software.
tweak. To customize, tailor, adjust, rearrange, cajole, or otherwise mess with. More specifically, it means changing settings on a piece of hardware or software so that your needs are more closely attended to.
twisted pair. A wire that is a pair of wires wrapped around each other. It is the kind of wire typically used in commercial telephone systems. It is also used in local area networks, especially those that use common phone wiring to connect the computers. The good thing about twisted pair is that it's cheap and ubiquitous; the drawback is that it doesn't carry nearly as much information as the thicker coaxial cable.
Back to Top Next-->
