Glossary: T


Abbreviation of Transmission Control Protocol, and pronounced as separate letters. TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.


Acronym for Transmission Control Protocol/Internet Protocol, the suite of communications protocols used to connect hosts on the Internet. TCP/IP uses several protocols, the two main ones being TCP and IP. TCP/IP is built into the UNIX operating system and is used by the Internet, making it the de facto standard for transmitting data over networks. Even network operating systems that have their own protocols, such as Netware, also support TCP/IP.


Or Uplink Station. The dishes, receivers, transmitters and other equipment on the ground that is needed to send and receive satellite signals.


A text information service transmitted together with the TV signal.

Terrestrial transmission

The national free-to-air TV broadcast technology that uses earth-based transmitters. The current analogue system is due to be replaced by a digital terrestrial system by 2012.


A satellite transmitter/receiver that receives uplinked signals from a satellite earth station, changes their form, and then rebroadcasts the altered signal back to earth.

Transport stream

The bit stream formed prior to transmission of signals by combining the video, audio and data streams of one service. It consists of fixed length packets of 188 bytes of data.

Travelling-Wave-Tube Amplifier (TWTA)

The main transmitter (microwave repeaters) on a satellite used to amplify the signal before it is rebroadcasted back to earth. One of these is associated with each transponder and determines the available radio frequency communications power.

Twin LNB

A universal LNB with dual outputs (independent) to connect a satellite receiver to a television set and a satellite modem to a computer. This makes it possible to watch television and access the internet at the same time, provided internet access is available.