Glossary: I


Interactive low noise block

An interactive dish.

Interactive Services

Supplementary services offered to television viewers. Usually, the digibox is connected to the telephone network via an integral modem, and the viewer can use the remote control to order films and football matches directly. In some countries viewers can vote in television programmes and order meals for home delivery. The programme provider can charge for these services.

Interactive TV

TV programming where consumers can initiate, respond to, or participate in what is happening on screen.

IP addresses

An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods.

IP (internet protocol) multicasting

Sending data to distributed servers on a multicast backbone. For large amounts of data, this is more efficient than standard internet traffic because a message can be broadcast to many recipients simultaneously. Traditional internet traffic requires separate connections for each source-destination pair. IP multicasting allows many recipients to share the same source so that just one set of information is transmitted for all destinations.


IP television uses the internet as the delivery infrastructure for TV programmes and stations.


Integrated receiver decoder

A set-top box used for the reception and decoding of broadcast signals.


ITU is the United Nation's specialised agency for telecommunications. The ITU holds periodic conferences at which telecommunications issues of global importance re discussed; the main conferences are the World Radio Conference (WRC) and the World Telephone and Telegraph Conference (WTTC). It is the ITU which co-ordinates the frequencies used for in satellite transmission from an orbital position.