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A proprietary operating system for interactive services.

Media Home Platform. An operating system (sometimes called "middleware") used in digiboxes for interactive services via satellite, terrestrial and cable networks. MHP is a relatively new, open standard advocated by all Nordic public service companies (SVT, DR, YLE, NRK). MHP allows many possibilities and is currently available in several versions.

The alteration of a carrier wave in relation to the value of the data being transferred. Analogue satellite transmission use FM modulation. Digital satellite transmission use QPSK modulation.

Moving Pictures Experts Group. An International Standards Organisation sub-group which developed a standard (MPEG-2) for the digital compression and multiplexing of video and audio signals.

Or Yagi Aerial. A conventional aerial used to receive terrestrial television.

To transmit a message to a select group of recipients. A simple example of multicasting is sending an e-mail message to a mailing list. Teleconferencing and videoconferencing also use multicasting, but require more robust protocols and networks. Standards are being developed to support multicasting over a TCP/IP network such as the Internet. These standards, IP Multicast and Mbone, will allow users to easily join multicast groups. Note that multicasting refers to sending a message to a select group whereas broadcasting refers to sending a message to everyone connected to a network. The terms multicast and narrowcast are often used interchangeably, although narrowcast usually refers to the business model whereas multicast refers to the actual technology used to transmit the data.

Verb:To combine two or more independent signals into one transmission channel. Noun: The combined digital signals transmitted on one satellite transponder.