GLOSSARY OF TERMS
ADSL - (Asymmetrical Digital Subscriber Line) is a technology for transmitting digital information at high bandwidths on existing phone lines to homes and businesses, hence is an ideal return path for digital TV.
CA (Conditional Access) - an encryption/decryption process, which provides access to the broadcaster's services and ensures secure purchase transactions for interactive services. Access is usually enabled by a 'smart card', activated by the broadcaster once a subscription is paid.
DAVIC (Digital Audio Visual Council) -a DVB-backed standard for interactive cable modems, also known as DVB-RC.
DigiCipher - the CA system owned by Motorola Inc.
DOCSIS (Data Over Cable Service Interface Specifications) - a standard interface for cable modems, the devices that handle incoming and outgoing data signals between a cable TV operator and a computer or television set.
DSL (Digital Subscriber Line) - a technology that enables existing copper telephone wiring to transfer digital signals, for example, television and internet content.
Decoder - the unit in a set-top box used to decrypt an encrypted television transmission.
DVB (Digital Video Broadcasting group) - digital television standardisation body for Europe.
EPG - Electronic Programme Guide.
Free-to-view - non-subscription television services i.e. television programming that can be accessed without CA.
HDTV (High Definition Television) - a high-resolution television display technology, currently being introduced in the US. It provides very high picture quality, using 720 or 1080 lines of resolution compared to the 525 lines in US standard definition television.
IDTV - Integrated Digital Television. The set-top box technology is integrated into the casing of a television casing to eliminate the need for a separate receiver decoder.
Internet Protocol - the method or protocol by which data is sent from one computer to another on the Internet. Each computer (known as a host) on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet. The same principle applies to set-top boxes that use IP to transport television and interactive services over telecoms or cable networks.
MMDS - Multi-point microwave distribution system.
MPEG - the Motion Picture Experts Group, MPEG (pronounced ehm-pehg), develops standards for digital video and digital audio compression. It operates under the auspices of the international Organization for Standardization (ISO). The MPEG standards are an evolving series, each designed for a different purpose.
MPEG2 - an international standard that enables the conversion of moving pictures into a highly compressed stream of digital data for transmission.
MPEG4 - a more advanced version of MPEG2 with greater compression capabilities. As a result, a higher quantity of television programming and interactive services can be delivered over the same network at the same quality. Also known as a low bit-rate streaming protocol.
Middleware - a layer of software or interface in the set-top box that allows applications such as interactive news and digital teletext to operate on all of the approved set-top boxes that may be running on a specific digital television network.
Multiplex - a frequency band carrying several channels, and sometimes additional data services, allowing a wide range of information to be carried on one signal.
PowerKey conditional access - the CA system owned by Scientific-Atlanta Inc. Scientific-Atlanta and PowerKey are registered trademarks of Scientific-Atlanta.
PVR (Personal Video Recorder) - a set-top box that includes a hard disk drive to provide digital quality recording, fast-forward and rewind and new features such as the ability to pause live TV.
SDTV - Standard Definition TV.
VoIP (Voice over Internet Protocol) - is the method by which voice is digitised and transmitted over Internet Protocol in digital packets rather than in the traditional circuit-committed protocols of the public switched telephone network.
Widescreen TV - a format which displays pictures in the cinema format, also known as 16:9 (for the ratio of breadth to length). It offers the advantage of allowing feature films to be broadcast in their original version.
XTV - the result of a collaboration between Pace and NDS, XTV is an integrated digital set-top box that includes a large amount of local storage. The smart software within XTV selects and stores programmes that the viewer is likely to want to watch, by interpreting meta-data inserted by the broadcaster at the head-end and comparing it with viewer preferences. In addition, XTV enables personalised playout so that the menu of both live and the stored content are in the order most likely to match the viewer’s taste and habits.
