CANAL+ TECHNOLOGIES and the world's first digital terrestrial television service in the United Kingdom

10th November 1998

The world's first digital terrestrial television service, which started broadcasting in the United Kingdom on November 15, is supported to a great extent by CANAL+ digital technology.

The UK digital terrestrial operator ONdigital chose CANAL+'s MEDIAGUARD conditional access system and MEDIAHIGHWAY interactive software after making a call for bids in 1997. MEDIAGUARD and MEDIAHIGHWAY are Europe's two most successful technologies for digital TV and already equip an installed base of more than two million set-top boxes. CANAL+ was also selected to be the main systems integrator for ONdigital's technical installations based on its experience in designing and creating digital broadcasting centers in several European countries.

As part of its partnership with ONdigital, CANAL+ has also been asked to develop a common scheduling information system (DVB-SI) for all the digital terrestrial operators in the UK. Lastly, through ONdigital, several other UK providers of digital terrestrial pay-TV are also using MEDIAGUARD for conditional access.

The new digital terrestrial television service reached 70 per cent of homes in Great Britain and Northern Ireland at launch and will rise to 90 per cent by the end of 1999. Six "multiplex" channels have been allocated to the service, three to existing terrestrial television providers and three to ONdigital, a partnership between Carlton Communications and the Granada Group, who each own 50 per cent of the company.

Digital terrestrial television in the UK

The Independent Television Commission (ITC) has allocated six "multiplex" channels each capable of broadcasting five or six TV channels simultaneously using digital compression technology. Three were attributed to existing terrestrial television providers and three were sold in competitive bidding in June 1997 to British Digital Broadcasting (BDB), a partnership between Carlton Communications and the Granada Group, who each own 50 per cent of the company. BDB has since been renamed ONdigital.

The new digital terrestrial TV service reaches 70 per cent of homes in Great Britain and Northern Ireland, rising to 90 per cent by the end of 1999.

Digital television in the UK

  • BBC: BBC 1, BBC 2, BBC News 24, BBC Choice, BBC Learning/Information, BBC Digital Teletext
  • Digital 3&4: ITV, ITV 2, ITV 3, Channel 4, FilmFour°, Teletext
  • SDN: Channel 5, S4C, other channels and services still to be defined, some of which will be pay-TV
  • ONdigital: Carlton Cinema, Carlton Select, Carlton Food Network, Eurosport, Granada Breeze, UK Gold, UK Play, Carlton Kids, Carlton World, Granada Plus, Granada Men & Motors, UK Style, UK Horizons, Cartoon Network, Sky One, Shop!, First Ondigital, Sky Sports 1, Sky Sports 3, Sky Movie Max, Sky Premier, FilmFour

One of the innovative features proposed by ONdigital is an "a la carte" basic offer. Subscribers may choose six channels from a total of 12 for a monthly fee of £7.99, or pay £9.99 a month for the whole tier. During a special introductory period, all 12 channels will be available for £7.99. Premium channels can also be chosen "a la carte", with FilmFour available for £6 a month, one Sky channel for £11, two Sky channels for £15, and three for £18.

Other special features available to ONdigital subscribers include an on-screen service that gives viewers information on current and upcoming programs, a surfing function for choosing between the channels, and a parental lock. ONdigital also plans to launch pay-per-view and e-mail services in the near future. With a view to this development, all the digital set-top boxes on sale today for £199 are equipped with a modem.

Digital terrestrial television offers premium quality sound and pictures, while digital compression techniques make it possible to broadcast an ever greater number of channels, as well as new on-line and interactive services, and programs in 16:9 format. Viewers can receive the digital terrestrial broadcasts without installing a satellite dish or hooking up to the cable network. In most cases, the indoor or outdoor aerials used for conventional terrestrial analog TV will also receive the new digital signals.

This is a particularly exciting period in the UK television market. The country already has a large number of analog channels, in particular via satellite. In the space of a few months, this base will be broadened with digital channels delivered terrestrial, via satellite (Sky Digital since October 1) and by cable.

Several other European countries are in the process of introducing digital terrestrial TV. Sweden will probably be the next to launch such a service, sometime next year. The country has attributed two multiplexes to different operators, including CANAL+ Nordic, the only pay-TV channel in the package. In France, TDF has been operating a pilot digital terrestrial TV service in Brittany since September, to which CANAL+ is associated.

CANAL+ agreements with ONdigital

ONdigital selected CANAL+ digital technology and broadcasting expertise following a call for bids in 1997.

In February 1998, Société Européenne de Contrôle d'Accès (SECA), a 50-50 subsidiary of CANAL+ and Bertelsmann, signed an agreement to supply ONdigital with the MEDIAGUARD conditional access system. In May, CANAL+ agreed to provide ONdigital with its MEDIAHIGHWAY interactive software incorporating the MHEG-5 graphic interpreter, which was adopted by the Digital Terrestrial Group (DTG) as the UK's standard for digital terrestrial TV.

CANAL+ has since signed two other important agreements. One is for the design and implementation of a centralized program information management system, which will be used for electronic programming guides by all the UK's digital terrestrial TV operators. The other makes CANAL+ principal systems integrator for all of ONdigital's digital installations, including signal compression and multiplexing.

CANAL+ had several advantages to offer to ONdigital:

  • When ONdigital launched its call for bids, CANAL+ digital technology had been in use for two years, first in France, and then in other European countries. ONdigital needed to launch its service very quickly and CANAL+ responded with tried and tested systems.
  • Tests carried out by independent consultants at ONdigital's request showed that CANAL+'s MEDIAGUARD conditional access system was one of the most reliable and secure.
  • MEDIAHIGHWAY is currently the only interactive system in the market that is flexible and open enough to handle the technical solutions and standards selected for digital terrestrial TV in the UK, notably the incorporation of the MHEG-5 graphic interpreter.
  • MEDIAHIGHWAY's virtual machine technology makes it one of the few systems that can be immediately integrated into different hardware platforms running with different operating systems, thereby enabling ONdigital to meet its intention to select several manufacturers from the outset for its set-top boxes.

Numerous challenges and little time

To get the world's first digital terrestrial television service up and running, some sixty CANAL+ TECHNOLOGIES engineers have been working on the project over the past six months.

Following the signature of the MEDIAGUARD contract in February 1998, ONdigital selected its set-top box manufacturers including some which had not yet been licensed by CANAL+. After signing the MEDIAHIGHWAY contract in May, CANAL+ had about three months to integrate the MHEG-5 graphics interpreter into its interactive software and deliver this customized MEDIAHIGHWAY version to the digital set-top box manufacturers. First digital receiver trials started in September.

Although the project uses several international standards (MPEG-2 for digitization and signal compression, DVB-T for digital terrestrial broadcasting), this is the first time that the different systems have to be interfaced and operational on such a large scale.

Terrestrial digital television differs in several ways from the satellite- and cable-based digital TV already available in several other countries:

  • While the number of channels delivered by satellite and cable can be fairly easily increased by adding broadcasting capacity (for example, with additional transponders), digital terrestrial broadcasting is strictly limited by a finite number of frequencies. Since analog services will need to be maintained for some time, there are only a small number of frequencies available for digital terrestrial TV at present. This means that available bandwidth must be managed for maximum efficiency.
  • Compared with satellite TV, where multiplexed programs are transmitted directly to the satellite from the digital broadcasting center, digital terrestrial broadcasting requires a large network of transmitters (81 for the UK service) that have to be supplied with the right digital signal individually.

Centralized program information management

All information concerning digital programming, such as program start and finish times, program titles, content synopses, and channel schedules, is organized using a standard format defined by the Digital Video Broadcasting Project Group (DVB), referred to as DVB-SI. This data can be used to feed electronic program guides or applications such as CANALSATELLITE Numérique's Pilot system, which gives viewers on-screen information on current programs at the touch of a button.

Because of the restricted bandwidth available for digital terrestrial TV broadcasting, the UK regulator (ITC) ruled that all the operators share the same flow of data. This means collecting information from different sources and ensuring that it complies with DVB standards. What is more, the numerous regional programming slots offered by some operators requires precise routing of program information from the central database to the transmitters serving the region concerned. The complex task of developing software to compile and rout this information has been entrusted to CANAL+. The system, which serves the entire UK digital TV industry, is hosted by ONdigital.

CANAL+ , ONdigital's principal systems integrator

ONdigital chose CANAL+ to provide a systems integrator role for its digital broadcasting center in London because of its experience in designing and creating digital broadcasting centers, beginning in France at the end of 1995 and then in other European countries, including Spain and Belgium. CANAL+ has advised ONdigital on what technology to use, has designed the basic architecture of the digital broadcasting center and supervised its installation.

The different channels in the ONdigital bouquet are transmitted from the production units of Carlton, Granada, BSkyB and BBC/Flextech to the digital broadcasting center in London, via an extensive network of fiber optic cables. The signals are then compacted using DiviCom equipment based on the MPEG-2 international standard and multiplexed on three channels.

At this point, all of MEDIAGUARD's encryption data is added, based on the subscriber management system and in liaison with ONdigital's subscriber call center in Plymouth. At the same time, certain encryption data is transmitted to the digital broadcasting centers of other terrestrial operators so that they can broadcast their own scrambled channels. This is already the case for Digital 3&4 for the FilmFour pay-TV channel, which is marketed by ONdigital but broadcast on the digital frequency used by ITV and Channel Four. SDN, another UK digital terrestrial operator, is expected to use MEDIAGUARD encryption technology in the near future as well. While technically and contractually speaking, all the conditional access operations are handled by ONdigital, it is fair to say that MEDIAGUARD has made a place for itself as the conditional access system of choice for the UK's digital terrestrial TV industry.

ONdigital's three multiplexed data streams are then relayed to the transmitter network covering Great Britain and Northern Ireland, which will eventually include 81 transmitters. Transmission is ensured by a fiber optic network managed by British Telecom, while Castle Transmission International is responsible for the transmitters. All the incoming and outgoing connections to the digital broadcasting center are backed up by a duplicate so that technical problems do not interrupt the transmission of programs.

Five set-top box manufacturers

To receive digital terrestrial television, viewers need a set-top box to decompress the digital signal and convert it into an analog signal usable by conventional TV sets. The same set-top box is also used to unscramble pay-TV programs.

One of the major advantages of the MEDIAGUARD and MEDIAHIGHWAY systems is that they can be easily integrated into a wide variety of hardware and software platforms, thanks to their modular architecture and the virtual machine technology used by MEDIAHIGHWAY.

ONdigital has initially chosen five manufacturers (Pace, Philips, Sony, Nokia, and Toshiba) to supply the set-top boxes, which will retail at £199. These manufacturers are among 20 companies licensed today to use CANAL+'s MEDIAGUARD and MEDIAHIGHWAY software.

A number of manufacturers, including Philips and Sony, have already announced that they will soon begin marketing television sets with built-in set-top box functions in the UK.

One of the advantages of the new generation digital set-top boxes developed for the ONdigital service is that the operator can download all of the MEDIAGUARD and MEDIAHIGHWAY software if necessary, as well as updated versions of the manufacturer's operating system, without worrying about pirating, thanks to a sophisticated authentication procedure performed by the set-top box.


CANAL+'s conditional access and interactive software are the leading technologies for digital TV in Europe today. More than two million set-top boxes are equipped with the software and, given the order backlog at CANAL+ accredited manufacturers, this figure should rise to close to three million by the end of 1998. The software is already used by operators in 11 European countries.

CANAL+ is also exporting its digital broadcasting technology outside Europe. Last September, CANAL+ TECHNOLOGIES signed agreements for digital TV projects in Israel (Unicorp's NewS@t project planned for 1999) and Brazil (with KTV Communicacoès). Earlier in the year, CANAL+ TECHNOLOGIES signed an agreement with a Taiwan-based operator. Through Havas Overseas, the Mediasat set-top boxes are also used in the West Indies and in Réunion. CANAL+ TECHNOLOGIES, which employs more than 250 highly trained engineers, has built up strong expertise and credibility in the industry. Proof of this lies in the agreement signed last August with consumer electronics manufacturer Pioneer and US-based DiviCom (digital compression and multiplexing) and C-Cube (chip design and manufacturing).

This agreement, which does not preclude future partnerships with other manufacturers, will enable CANAL+ to provide end-to-end solutions to digital TV operators around the world and notably in North America. The MEDIAHIGHWAY interactive software will be as easy to adapt to US standards (OpenCable, ATSC, ...) as it was to meet the UK requirements.