Nokia boxes in Sweden, DTT......................................
tvbeurope.com
Digital Terrestrial Ttelevision for Sweden
by Erik Dillner, Launch Manager, Teracom
Since 1992 Teracom AB, which operates Sweden's analogue broadcasting network, has been developing and promoting digital television. It has also played an active role in HD television and introduced digital radio in 1995. From 1 January 1999, Teracom is launching a Digital Terrestrial Television service (DTT) that, in addition to conventional television, will offer interactive facilities, information services, electronic purchasing and similar Internet-like features, some of which will be available from early 1999.
In 1997, after studying its desirability and feasibility, the Swedish government decided to introduce DTT and began awarding licences. Supporting a medium that could offer Swedish content, the government felt that the public should have a choice between cable, satellite and terrestrial digital TV.
Responsibility for the technical platform, including digital signal multiplexers, was given to Teracom; conditional access control will be co-ordinated separately by Senda (using the Viaccess system). Thomson Broadcast Systems was one of those chosen to supply and install Teracom's MPEG-2/DVB-T system in the framework of the first phase of the project. The Thomson solution consists of MPEG-2/DVB encoders, re-multiplexers (DBX 2200), ATM Network Adaptors (TNA 4600), as well as control and command software (DBS 2930) and SI management of the whole primary distribution network.
Teracom started digital transmissions over one DTTV network in August 1997, from three transmission sites. In December 1997 the number of transmission sites was increased to cover 50% of the population with one network. Testing of two networks with a coverage of 50% of the population is currently underway. The first stage of the DTTV service, which goes on-air in January, includes two networks each carrying four services, i.e. a choice of eight digital services at any time.
Initial programmes will be Swedish Television's SVT1 service, the new SVT24 round-the-clock news, the existing TV4, TV3 alternating weekly with Kanal 5, Canal+, TV8 sharing with Cell Digital TV (a new interactive TV service), and Knowledge Network sharing with local services. Swedish TV and TV4 will provide many of the regional and local services, others coming from two new local broadcasters Landskrona Vision and Lankomedia. Broadcasters initially sharing channels will have priority in future allocations, when new networks have been built, thus putting an end to sharing.
A third network (four more services), using Thomson Broadcast equipment, is expected to start up in April 1999 and a fourth network in the autumn of 1999, both subject to political decisions. Coverage will then be expanded to about 70% by September 2000 and subsequently nearly the whole population. Six digital networks may eventually be available and phasing out of existing analogue networks is expected to take place in around ten years time.
Return channel
An innovative feature of Sweden's DTTV network will be interactivity, widely seen as a major attraction. The telephone network can be used for return channel communication.
To demonstrate how interactive programmes might work, Teracom and Swedish Television have developed Dreamplay, based on a conventional quiz programme; viewers can participate instead of simply watching, and scores can be displayed for competitors in and out of the studio.
Direct purchasing via TV is attractive both for the viewer and large national companies. Instead of responding by post, the viewer can do so via the TV remote control, having seen the product on-screen. Cell Digital TV, one of the first DTT broadcasters and a member of the Cell Internet Commerce Development Group, is pioneering electronic selling in Sweden; it regards DTT as a potentially broader medium than the Internet, since virtually every household has a TV. Cell DTV sees applications in the areas of electronic banking, e-commerce, interactive advertising and various types of information services.
Initially, the main means of accessing DTT for most viewers will be Set-Top Boxes (STBs). Units from Nokia will cost around SEK 5,000 (approximately $650), including tax. Pace, Sony and other manufacturers are expected to launch STBs shortly.
One anticipated development is that retailers will make bundled offers of 16:9 sets and STBs. Future receivers are likely to include a simpler 'kitchen' set with built-in DTT receiver and perhaps also monitors to be used in combination with STBs. SVT24 is prepared for and very likely to produce programmes in 16:9 from the outset, while other broadcasters have indicated plans for a transition to 16:9.
Innovative distribution
From the outset, SFN (Single Frequency Network) technology seemed particularly attractive for the digital network because of its efficient use of the spectrum. Southern Sweden (SkŒne) will be covered by two main stations working in SFN, with smaller transmitters in Stockholm, also using SFN, to increase the signal level locally. In the first phase there will be ten transmitter sites, the first DTT network in Europe to use SFN technology and 8K COFDM modulation. This compares with Teracom's present analogue network's 54 main stations and 600 slave stations, all requiring frequency co-ordination.
The primary distribution network will use SDH, together with the latest generation Thomson ATM Network Adaptors, encoders and multiplexers with complete re-multiplexing, basic MPEG-2 switching capability and interface to the Viaccess Conditional Access system. The Network Adaptors will be used for interfacing the MPEG-2 transport stream to the PDH/SDH network, to feed the transmitter sites with national and local services from content providers. Flexibility over bit-rate and transmission resource optimisation are among several advantages of this open technical solution.
The Thomson MPEG-2 system will be controlled and monitored from a powerful SNMP-based remote Central Management System; this will also control local to national switching, using In-band Processing (not in the first stage) as well as Cross-SI distribution at the re-multiplexing sites. Switching will in the future be operated by a content provider from its own automation system in the continuity studio. Another important factor for Teracom's decisions regarding future investment in equipment will be support for bitrate regulation and control, as well as local insertion.
Looking ahead
After full coverage early in the millennium, the next stage is expected to be expansion to six networks providing 24 services, before analogue television is phased out. Teracom is confident that in the new information society, which has seen such rapid growth in mobile phones and Internet trading, DTT will be a major vehicle for information and interactive operations for people everywhere.
In a country where 90% of foreign programmes are transmitted in the original language, it will make it much easier to offer a whole range of programmes from companies including MTV and CNN (already popular), to suit a broad range of tastes and interests. The Digital Show in Stockholm at the end of October, as well as road-shows for dealers, have had a response beyond what we ever hoped for. The message coming back through the media is definitely: DTT is here to stay. The Teracom system is likely to become a reference for other national DTT broadcasters.
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