DVB-H (Digital Video Broadcasting – Handheld) is technology standardised by the ETSI (European Telecommunications Standards Institute) in 2004 (EN 302 304). It is the main competitor to DMB (Digital Multimedia Broadcasting) systems and is above all a development of DVB-T (Digital Video Broadcasting – Terrestrial), the standard for delivering multimedia content to fixed terminals.
New features compared to DVB-T
To cater for mobile use, three new features have been added:
• The data stream is sent by time sharing in the form of bursts, allowing the receiver to consume less energy (by a factor of 10 according to some estimates) when on standby;
• An MPE-FEC type error code has been introduced (data bit redundancy and RS type data protection) to guarantee good reception quality even at high speeds or during handovers;
• A new set of modulations: Q-PSK, 16-QAM and 64QAM.
This gives a particularly robust signal, improving reception quality at ground level
Compression and frequency bands
The video compression standard is not specified, but can be of the MPEG-4, MPEG-2 or VC-1 types. The UHF frequency bands (IV and V) make it possible to have an aerial small enough to fit inside mobile telephones. Tests have also been carried out on the L band in the USA. Speeds of 11 Mb/s are claimed for DVB-H.
A very important advantage of DVB-H is its very close similarity to DVB-T: the same modulators/transmitters/antennas can be used and synergies can be set up for the manufacture of receivers and for extending the coverage area of one of the two standards to work alongside the other to facilitate its deployment.
DVB-H also goes hand in hand with the "IP Datacast Forum", of which the objective is to promote IP technology for broadcasting any IP content on the DVB-H layer, thereby facilitating network interconnection and digital convergence.
Tests and deployments
Europe is clearly oriented towards DVB-H, on which more channels can be received than on DMB (around thirty compared with a dozen). The receivers are also more energy-efficient (consumption three times lower).
There have been many experiments worldwide: Germany, Italy, Australia, South Africa, the USA etc. In Italy a commercial service was launched during the World Cup but some analysts are uncertain as to its success. Coverage is said to be about 65% of the population. In England there is a commercial service for around 16 video channels.
In France, tests were carried out by the mobile operators including a consortium led by SFR and Canal+ since 2005. However, in the face of low demand, Spain, Switzerland, Germany and France have either closed or not launched services. In the UK, a survey showed that there is potential for such a service. Broadcasting would be on the UHF bands (cf. the complementarity of DVB-T and DVB-H).