T-DMB

T-DMB (Terrestrial Digital Multimedia Broadcasting) is an ETSI Standard (TS 102 427 and TS 102 428), and is a multimedia broadcasting system based entirely on terrestrial transmitters (unlike S-DMB which uses complementary satellite broadcasting).

T-DMB specifies MPEG-4 Part 10 (H.264) coding for video and MPEG-4 Part 3 BSAC or HE-AAC V2 for audio, the streams then being encapsulated in MPEG-2 TS packets, allowing multiplexing of the audio, video and other data. With Reed Solomon encoding and interleaving followed by OFDM-4DPSK (Orthogonal frequency-division multiplexing-Four-Phase Differential Phase Shift Keying), a T-DMB signal remains very robust to fading and masking effects.

The broadcasting mode is of the DAB (Digital Audio Broadcasting) terrestrial type, and therefore reliant on a large network of repeaters of which the cost is estimated at 40 million Euros for the city of Seoul alone in South Korea.

Tests and implementations

South Korea has a clear lead in the deployment of this technology. Six licences were granted in May 2005 by KBC (Korean Broadcasting Commission), including three T-DMB licences given to current conventional broadcasters (KBS, MBC and SBS) and three to other operators (the YTN news channel, CBD radio and an operator from industry). The South Korean T-DMB service has been broadcasting on VHF (band III of T-DAB) since the end of 2006. IT has 11 television channels, 25 radio stations and 8 data channels (push, alerts, etc.). The business model is based on the channels being free and financed by advertising. The Korean government estimated sales of 13 million terminals in 2009. By 1 June 2006, over a million T-DMB receivers had been sold with multiple deployments: mobile telephones, cars, laptop PCs, digital cameras etc.

Parallel tests took place in Europe, particularly in Germany where there is a large DAB network, but where commercial services have not taken off. The launch was well timed: the 2006 world football cup! STMicroelectronics in collaboration with Blaupunkt deployed a test network in 12 German cities, and mobile terminals such as the Samsung SGH-P900 were available. In France a consortium led by Bouygues Télécom, TF1, Samsung and VDL (a company specialised in digital radio broadcasting) carried out tests at the end of 2005.