National Grid Wireless begins DAB-IP and T-DMB trial

09 September 2006

National Grid Wireless, one of the UK's leading providers of broadcast infrastructure, has begun technical trials of DAB-IP and T-DMB, two of the bearer technologies, which could be adopted for the provision of mobile media services in the UK.

The services are being transmitted on the Stoke-on-Trent DAB multiplex and carry video and audio content supplied by the operators of the multiplex, UTV-Emap Digital. The technical trial is monitoring the relative performance of both technologies in rural and urban areas, including within buildings. The trial will enable the company to determine the full requirements for the introduction of enhanced data services onto conventional T-DAB platforms.

The multiplex system has been provided by RadioScape and is currently the only system operating that supports both T-DMB and DAB-IP. The video encoding system has been provided by Pixtree.

Mark Watkins, director, mobile media, at National Grid Wireless, said: "This work supports our stated objective of being able to deliver a range of technologies that meet the network needs of our customers. At the same time this trial is providing us with invaluable information that we will be able to utilise in the design and implementation of the mobile media networks of the future."

National Grid Wireless will release the results of the trial in late 2006.

Information Sheet: Download PDF (663kb)

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Notes to Editors:

About National Grid Wireless

National Grid Wireless is a wholly owned subsidiary of National Grid and is the leading independent provider of infrastructure to the mobile telecommunications operators in the UK.

National Grid Wireless is also one of two UK providers of terrestrial infrastructure for the transmission of analogue and digital television and radio broadcasts in the UK and as such achieves a 98% population coverage. In addition to the traditional analogue services, National Grid Wireless has a strong position in the growing digital television market, owning two of the six digital terrestrial television licences and providing infrastructure services to all the Freeview channels and the BBC and BSkyB.

About RadioScape

RadioScape® Ltd. is the world's only developer of end-to-end digital audio broadcasting solutions giving RadioScape unmatched systems knowledge and enabling it to ensure that customers receive the highest levels of quality, robustness and reception at all stages.

Its DAB Multiplex systems are used extensively throughout the world and currently are market leaders in Mobile TV via DAB.

Founded in 1996, RadioScape's investors include Atlas Ventures, Royal Bank Ventures Investments, Scottish Equity Partners, JAFCO, Texas Instruments, Yasuda Enterprise Development, iGlobe Partners, Psion and Arqiva. RadioScape is headquartered in London, England with offices in Singapore and Hong Kong. For more information, please visit http://www.radioscape.com.

RadioScape is a registered trademark and Software Defined Digital Radio is a trademark of RadioScape Limited. All other trademarks are acknowledged.

For further information:

Stephen Arnold
National Grid Wireless
+44 (0) 1926 416 870
+44 (0) 7803 887 288 (m)

An introduction to DAB-IP and T-DMB

IP-DAB has been developed in the UK and Europe for the delivery of packet mode audio/video/data services to handheld portable devices over a Eureka147 bearer platform. Windows media 9/10 audio/video encoding is used to encode the source content. Windows ASF (Advanced streaming Format) is used to stream these components as UDP/IP. The UDP/IP packets are formed into DAB data groups, before additional Reed Solomon outer coding and interleaving is applied (Enhanced Packet Mode). The Enhanced Packet Mode service is then injected onto The DAB MSC (via an IP-gateway) as a stream mode service.

Driven by the UK market, the IP-DAB Windows video component can be configured to operate at a very low bit rates. This essential for the UK broadcast industry where the total bit rate allowance for data services is strictly regulated to 30% of the total bit rate allocation on a T-DAB platform.

T-DMB has been developed by the Korean broadcast industry for the delivery of audio/video and data services over a Eureka147 DAB bearer platform. The Source encoding for the T-DMB service uses MPEG4 BSAC or AAC for the audio component, and MPEG4 H.264 for the video component. The audio and video components are multiplexed into an MPEG2 transport stream. The MPEG2 TS has additional Reed Solomon (RS) and interleaving applied, before injection via a T-DMB gateway onto the DAB MSC as a stream mode service.

The audio - data bit rate provision and service allocation on a standard T-DAB multiplex in Korea is not subject to strict guidelines (as for example in the UK). Therefore it is common to receive T-DMB services, with a video service component in excess of 256Kbit/s. However T-DMB can be configured to operate at much lower bit rates, as demonstrated in Europe, where the video bit rate component is configured to operate at approximately 150 - 200 kbit/s.