The DVB Steering Board has approved the DVB-SH (Satellite services to Handhelds) specification. Two documents were approved: a waveform specification and a description of the system. The specification was developed by the DVB Technical Module’s TM-SSP working group.
DVB-SH is defined as a system which is able to deliver IP based media content and data to handheld terminals like mobile phones and PDAs via satellite. Whenever a line of sight between terminal and satellite does not exist terrestrial gap fillers are employed to provide the missing coverage. The DVB-SH system has been designed for frequencies below 3 GHz, typically in the S-band. It complements the existing DVB-H physical layer standard and like its sister specification (DVB-H) uses the DVB IP Datacast (IPDC) set of content delivery, electronic service guide and service purchase and protection standards.
DVB-SH includes features such as turbo coding for forward error correction and a highly flexible interleaver in an advanced system designed to cope with the hybrid satellite/terrestrial network topology. Satellite transmission ensures wide area coverage, with a terrestrial component assuring coverage where the satellite signal cannot be received, as may be the case in built-up areas. DVB-SH in fact specifies two operational modes. SH-A specifies the use of COFDM on both satellite and terrestrial links with the possibility of running both links in SFN mode. SH-B uses a Time Division Multiplex (TDM) on satellite with COFDM on the terrestrial link. A comprehensive set of guidelines for the implementation of the standard will follow.
The DVB-SH specifications will now be published by the DVB Project and forwarded for formal standardisation at the European Telecommunications Standards Institute by its Joint Technical Committee Broadcast.