DVB-H

From Wikipedia, the free encyclopedia

DVB-H (Digital Video Broadcasting - Handheld) is a technical specification for bringing broadcast services to handheld receivers. DVB-H was formally adopted as ETSI standard EN 302 304 in November 2004. The DVB-H specification (EN 302 304) can be downloaded from the official DVB-H website. DVB-H is officially endorsed by the European Union.The major competitor of this technology is Digital Multimedia Broadcasting (DMB).





Technical explanation
---------------------------------------------------------------
It is the latest development within the set of DVB transmission standards. DVB-H technology is a superset of the very successful DVB-T (Digital Video Broadcasting - Terrestrial) system for digital terrestrial television, with additional features to meet the specific requirements of handheld, battery-powered receivers.

DVB-H can offer a downstream channel at high data rates which can be used as standalone or as an enhancement of mobile telecommunication networks which many typical handheld terminals are able to access anyway.

Time slicing technology is employed to reduce power consumption for small handheld terminals. IP datagrams are transmitted as data bursts in small time slots. Each burst may contain up to 2 Mbits of data (including parity bits). There are 64 parity bits for each 191 data bits, protected by Reed-Solomon codes. The front end of the receiver switches on only for the time interval when the data burst of a selected service is on air. Within this short period of time a high data rate is received which can be stored in a buffer. This buffer can either store the downloaded applications or playout live streams.

The achievable power saving depends on the relation of the on/off-time. If there are approximately ten or more bursted services in a DVB-H stream, the rate of the power saving for the front end could be up to 90%. DVB-H is a technical system which was carefully tested by the DVB-H Validation Task Force in the course of 2004 (see ETSI Technical Report TR 102 401).

Frequencies
---------------------------------------------------------------
DVB-H is designed to work in the following bands:

-VHF-III (170-230 MHz, or a portion of it)
-UHF-IV/V (470-862 MHz, or a portion of it)
-L (1.452-1.492 GHz)
DVB-H can coexist with DVB-T in the same multiplex.

DVB-IPDC
---------------------------------------------------------------
The set of DVB specifications for IP Datacasting (DVB-IPDC) can most simply be described as the essential components required to deploy a commercial mobile TV service based on Internet Protocol. DVB-IPDC is a set of systems layer specifications originally designed for use with the DVB-H physical layer, but that will ultimately be used as a higher layer for all DVB mobile TV systems, including DVB-SH, and indeed as a higher layer for any other IP capable system.

In short, with regard to mobile TV, these specifications define what is delivered, how it is delivered, how it is described, and how it is protected. They cover system architecture, use cases, DVB PSI/SI signalling, electronic service guide (ESG), content delivery protocols (CDP), and service purchase and protection (SPP). Almost all of these have now been published as formal ETSI standards. The full set of DVB-IPDC specifications is available from dvb-h.org.

DVB-SH
---------------------------------------------------------------
DVB-SH (satellite services to handheld devices) is a hybrid (satellite/terrestrial) standard derived from DVB-H and ETSI SDR. A similar architecture is already being used in S-DMB, XM Satellite Radio, Sirius Satellite Radio, MobaHo! but DVB-SH promises to be more powerful. The envisaged system incorporates a high power geostationary satellite for outdoor and light indoor coverage integrated with a terrestrial repeater (low power gap-filler) network for indoor coverage in urban areas.

Alcatel-Lucent expects to deliver DVB-SH terrestrial repeaters in 2007. Eutelsat and SES ASTRA plan to launch an S-band satellite covering Europe in 2009. DVB-SH satellite services will become operational in 2009 but maybe DVB-SH operations will start earlier with terrestrial networks in certain regions of the world. Chip maker DiBcom is designing a chipset that will be compatible with the DVB-H standard working in the S-Band, Sagem is developing DVB-H phones that support both UHF and S-Band. It's an official DVB Project standard. The DVB Technical Module launched a Study Mission on SSP (Satellite Services to Portable Devices) and in June 2006 TM-SSP started to develop standards. The DVB Project approved the definitive standard in February 2007.

French Agence de l'innovation industrielle is now financing this effort through TVMSL, a project led by Alcatel-Lucent that plans to develop a DVB-SH standard suitable for hybrid satellite and terrestrial transmission. Other partners involved in TVMSL are Sagem, Alenia, RFS, Philips, DiBcom, TeamCast, UDcast, CNRS, INRIA, CEA-LETI.

DVB-H2
---------------------------------------------------------------
A study mission on a possible DVB-H2 system is due to commence in 2007 which could produce a finalized specification in 2008. It is not unthinkable that DVB-H2 and DVB-T2 specifications will be interrelated systems.

Service launches
---------------------------------------------------------------
In Albania, DigitALB launched nationwide Service on 20 December 2006 with the product commercially available from 21 April 2007.

In Finland, the license to operate a DVB-H network was awarded to Digita in March 2006. In May 2006 they announced that they had signed a contract with Nokia to use its DVB-H platform for the service. The network was supposed to be launched on the 1st December 2006, but disagreements regarding copyrights of the broadcasted material have stalled the launch. Among the services available will be Voice TV and Kiss digital radio.Initially the network should cover 25% of the population with coverage area Helsinki, Oulu and Turku. Mobiili-TV started commercial services on May 10 2007.

In India, Indian public broadcaster Prasar Bharti (also known as DD for Doordarshan) has teamed with Nokia to start a DVB-H. And trial is going in various metropolitan areas to test the reception quality of the broadcast coverage. Moreover, DD is currently broadcasting 8 channels in the New Delhi.

In Italy, 3 Italia launched nationwide services in May 2006, both Telecom Italia Mobile (TIM) and Mediaset in June 2006, Vodafone in December 2006.

In Singapore, TVMobile uses DVB technology to broadcast live news, entertainment and music content directly to over 1500 Singapore Bus Service buses islandwide, along with various other indoor and outdoor locations.

In the United States, a nationwide service will be rolled out by Modeo a company owned by Crown Castle. The service will begin in 2006 in New York City and will roll out to the top thirty markets in the USA during 2007. Modeo owns 5 MHz of spectrum nationwide at 1600 MHz. At the NAB trade show in April 2006, a second service launch was announced by SES Americom and Aloha Partners. Titled Hiwire Mobile Television, the service is set to begin trials in Las Vegas in Q4 2006. Hiwire owns two 6 MHz channels of spectrum at 700 MHz covering most of the country.

In Vietnam, VTC launched nationwide service on 21 December 2006.

O2 Ireland commenced a trial in March 2007 with a single high site 1.2 kW transmitter at Three Rock covering the greater Dublin area.

In France, Spain and South Africa nationwide service launch is planned for 2007, in Austria, Germany and Switzerland for 2008.

In China two companies have been issued licenses by the government, Shanghai Media Group and China Central Television. Trials are currently underway, with service launch expected before the 2008 Beijing Olympics.

Read More......