DVB-SH

DVB-SH, Digital Video Broadcasting - Satellite services to Handhelds, is a physical layer standard for delivering IP based media content and data to handheld terminals such as mobile phones or PDAs, based on a hybrid satellite/terrestrial downlink and for example a GPRS uplink. The DVB Project published the DVB-SH standard in February 2007.

The DVB-SH system was designed for frequencies below 3 GHz, supporting UHF band, L Band or S-band. It complements and improves the existing DVB-H physical layer standard. Like its sister specification (DVB-H), it is based on DVB IP Datacast (IPDC) delivery, electronic service guides and service purchase and protection standards.

DVB-SH specifies two operational modes:

SH-A: specifies the use of COFDM modulation on both satellite and terrestrial links with the possibility of running both links in SFN mode.
SH-B: uses Time-Division Multiplexing (TDM) on the satellite link and COFDM on the terrestrial link.

Improvement of DVB-H

The DVB-SH incorporates a number of enhancements when compared to DVB-H:

More alternative coding rates are available
The omission of the 64QAM modulation scheme
The inclusion of support for 1.7 MHz bandwidth and 1k FFT
FEC using Turbo coding
Improved time interleaving
Support for antenna diversity in terminals

Recently, results from BMCO forum (Alcatel April 2008) shows a radio improvement of at least 5.5 dB on signal requirements between DVB-H and DVB-SH in the UHF frequencies. The improvements to signal requirements translates to better in-building penetration, better in-car coverage and extension of outdoor coverage. DVB-SH chipsets are being developed now by Dibcom and NXP, and are expected to be available in beginning of 2008. Initial specifications show that the chipsets supports both UHF and S-Band and are compatible with DVB-H.

Dibcom has announced a DVB-SH chip with availability in 2008 Q3. Dibcom DVB-SH 2008 Q3 The chip "has dual RF tuners supporting VHF, UHF, L-Band and S-Band frequencies".

Project organization

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.

Trials

DVB-H/SH trials are now underway in many cities and countries: Ireland, UK, Malaysia, Singapore, Helsinki, Berlin, Cambridge, Pittsburgh, Paris, Tehran, Madrid, Sydney, South Africa, Taiwan, The Hague, Brussels, Bern, Vienna, New Zealand, Philippines, Copenhagen, Budapest, Erlangen, and Sri Lanka.

Recently, the Indian regulator, TRAI, started to study DVB-SH as a major improvement of the DVB-H initial standard.

ICO, one of the biggest satellite operator in the United States, recently announced a nationwide deployment of an hybrid satellite/terrestrial network in DVB-SH with Alcatel-Lucent and Expway

DVB-SH in S-band is seen as a alternative in Europe. Recent field trials and studies showed better performance in radio than DVB-H standard that would lead to much cheaper costs for network deployments.

In France again, SFR and Alcatel-Lucent teamed up to deploy a DVB-SH trial. The results confirmed the theorical assumptions on the superiority of the DVB-SH to DVB-H, being the natural evolution of this legacy one.

In Italy, 3 Italia, RAI and Alcatel-Lucent joined forces for the first DVB-SH trial in Italy.

In US, Dish Network and Alcatel-Lucent joined forces for the first DVB-SH trial in US.