DVB-H versus 3.5G Wireless

Europe UK: If the cellular industry has its way, we should soon have access to live TV transmissions on our 3G mobile phones.

How the TV signals reach the mobile, however, depends on which standards are adopted - Brian Lancaster, a commercial engineer with AlanDick, the broadcast and communications infrastructure specialist, explains the technology behind this quiet revolution…

June 2006 will be an important date for football fans the world over - it's the start of the World Cup, which takes place in Germany.

That dateline will also be an important one for the global cellular industry as well, as most leading-edge networks want to have their real-time TV-on-a-mobile services operational by then.

But relaying TV - and video-on-demand services - to a cellular handset involves a lot more than building an analogue or digital TV tuning system into the mobile.

As users of handheld TVs will have discovered, TV signals do not propagate well to TVs on the move.

The cellular networks must instead turn to new technologies such as DVB-H (Digital Video Broadcasting - Handheld) and 3.5G transmissions to meet their needs.

Following its ratification by the European Technical Standards Institute (www.etsi.org), DVB-H has moved off the drawing board and into the real world, with a consortium of European firms – including Nokia, MTV and YLE (a Finnish broadcasting company) – already trialling the technology in Finland.

The DVB-H/IP datacasting trial, which started in early March, gives Finnish triallists real-time access to a cluster of TV channels, including BBC World, CNN, Eurosport and MTV, on Nokia 7710 handsets equipped with a plug-in transcoding device.

DVB-H, however, is more than just receiving digital TV transmissions. The technology, like digital terrestrial and satellite, allows users to receive ancillary files, including pictures, video clips and music, for viewing and listening on the move.

Unlike digital terrestrial and satellite transmission standards, however, DVB-H uses a `data burst' or time-slicing approach to the carriage of signals across the available radio spectrum.

Using this transmission technology reduces DVB-H power consumption on mobile phones to roughly the same level as a voice call, although the handset vendors are still working hard to develop lower-power display screens.

Unlike 3.5G technology, more of which in moment, DVB-H does not use the normal cellular transmission path to carry the real-time TV signals to the mobile.

Signals are, instead, carried across a separate network, although it is expected that the base stations for commercial DVB-H deployments will be co-located, where appropriate, with existing GSM and/or 3G base stations.

DVB-H's main claim to fame is that it supports frame rates of up to 25 frames per second (fps), compared to the 5 fps seen on existing video streaming services. Standard TV broadcasts operate at between 25 and 30 fps.

The difference between streamed video files seen on mainstream 2G and 3G mobiles (and networks) at the moment was clearly illustrated at the giant CeBIT show in Germany recently, when Siemens showed off its DVB-H prototype handset.

At the show, held in Hanover during March, Siemens showed its prototype handset sending text messages at the same time as receiving a DVB-H transmission.

The Siemens prototype also had an integral 128 megabytes of memory for program storage, as well as a memory card slot for expanded storage facilities.

Here at AlanDick we think that the interactive element of DVB-H has significant potential. Users of a mobile could, for example, watch a series of film trailers on their handset and then reserve a seat at the movies using the return data channel.

Vodafone Germany is planning to stage a trial of DVB-H transmissions using around 100 of the Siemens prototypes in a major German city later this year, whilst O2 is planning to work with NTL and Nokia for a six-month trial of DVB-H amongst 250 customers in Oxford.
Although details of the O2 trials were still at the planning stages at press time, the game plan is to use a single-frequency network with nine base stations covering a 120 square kilometres area around Oxford.

O2 has yet to confirm which handset vendor it will be using for its trials, although it should be noted that Siemens is not alone in developing DVB-H-compliant mobiles.

Samsung, for example, also showed off its first DVB-H handset at CeBIT. The handset, which supports both CDMA and GSM networks, making it suitable for global usage, does not feature any recording facilities.

Critics of DVB-H point out that movie trailer interaction by customers is nothing new, but the key feature of DVB-H is that it enables easy viewing of TV transmissions - and interaction, if appropriate – in real time, just like on a regular TV.

The 3.5G alternative

But DVB-H isn't the only TV-on-a-mobile technology on the block, as users of 3G handsets on Hutchison 3G, Vodafone and Mobilkom Austria networks will be aware.

The alternative technology to DVB-H is known generically as video streaming, which has the advantage that it can operate across multiple mobile standards, ranging from 2.5G (GPRS) right through to 3.5G.

3G video streaming is already quite popular in several countries, but is not really suitable for real-time TV transmissions because of the relatively low (150 to 220 kilobits per second - Kbps) speeds currently available on 3G networks.

Plans currently call for most 3G networks in Europe and Asia to support mobile data speeds of 384 Kbps within the next few years, but even this speed is only just enough to support a VHS tape quality TV transmission with minimal bandwidth headroom.

For faster transmissions we have to turn to 3.5G technology, better known in some circles as HSDPA (High Speed Downlink Packet Access), which is now entering trials on both sides of the Atlantic.

The development of HSDPA is thanks to a number of software modifications for 3G networks that Lucent, Motorola and Nortel have developed in concert with carriers such as Cingular in the US and O2 in Europe.

By tweaking the way in which data is transmitted from the base station to the mobile, Lucent and Nortel claim that data transmissions can be speeded up from the current 384 Kbps maximum with 3G to around 3.6 megabits per second (Mbps) on 3.5G.

Eventually, the two vendors claim, it should be possible to push data download speeds up to a theoretical maximum of 14.4 Mbps on the downlink and 5.8 Mbps on the uplink.

In trials, Cingular and O2 say they have observed download speeds of, respectively, 2.0 and 2.9 Mbps, on their test 3.5G services.
Even under a full 3G cell site loading, data speeds in excess of 1 Mbps are expected - more than enough room for point-to-point mobile narrowcasts of various channels.

Although HSDPA is a technical compromise compared to DVB-H's shiny new technology, HSDPA has the key advantage that it uses existing 3G network infrastructure with software, rather than hardware, modifications.

Thanks to this fact, it looks likely that 3.5G technology could reach the market more quickly than DVB-H.

In the US, Lucent and Cingular remain coy on 3.5G timescales. Europe's O2 is more ebullient. It expects to introduce commercial HSDPA on its 3G networks some time during 2007.

Next year's World Cup could force their hands on timescales, so our best guess here at AlanDick is that 3.5G-based TV-on-a-mobile transmissions could be soft launched as early as the spring of next year, but don't expect too many handsets to be available.
- Main copy ends – 1231 words
- Optional box-outs follow

Boxout 1 - national TV-on-a-mobile systems also in development
Even though the European and US carriers are developing DVB-H and 3.5G TV-to-mobile technology apace, it's worth noting that other systems are also in development.
Japan and South Korea have been working on their own systems for the past few years.
The Japanese system - known as ISDB-T (Integrated Services Digital Broadcasting - Terrestrial) is currently at the field test stage.
The South Korean system - known as DMB (Digital Media Broadcasting) - is expected to enter field testing later this year and is already seen in handsets from LG and Samsung.
These Asian developments could confuse the marketplace as, even though Japan and South Korea are not on the GSM map, they each have two 3G networks already operational.
Just to make life even more interesting, Qualcomm has developed yet another TV-to-mobile system based around the ASTC (Advanced Television Systems Committee) standard.
The bad news with Qualcomm's multicasting system, known as MediaFLO (Forward Link Only), is that it is proprietary and designed specifically for the 700-megahertz waveband.
The danger with these country-specific (and incompatible) services is that the cellular industry could end up with a similar range of disparate systems seen with 2G and non-GSM networks.

Boxout 2 - Crown Castle plans commercial DVB-H deployment in US
In the US, Crown Castle is well on its way to rolling out a commercial DVB-H network operating at 10 Mbps, following trials of the technology in concert with Nokia in Pittsburgh, Pennsylvania.
Crown Castle has more than 10,000 of its cellular towers and hold a national US spectrum licence, so the logistics involved with upgrading its network to support DVB-H are not that great.
Samsung has already announced plans to work with Crown Castle on its US network, with the Korea company supplying handsets for use on the fledgling Mobile Media service.
According to Samsung, its handsets for use on the Mobile Media service will have two-inch QVGA colour screens capable of showing 226,000 colours at rates of up to 30 frames per second.
Most interestingly of all, Samsung says that handsets will receive DVB-H transmissions at data speeds of around 300 kilobits per second.
Although this data speed is lower than many experts have predicted, it's around the same speed as used on sub-channels on digital terrestrial and satellite TV transmissions.
On a regular TV, these transmissions are around the same quality as a regular VHS tape, but for a mobile phone with a small screen, the picture quality is more than sufficient.

Boxout 3 – what frequencies will DVB-H operate at?
One of DVB-H’s advantages is that it can be used across a wide range of frequencies.
In the US, Crown Castle has been using the L-band (1.5 gigahertz) for its Pittsburgh trials and plans to use the same frequency on its planned national network.
In Europe, L-band availability is limited, as several frequencies in the waveband have been assigned to Digital Audio Broadcast radio transmissions.
European broadcasters and carriers tend to favour Band III (VHF), Band IV or Band V, with Band IV (470 to 650 megahertz) being the favourite owing to propagation and interference levels.
The critical factor in getting DVB-H rolled out commercially could be the European Commission, which will have to decide on which frequencies the DVB-H broadcasters can use.
This could pose a problem, as different countries within the EU member states have allocated different frequencies in L-band and Bands III, Iv and V.
Achieving consensus on which frequencies to use for DVB-H could take time – time that the networks and broadcasters don’t want to waste, owing to potential lost revenue and the danger that other TV-on-a-mobile standards could gain a foothold.

Boxout 4 - why is AlanDick interested in these technologies?
With more than two decades of experience in servicing the needs of the broadcast and cellular infrastructure industries, AlanDick has a history of being a one-stop shop for broadcasters and cellular networks worldwide.

Whether networks opt for 3.5G or DVB-H - or as yet undeveloped – technologies - AlanDick will be able to meet the installation and deployment needs of the broadcasters and cellular carriers as they roll out their new services.

Because of the costs involved, we expect many carriers to co-locate their DVB-H transmission systems with their existing cellular networks.

Whichever standard asserts itself as the medium of choice for TV-on-a-mobile transmissions, AlanDick's technologies and skill sets will help ensure that your favourite programs reach your mobile phone as efficiently as possible.

This Weeks 3G News By Photos
This Weeks 3G News
Site Map
Phones Reviews Phone Store 3G Forum 3G UK Pro Zone 3G Newsletter 4G 4G Press Releases 3G News By Photos This Weeks 3G News Search Rewind Tones Gadgets US Zone Euro Zone ASIA Zone 3 Page 3
Past 3G Features
Dec 2005 Nov 2005 3G Oct 2005 Sept 2005 Aug 2005 July 2005 June 2005 May 2005 April 2005 March 2005 Feb 2005 Jan 2005
Press Releases Dec 2005 Nov 2005 Oct 2005 Sept 2005 Aug 2005 July 2005 June 2005 May 2005 April 2005 March 2005 Feb 2005 Jan 2005
About / What Is 3G
About Us Intro To 3G
Advertising 3G Technology
This Weeks 3G News By Photos
This Weeks 3G News