DAB+ , DMB & DRM

www.vk4ajj.com

Now for a little bit more unfamiliar sounding systems. Ones you might not have heard of. They are not new systems  they’ve all be around for a couple of years already. So firstly let’s start off by explaining why DAB+, DMB or DRM being advertised or even mentioned anywhere. BBC is biased towards DAB and will defend it till its undeniable demise. In the meantime keeping hush about any other system out there. They stupidly invested too much on DAB. And they are the ones who are supposed to be unbiased towards any platform be it satellite, freeview or internet radio – yet they advertise for DAB as if it was the best thing since the wheel. They’ve spent over 100 million advertising for DAB radios. None on freeview or internet radio. Yet they’ve only sold a tad over 6 million receivers. And year on year sales are falling. If only there was a system that could surpass the quality, be of similar built or compatible with the old analogue systems and… ahaaa – simple Googling session comes up with many interesting solutions: DAB+, DMB, and DRM. So rant over, let’s have a look at why they are a better investment of your money.

DAB+

www.radio-now.co.uk

In 2006 WorldDMB announced a major backwardly compatible system and in February 2007 an updated version of DAB was released  DAB+. It is about 2-3 times as efficient as DAB since moving over to AAC+ audio codec allowing up to three times the programs per channel compared to DAB. Finally we have a system that is using a format which was designed for digital broadcasting.

They have also adopted better error correction in the form of Reed-Solomon coding (which could have already been used on the first DAB version as it’s been used on CDs ever since 1987) and MPEG Surround. The DAB+ broadcasts have already been launched in some parts of the World. For example – Switzerland, Malta, Italy, Australia, Hungary, Germany, New Zealand, to name a few and there are several other countries such as China, India, The Netherlands in the verge of launching their digital revolution. You can find out if it is available in your country by clicking the link here.

DMB

gadgetzone.nl

Digital Media Broadcasting is a South Korean technology used in digital radio transmissions to send multimedia to mobile phones. A lot of people know it for a more friendly term – mobile TV (however the use of this term is misleading as there are other platforms for that such as DVB-H). It was developed as next generation digital technology to replace FM radios. DMB technology is similar to DAB but in addition to audio, it is also possible to provide additional video and multimedia information. It can operate via satellite (S-DMB) or terrestrial (T-DMB). In 2005 South Korea started broadcasting in both of those systems. Receivers are integrated into mobile phones, sat-navs, laptops, and even digital cameras. According to WorldDMB it is the most successful mobile TV standard with over 8 million devices sold at the moment.

DRM

radiomagonline.com

Digital Radio Mondiale is a set of technologies designed to work over the current AM band. It can fit more channels with better quality into the same bandwidth. It can deliver FM quality signals on Frequencies below 30 MHz meaning that their network coverage is bigger. It has been developed so that the broadcasters can use the same antennas  avoiding costly upgrades. The system is also robust  meaning less interference and fading. As a digital medium it’s also possible to broadcast data or datacast if you will. The only major difference between other systems and this is that DRM can operate in a hybrid mode called Single Channel Simulcast, simulcasting digital and analogue signals at the same time. In March 2005 DRM consortium voted to extend the system up to 108 VHF. The multiplex and audio codecs will be the same – just at higher frequencies. They’ve also decided to name this DRM+. It is currently being tested all over Europe.

Multichannel possibilities

DAB Surround brings multi-channel sound to DAB services at stereo bit-rates without the need to simulcast stereo and multi-channel programs. It combines the new DAB+ HE-AAC v2 audio codec (or, alternatively, the existing DAB MPEG Layer 2 audio codec) with MPEG Surround. MPEG Surround is the surround extension for perceptual audio codecs, combining backwards compatibility with high-quality surround sound at stereo bit-rates. MPEG Surround is part of the WorldDMB specification. When combined, DAB+ and DAB Surround enable the smooth, mono / stereo compatible and cost-efficient introduction of multi-channel sound to digital radio at low bit-rates and high audio quality. DAB broadcasters can provide 5.1 channel surround sound at a total audio sub-channel bit-rate of only 96 Kbit/s or less. This data-rate includes the stereo signal.

It is all possible dear friends. When its going to actually happen is another question. Looking at the wonderful digital revolution we are having in the UK… Even Ofcom and BBC cant put this off for long. If they do – they are shooting themselves in the leg. It could be a very costly mistake to make. DAB as it is now – will probably be remembered as digital radios betamax – a total and utter failure. In the meantime – Don’t buy a DAB radio. If you like a traditional radio setup get a DAB+, DMB or DRM instead. If you are feeling adventurous then walk with us to the wonderful world of internet radio – connect your speakers to your audio output and blast away.