| All DAB receivers will be obsolete in a few years' time30th November 2006 The DAB system has recently adopted the new AAC+ audio codec, and existing stations that use the old MP2 format will probably be switched off completely in the UK in around 7-8 years' time. More to the point, however, DAB radios being sold in the shops today will not be able to receive any of the many new stations that will launch using the new AAC+ format in the coming years; some of which will probably launch as soon as 3 years from now. However, DAB receivers that will support the new AAC+ codec will be available from summer/autumn 2007, so if you want to buy a DAB receiver that will be able to receive these new stations you would be best off waiting until then.
Frontier-Silicon's new DAB/DAB+ modules
The new receivers that will be available will use new DAB receiver modules produced by Frontier-Silicon, which produces the modules for 80% of all DAB receivers. Frontier-Silicon has already announced two new modules based on its new Kino2 DAB processor chip (the Venice 5 module, which is meant for portable radios and hi-fi system products, and the Capri module, which is aimed at MP3 players and similar portable products) and Frontier-Silicon has told me that its new modules will be fully software upgradeable to support the new DAB+ standard via USB. So receivers containing the new modules from manufacturers that put USB sockets on the back of the receivers — such as those from the market leaders Pure Digital — will be able to receive the new stations that use AAC+ once a software upgrade has been made available for them. Then by autumn/winter 2007, Frontier-Silicon's new modules will support AAC+ as standard. As well as being future-proof, Frontier-Silicon says that their new Venice 5 module will consume seven-times less power than current DAB modules do, which equates to an approximate tripling of the battery-life compared to current DAB portable radios. The short battery-life of current DAB portable radios has been another of DAB's problems, so a three-fold increase is a huge leap forward. The reduction in power consumption has been achieved by moving external memory onto the chip itself in order to eliminate power-hungry bus transfers between the processor and external memory. The new modules will also be cheaper and smaller than previous DAB modules, and Frontier-Silicon has said that it expects the receiver manufacturers that use its modules to quickly migrate their products to using the new modules — the fact that the new modules are cheaper would be enough motivation alone for receiver manufacturers to switch to using them, but with them offering a tripling of the battery-life then it's hard to imagine any manufacturers that use Frontier-Silicon modules wouldn't switch. Indeed, I wouldn't be surprised if some receiver manufacturers that currently use Radioscape modules switch to using Frontier-Silicon's because of this huge improvement in battery-life, as Radioscape won't be able to come close to matching the power consumption, because Radioscape uses off-the-shelf Texas Instruments DSP chips to run its software, so it cannot move external memory onto the chip itself. Furthermore, because the new Venice 5 module is 50% smaller than previous modules, existing receivers will only require slight internal modifications to incorporate the new module, and Frontier-Silicon has produced reference designs to allow this to happen. The second biggest DAB module producer is Radioscape, and it also plans to bring out a new module to support DAB+ next year, in time for when countries plan to start using the new DAB+ standard — Switzerland is in the process of advertising slots on a new DAB multiplex for the German-speaking area of the country; New Zealand plans to launch using DAB+ next year; Australia has committed to using DAB+; and France wants to launch digital radio as soon as possible using AAC+ on DAB+ or DMB, although the decision about which system will be used hasn't been taken yet. The overall picture is that it is expected that the vast majority of DAB receivers being sold in the UK will support the new DAB+ standard within a short period of time — either via a software upgrade or natively supporting it.
The road to AAC+ on DAB in the UK
The decline of DAB and the rise of DAB+
How quickly it will be before AAC+ is used on DAB is dependent on the proportion of DAB receivers in the UK market that support the new DAB standard. The good news is that DAB is still in the relatively early stages of growth, and sales are forecast to really take off over the next few years. The graph below uses figures from the DRDB's (Digital Radio Development Bureau) Five-Year Sales Forecast, and I've projected sales a further few years into the future. The DRDB forecast that there will be 4.6m DAB receivers sold by the end of this year; 13m by the end of 2008, and 20m by the end of 2009. The only assumption I've used for sales following 2009 are that the rate of acceleration of sales is the same after 2009 as it is before. The acceleration in DAB sales is due to the combination of lower receiver prices and more products being available for areas where DAB hasn't sold well to date, such as micro systems, car stereos and MP3 players.
If you think these cumulative sales figures look high, remember that the broadcasters would like to switch off FM as soon as possible, and there are estimated to be around 120m FM receivers of one sort or another (such as portable radios, hi-fi systems, car stereos, portable CD stereos, radio alarm clocks etc.), so if they haven't managed to reach 70m cumulative sales by 2014 then you have to ask yourself when they will be able to switch off FM. Also, Ofcom has recently suggested that it thinks that 90% of all radio listening will be via digital in 10 years' time, so the graph above would seem to be in keeping with Ofcom's forecast. With regards to the decline in the number of legacy DAB receivers, I actually think I've been relatively conservative in the rate of decline. For example, according to Ofcom, the number of legacy OnDigital/ITV Digital set-top boxes in the UK market in October 2002 when Freeview launched stood at over 1m, but by September 2005 there were only estimated to be 300,000 such receivers left in-use — a drop of 70% in just 3 years! These receivers were still capable of receiving the TV channels on Freeview, and the rapid decline was simply due to newer receivers functioning better (e.g. faster channel change) than the old ones did and offering features that the old receivers didn't support, such as the electronic programme guide (EPG) and better support for digital teletext. On DAB, the prospect for better functionality and more advanced features being provided by newer receivers in comparison with legacy receivers is arguably far more attractive than with the case of Freeview receivers. The following is a list of improved functionality and features that will become much more commonplace that either aren't provided at all yet or are only provided on the higher-end DAB receivers:
And the above list doesn't even include the new stations that will launch using AAC+ nor the addition of the MPEG Surround format that has been adopted for the new DAB+ system...
New stations using AAC+
The main thing the graph above shows is that 3-4 years from now the vast majority of DAB receivers will support the new DAB+ standard, so the business case for launching new commercial radio stations — that wouldn't be able to launch using the old MP2 format — using the AAC+ format will become overwhelming. And with Ofcom being, in their own words, "biased towards non-intervention", they won't stand in the way of the commercial radio groups launching new stations, and I have no doubt that we will see new commercial stations launching using AAC+ within this timeframe. To see why this is so likely to happen, you just have to look at how much the commercial radio groups want to launch new stations. For example, the ex-head of digital radio at Emap, which is the second-biggest commercial radio group, once told me that Emap wanted the minimum bit rate for stereo stations to be reduced to 96 kbps! 96 kbps MP2 would provide ridiculously low audio quality, and the only reason he wanted Ofcom to allow this was so that they could launch new stations. And GCap/Digital One have also been lobbying Ofcom to allow them to use 112 kbps instead of the usual 128 kbps for stereo stations, and yet you would have to reduce 7 stations from 128 kbps to 112 kbps in order to allow just one measly 112 kbps station to launch in the freed-up space! Basically, once it becomes financially attractive to launch new stations using AAC+, and once sufficient time has past to allow them to do so without consumers kicking up a fuss, they will launch new stations. And it is hardly apocalyptic if they do launch new stations using AAC+, because legacy receivers will continue to work merrily away as if nothing had happened. Yet if you believed the doom-mongers, if stations were launched using AAC+ there would be mass public revolts, probably leading to the decapitation of Terry Wogan. My simple response to this is that the vast majority of people with legacy receivers will simply be blissfully unaware that they're missing out on anything whatsoever, because their legacy receivers won't explode when the first AAC+ stations started transmitting. And using past broadcaster performance as a good guide to the future: if they're willing to broadcast 98% of stereo stations at low audio quality, as they do at the moment, and they're more than happy to transmit a large number of music stations in mono, why on earth do people think that they'll become all conscientious all of a sudden? They won't, it's as simple as that. And the commercial radio industry is struggling financially at the moment with 16 - 24 year olds abandoning radio in droves and advertising money shifting towards the Internet, and it's only likely to get worse in future. There is also the future threat posed by the Ondas Media subscription satellite radio service that is planned to launch by 2009/10, and as this subscription service will offer a wide range of stations, and as it is subscription-based they will likely cover niche genres that advertising-funded stations don't cover (at least at the moment on the inefficient old DAB system), the broadcasters will want to make DAB as attractive to consumers as possible in order to minimise the number of people deciding to subscribe to the new satellite service, because I dare say that most of those that do subscribe will stop listening to commercial radio for good.
Phased introduction of AAC+ stations
As I've already mentioned, the legacy MP2 services will not be switched off for quite a few years yet, but that doesn't stop them from introducing new stations using AAC+.
New stations in unused capacity
Firstly, with only a couple of exceptions, the only local DAB multiplexes that are full at the moment are those that cover the biggest cities in the UK. And there will also be new multiplexes launching as a result of the UK obtaining additional spectrum for DAB from the Regional Radio Conference in the summer:
So there is already scope to launch AAC+ stations using capacity that is either currently unused or on multiplexes that will launch in future.
Reducing the quality of exiting MP2 stations
But even on multiplexes that are full, it is possible to launch stations using AAC+ without withdrawing any stations by simply reducing the bit rates of the existing stations. I would expect this to happen as follows:
1. Reducing 128 kbps stereo stations to 112 kbps
By reducing the bit rates of stereo stations from 128 kbps to 112 kbps and mono stations from 64 kbps to 56 kbps. This would allow the following number of new AAC+ stations to launch (assuming the whole multiplex is used for radio stations):
This alone would allow an increase of around 44% in the number of stations on DAB — but this is nothing compared to what will follow. Ofcom has already agreed to allow the commercial radio groups to reduce their bit rates from 128 kbps to 112 kbps, and yet strangely no stations have yet been reduced to 112 kbps — as they haven't reduced the bit rates when they're allowed to and they've been lobbying for this to happen, are they planning ahead for the introduction of AAC+, or am I giving them too much credit? As already mentioned, the benefit is very small if MP2 is used, because 7 stations would have to have their bit rates reduced to allow one new 112 kbps station to launch, but because AAC+ is vastly more efficient than MP2 then 4 stations will be able to launch if the bit rates are reduced, and the audio quality of these new stations at 48 kbps would be a lot better than the 128 kbps MP2 used at present.
2. Reducing 112 kbps stereo stations to 56 kbps mono
When we reach the right-hand side of the graph above — about 2011 or 2012 onwards — the vast majority of all receivers will support AAC+, and I would then expect them to reduce their stereo stations to mono in order to allow the following number of new stations to transmit:
They might do this early on, because there are already plenty of mono music stations transmitting on DAB, so if they find it acceptable now then when only a small minority of receivers are affected they won't think twice about doing it. And one of the advantages of the vast majority of DAB receivers sold-to-date being portable radios is the fact that owners of such devices wouldn't even notice that stations have been reduced to mono anyway.
3. Switching off all of the MP2 services
Once the UK reaches the position shown on the far-right-hand side of the graph above where the legacy DAB receivers only account for about 2% of the total number of receivers, it then becomes feasible to switch off the MP2 services altogether. People shouldn't complain, because assuming this happens in 2014, as per the graph, they would have had at least 7 years of use from their legacy DAB receiver and a replacement DAB+ receiver will cost peanuts and provide far better funtionality. This will allow the following number of stations to launch in the freed-up capacity:
The BBC DAB multiplex
The above description is only about the commercial radio stations, and the BBC won't be allowed to launch any new stations, or if they do launch any it will only be 1 or 2 at most. Also, the BBC has also already said in its recent submissions to public consultations that it does want to improve the audio quality of its stations on DAB, and as the following table shows, the BBC could provide very good audio quality on all of its radio stations and provide MPEG Surround on all of the stations that would likely use it, and there would be a third of the multiplex left over!
Overall, if you buy a new DAB radio now, it won't stop working for many years, but you will miss out on plenty of future stations and better audio quality.
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