Bert, DAB+ was based on or incorporates some of the work by DRM. I am not sure what it has adopted, beside the L-Band, and codec, modulation(?) from what I remember from the annual IBC release I received from Digital Radio Mondiale.
Currently broadcasters are being forced onto DAB+.Traditional issues hindering DAB have been coverage and audio quality, all lower with DAB than FM. I very clearly remember a demo by NOB at IBC, 'put the headphones on and listen when the quality drops to unacceptable'. 192 Kbit/s was still very acceptable, but below that quality dropped off steeply, 128 sounded horrible. This must have been 1995/6? Guess what overhere they went with 64 Kbit/s the so-called (bandwidth?)equivalent of an FM Radio channel. Given the standard being set in stone, quality advances had been (next to) none.
Add that choice was very limited, where on FM (and AM) commercial radio had been introduced not too long before. The government being forced into the release of frequencies and the public broadcasters having to reduce its coverage. The commercial broadcaster have recently been forced to agree to DAB+ deployment to get an extension to their FM licences.
Finland disbanded DAB for DVB-T(2), the UK has seen initial promotion on a grand scale from the BBC, but it just took too long for even the BBC to hang on all the time. UK also has had some coverage issues, but had stations on DAB that were not always on FM, to differientiate Digital from Analog.
d. Quoting "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>:
Ron Economos posted:The link should be:http://tech.ebu.ch/docs/tech-i/ebu_tech-i_018.pdfThanks, Ron. Very interesting articles. Why digital radio is taking so long is a really good question, ESPECIALLY in the US, where we actually have a clever system. No impact on spectrum, most radio broadcasters are already transmitting HD Radio (in our market, at least), so the only impact is to get receivers out there. (My answer is that it's all about money. E.g., GM would be much happier to sell Sirius/XM subscriptions to new car buyers, than to have them tune in to HD Radio for the one-time, slight additional cost of the radio.)IMO, Europe should also go to something like HD Radio (aka Ibiquity's scheme), or the German DRM system, in preference to DAB. Why? Because what more effective use can the 550-1620 KHz and 88-108 MHz frequency bands be put to? HD Radio is set up to operate in hybrid mode during the transition period, without taking up other frequency bands, so it seems an easy approach. DRM doesn't have a true hybrid mode, but it can operate in a similar way anyway, in AM and FM bands. DRM can use previous guard bands or spare channels, effectively duplicating what HD Radio does. DAB, on the other hand, needs high UHF and L Band, so switching off FM and AM to go to DAB means leaving these AM and FM bands free of signals. Bands **no one** is aching to use.As far as I've been able to decipher, the biggest technical concern with HD Radio is that it slightly degrades the FM signal? And it can't be used at night on the AM band, until analog AM goes off the air. Assuming these were real issues, and not just an excuses, if you're trying to end FM and AM transmissions, do these concerns really matter?Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways:- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.
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