High Definition Radio is Here 389
nfranzen submits this story/advertisement: "Yesterday, I had the opportunity to buy the first High Definition (HD) Radio in the United States. HD Radio, invented by iBiquity Digital, adds a digital channel to the sidebands of an existing analog FM signal. The technology is still pretty new, but I can tell you first-hand that listening to my favorite local FM station in HD sounds just like I am listening to a CD. Well, except for the commercials (grin). Here are some links to local TV news coverage and a news release for more info. HD receivers will hit the open market following the Consumer Electronics Show next week in Vegas." We had an old story about the FCC approving these digital broadcasts in the FM radio bands.
Re:Satellite radio (Score:2, Informative)
Take a long trip through the american southwest or into the bible belt and see what you think of broadcast. In the Mojave I only got AM stations at night, thanks to the lowered ionosphere. It can also be pretty tough anywhere finding a station you consistently like listening to. With the 4 presets I have for sat. I'm pretty happy and can listen to them in the middle of Death Valley if I want (which I have done.)
Re:Solution looking for a problem (Score:4, Informative)
There is no local radio anymore. It's all Clear Channel and...somebody else.
Re: DAB (Score:3, Informative)
I recently bought a DAB radio alarm, and I find the quality is pretty good. Admittedly, I can't tell if it is better or worse than FM through the speaker on the radio itself (although that rather reinforces what others have said on this story - that FM quality is not the limiting factor in most listening environments). Sometime, I mean to plug it into my HiFi and see if I can hear any difference.
Re:DRM??? (Score:4, Informative)
How about high-definition telephony? (Score:4, Informative)
Re:spoilt (Score:4, Informative)
Re:Solution looking for a problem (Score:4, Informative)
The problem is not the FM signal technology, but your cheap-o FM tuner, and likely your crappy FM broadcaster. If you ever get a chance to listen to a good FM tuner (which these days pretty much means one made by Magnum Dynalab) with a decent antenna, you'd be amazed at how good FM is capable of sounding.
None of which helps in the car, of course...but I'd spring for a Sirius system before an HD FM system, given that I still could only listen to the same crap local ClearChannel stations.
Re:What's the catch? (Score:5, Informative)
Keep in mind that digital signalling techniques weren't really invented at all until the 1940s. And that AM was deployed before than, and FM either before that or not much after.
Is it inconceivable to believe a brand new field has seen startingly gains in efficiency in 60 years time? Look at how much modems improved (56kps over the same line that once only supported 150bps...nearly a 400 times gain).
There is no catch. Telecommunications technology has just improved a hell of a lot in the last 100 years.
This is the reason why cell phone provides are so antsy to relaim all those 6 MHz wide UHF allocations....you can use that bandwidth so much more effectively with modern techniques, instead of throwing raw, uncompressed analog data out there.
Also witness the huge number of digital channels cable providers have packed into coax, despite the continued presence of regular TV stations, AND internet connections.
And this is the part where everyone should stop whining about taxes and having to give money to their local learning institution.
analog vs. digital (Score:5, Informative)
With AMPS, as the signal gets weaker, the audio noise floor comes up, and you get wideband static on the signal. Wideband static is fairly benign, in that humans aren't as offended by it (since it sounds like the surf). The user of the phone knows he is getting out of range well before the call drops, and so usually can terminate the call gracefully.
With digital, you get no real degradation of the signal so long as the channel bit error rate is less than the channel's error recovery capability. But when the BER gets above that threshold, then the quality drops dramatically. Moreover, the loss of quality is expressed as garbled vocoder output (I've always described it as "watery" - it sounds like you have water in your ears), or as complete failures of the vocoder (dropouts). Those are VERY offensive to the ear.
Also, the difference between a signal level that gives you a fully correctable BER and a signal level that gives you a BER bad enough the phone drops is almost nil - so just changing position can drop the call without warning.
Personally, if the phone makers would tie the received signal strength indicator (RSSI) into a variable noise generator, so that as the RSSI fell you started to get static, I think most people wouldn't bitch so badly about dropped calls.
There is also the problem that the usual vocoders for phone use are compressing the crap out of the signal - taking a 64 kb/second audio stream down to less than 4kb/sec. VSELP, IMBE and AMBE all do OK when fed voice in isolation, but put in any background noise and they get "confused" - they start making poor choices about the vectors they encode, and what comes out the other end is pretty rocky.
I had great fun feeding the first few seconds of Kansas's "Carry On Wayward Son" into an APCO-25 IMBE vocoder. While there is nothing but voice there, it is a chorus, and the poor vocoder just couldn't figure out what was going on.
Re:High Definition? (Score:2, Informative)
Re:Forget IBOC - The rest of the world has DAB (Score:2, Informative)
Another article on ISDB-T [nhk.or.jp].
Re:Is this the same as the BBC offering? (Score:4, Informative)
The US system is completely incompatible, of course. In 10 years when I drive my car across the USA/Canada border, my radio will stop working. Nice.
Re:HD Radio vs. DAB? (Score:1, Informative)
Re:HD Radio vs. DAB? (Score:1, Informative)
You should be able to get cheaper than that though - import one from the UK!
Re:Is this the same as the BBC offering? (Score:2, Informative)
Anyone know anything about this?
Re:Is this the same as the BBC offering? (Score:3, Informative)
Sorry, that's rubbish - but I can see whey you're getting confused. Rather than get together and agree on an international standard, it seems we're being treated to a country-by-country bodge job.
However most of the systems being implemented at the moment use some variant of the UK-led DAB (Digital Audio Broadcasting) system, the main difference being what frequency range you broadcast on.
That said most DAB radios now being sold in the UK are multi-frequency and so can be used in other imlementing the system (France in particular have a pilot system in place at the moment). Oh, and Canada :-)
DAB is great - apart from the fact that it uses MP2 as the codec. Coupled with the fact that most UK stations have picked a woeful bitrate, the result is far from hi-fi quality; actually a step back from FM quality IMHO (especially if you have a high end FM radio that can get rid of multipath distorsion).
Look here [radio-now.co.uk] for more info on DAB.
On the plus side, you do have lots of stations to choose from on Digital, including the excellent BBC7 on which the Beeb have been dusting off some of their best radio comedy, drama and documentary series.
Re:Is this the same as the BBC offering? (Score:1, Informative)
it has to do with what band was free in each country (or rather what bands could be wrangled from the hands of the military authorities in time for the launch, the bands used being something that was originally given to Nato for future use), in the UK there was not sufficient time so they lauched on the lower band and with the option of also rolling out the higher one later if political and commercial issues are sorted out, and since DAB was a massive hit in 2002/2003 I suspect that this will happen, they are already running out of bandwith.
I Germany the higher band was unceremoniously pried from the military authorites and thus they have a much greater range of stations and higher bitrates
In the USA the USARMY refused to let go of the bands despite not apeearing to be using it at the moment (US radio stations and the FCC techs wanted to use the Eureka system). the "politicos" however wanted a US designed system (despite the Eureka system being available to them licence free) so you have HD
AM stereo all over again
Nice one FCC
In true /. fashion ... (Score:3, Informative)
DAB is 10 years old already according to this history page [planet.nl].
DAB (Score:1, Informative)
(ripped from worlddab.org's faq)
DAB stands for Digital Audio Broadcasting. DAB is a digital radio system, which was developed by the Eureka 147 Project. It offers near CD-quality sound, more stations, additional radio and data services and therefore wider choice of programs, the ease of tuning and interference-free reception for the listener, plus the information potential of data, graphics and text. For the broadcaster, DAB provides a means of reaching listeners with sound quality on an equal footing with the CD player, and the ability to offer extra, potentially revenue-creating, services. Transmission will also be cheaper. For other areas of industry, there will be a new market for receivers and transmission equipment.
Why does the US always have to have its own format? See http://www.worlddab.org/cstatus.aspx and select "USA" from the drop down list.
For the lazy:
"(23/01/2003) While the Eureka 147 system has emerged as clearly superior in laboratory and field tests carried out by CEMA (Consumer and Electronics Manufacturers Association), the National Association of Broadcasters opposes the adoption of Eureka 147 in the USA. This opposition is based on lack of new spectrum; dislike of sharing transmitters in the multiplex; and concerns that DAB would introduce new competition. The USA have now developed a more limited in-band solution (originally named IBOC, In-band on-channel, but now called HD radio), utilising existing FM transmitters."
Sigh. Oh well, I'm glad I live in Canada!
$500 receiver? (Score:2, Informative)
Kenwood has a HD radio module that you can add to an existing car receiver. $500! What a bargain!
Kenwood KTC-HR100 [kenwoodusa.com]