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Grex > Radio > #2: Digital radio broadcasting |  |
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keesan
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Digital radio broadcasting
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Feb 14 01:27 UTC 1998 |
I have heard rumors of digital radio broadcasting, on the same theory as CDs,
which would allow far more stations and better reception. And that for a
while stations will be required to also broadcast AM and/or FM. Is this in
the near future, are their receivers available yet, has it been done in other
countries? I ran across it in a complaint that this would subject us to more
potentially harmful EMF radiation (can't imagine how, unless you live very
near the transmitter). Anybody know more about the theory or practice?
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| 210 responses total. |
rcurl
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response 1 of 210:
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Feb 14 05:22 UTC 1998 |
I have not looked into the technology as currently proposed, but it *could*
work the same way the web works, except via radio rather than via wires
and fiber optics. In fact, I think the web is already using satellites,
and you can now have web TV with sound (though limited by the speed of
your link to the system). OK - someone - how will it really be done first?
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keesan
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response 2 of 210:
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Feb 14 15:51 UTC 1998 |
Are you referring to the same system for the web as is being used for packet
ham radio? What is web TV? Is that digital TV broadcast?
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keesan
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response 3 of 210:
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Feb 14 16:41 UTC 1998 |
Jim asks, remember quadruphonic and AM stereo. He thinks AM stereo is still
broadcast but was quadruphonic broadcast, or is it just the same as 'surround
sound'. We have an old receiver that does stereo FM and quadruphonic for
phono imput and for the builtin 8-track. ANybody interested in it? (It needs
the FM tuner fixed, the rest works now.) Some formats flop, but FM stereo
and color TV are still around. Any predictions on digital radio (or TV)?
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rcurl
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response 4 of 210:
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Feb 14 20:27 UTC 1998 |
Packet ham radio works can be done with the same protocol used by the web -
TCP/IP. Web TV is motion pictures with sound transmitted in TCP/IP protocol
for viewing with a computer. One could have digital TV with just a serial
"terminal" protocol, but each station would require a separate band allocation
as now. That would be the simplest. As I said, I do not know which technology
is being proposed for first general digital TV broadcast.
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keesan
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response 5 of 210:
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Feb 14 21:28 UTC 1998 |
Please explain in nontechnical English 'TCP/IP protocol' and 'serial
"terminal" protocol. I am pretty computer-ignorant. Is Web TV real-time or
do you download an entire 'broadcast' onto a large hard disk? What sort of
hardware/receiver equipment is needed for digital reception not over the Web?
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rcurl
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response 6 of 210:
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Feb 15 06:38 UTC 1998 |
TCP/IP is Terminal Control Protocol / Internet Protocol. It is the one
where digital data are subdivided into packetsl (1024 bits?) that also
carry codes for order, origin and distination. These can be sent all
mixed up with packets from other messages from other senders, and detected
and put back into order and decoded by the recipient. This permits a large
number of users to transmit simultaneously in the same band. This is what
the internet/web uses.
Terminal protocol is a serial transmission of the message starting at
the beginning and running until the end. The message might also be
divided into successive packets (to check transmission while it is occurring)
but the packets are sent and received in the order in the message. If this
is done it still causes delays since the next packet will not be sent until
the previous one has been acknowledged.
Web TV is about as "real-time" as ordinary TV - pictures are sent in frames
and presented consecutively at a rapid rate. Web TV is a digital signal,
however, while common TV is analog. Your computer needs a video board with
the capabilities for fast decoding of the digital video signal.
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keesan
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response 7 of 210:
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Feb 15 19:16 UTC 1998 |
Could this same system be used just for radio transmission? Is it being done
anywhere yet? Does Web TV also have an audio component?
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terry
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response 8 of 210:
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Feb 16 03:55 UTC 1998 |
WebTV supports Realaudio.
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keesan
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response 9 of 210:
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Feb 16 04:57 UTC 1998 |
What is that? Can you get classical music with it? If so, with or without
commercials, is it different from the local broadcast stations? Is it a way
to get distant stations, or something like what the cable TV company offers,
which is a randomized assortment of taped music with no commentary and no
schedule (it really is random)? I would love to be able to get other stations
from around the country, espcially after losing WUOM and WQRS, and especially
at hours when there is only news, and on weekends. Does WebTV cost much?
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keesan
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response 10 of 210:
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Feb 20 00:35 UTC 1998 |
I tried the website for realaudio, it was mostly graphics, which I can't read,
but seems to be something you add to website advertising. For digital radio
broadcasting I found www.drb.crc.doc.ca/, about Canadian research and the fact
that four cities will soon be broadcasting digitally at about 1.5 GHz, and
that most of the equipment is being made and used in Europe, and the receivers
will be sold in Canada. I think the US is rather far behind but something
is happening in CA. Anyone want to read the site and translate it to me?
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keesan
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response 11 of 210:
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Feb 20 02:13 UTC 1998 |
A friend said there are several radio stations which also send over the web,
including one in NYC that does Indian music only. He also said I need:
a 486 with a dx chip, a sound card, and an internet provider that will handle
real-time audio (I can't imagine listening to music at the rate grex handles
internet connections). I tried 'internet radio' and found that I also need
a 28.8K modem and some downloadable software, and probably Windows or Unix.
I have none of the above. Is anyone set up to receive internet radio?
I found several partial lists of internet radio stations, including three
classical (Seattle KING-FM, which is not very readable with lynx; and one each
in England and Netherlands), and stations from Poland, Czech R., Lithuania,
Russia, Greece, Istanbul, Hungary, Malaysia, Hong Kong, Israel (see my file
radio.txt). Sounds like this may rival shortwave some day. To get the links
for the stations go to www.gnt.net/~jones/radio.htm.
I would be very interested in a demonstration.
A separate phone line is also recommended highly. (Can you set up an
internet link so that someone can get through with call waiting?).
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bmoran
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response 12 of 210:
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Feb 20 14:59 UTC 1998 |
A friend of mine is connected to mediaone, has a pretty zippy machine, and
realaudio. Last week he was listening to Radio Thailand via the net, loud
and clear, in stereo. A couple of issues ago, Monitoring Times listed a
bunch (two pages worth) of stations that broadcast over the web. Cutting
edge, or bleeding edge, I don't know, but it sure is fun!
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keesan
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response 13 of 210:
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Feb 20 19:55 UTC 1998 |
Has anyone put out a receiver for this that will let you just plug into the
phone line and not need to tie up a computer? Would your friend mind if we
came over and listened to realaudio? What is the absolute minimum system you
need, other than a phone line and internet provider? (I had no idea this even
existed a couple of days ago, and in stereo even!) Can you download things
to listen to them when not connected to the phone line? What sort of storage
capacity would it take to record off-hours? Do the foreign stations broadcast
their usual local programs, or the short-wave type programs (with more
propaganda or mostly news, actually I am not all that familiar with shortwave
but got no classical and littel folk music).
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rcurl
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response 14 of 210:
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Feb 21 06:25 UTC 1998 |
It would still be a computer, but dedicated to decoding 'web' formatted
audio.
This item stimulated me to check in at Internet Radio. I had to upgrade
from realplayer 4.0b1 to 5.0, but I'm now listening to King FM (classical)
out of Seattle, while grexing. I am using a PowerMac 7200/150 with Netscape
3.0 Gold. I haven't used this before, but I would think it would be an
enormous memory hog to record (except, I *could* attach a tape recorder -
so yes, I could "download" music on tape). While I am connected to King FN
I am also connected to Grex and another server and a web site looking for
Windows comm programs....I would think a less capable machine than this
one would serve to handle just the radio.
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keesan
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response 15 of 210:
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Feb 21 20:01 UTC 1998 |
Does this mean you are doing everything on a single phone line?!!!!
What do you think would be the minimum hardware requirements to get realaudio
on a separate phone line (and the minimum for sharing a line, if that is what
you are doing). I am expecting the last of the local broadcast classical
stations to follow in the tracks of QRS and UOM and want to be prepared with
something more than a tape library (from the public library CDs). Would you
possibly have the time to demonstrate how your system works to a couple of
novices (us) plus anybody else interested? (We can lend you our dowsing rod
in exchange, or even give a demonstration.
We had considered 'downloading' the 12-6 am. broadcasts by WUOM, but this
sounds more interesting. Don't get any phone calls then, anyway.
Have you managed to find the British and Netherlands classical stations?
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rcurl
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response 16 of 210:
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Feb 22 05:22 UTC 1998 |
Yup - one phone line. They are playing someone like Janacek now, and even
that isn't crashing the system 8^}. The selection on Internet Radio is
kind of limited, though - only KING FM is listed as a specifically classical
music station. (e-mail me to arrange demonstrations).
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keesan
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response 17 of 210:
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Feb 23 04:44 UTC 1998 |
I'd like to see that! I'll bring my own cord that only has two wires in it
to check that you are not really connected to three different phone lines
(with a 4-wire cord). You think you're skeptical, wait until you meet me!
How does the internet radio sound compared to a CD when running simultaneously
with other things, does it lower the fidelity? Are you multiplexing?
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rcurl
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response 18 of 210:
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Feb 23 05:18 UTC 1998 |
I don't have "hi-fi" amplifiers and speakers on my computer system, nor a
sound card (if that would help - I don't know), so fidelity is something
like a cheap small boom box. If other things are running, it sometimes
skips, and now and then there is a net interruption. What it is doing is
collecting packets of code that produce the music, which arrive
erratically (and not necessarily in order!) into the top of a buffer, and
take the ordered packets off the bottom. The buffer is about 20 KB. All
the other things I am doing simultaneously from the net are also getting
their data in packets, which are being sorted/stored/processed by other
software. I am not sure which hardware/software spools the audio to the
speakers so that it is not interrupted by other activity. Incidentally, I
don't use Internet Radio as I don't like background music, much less
voice, when I am trying to concentrate (even to the extent to grex....) -
but it is a marvelous technology. The "panel" has a volume control, but no
tone controls. One can have several buffers on the desktop, and switch
between them to "dial", it it takes a few seconds for the new station to
come on line.
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keesan
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response 19 of 210:
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Feb 23 15:08 UTC 1998 |
We have a CD-ROM players with a sound card, both an external and an
internal, wonder if that would fit into your system just as a test.
We may bring them along (external 1X and internal 2X?).
I prefer the music to the traffic noise. Does KING-FM have talk/news
for part of the day? (If so, hopefully it is 3 hours off from here).
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rcurl
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response 20 of 210:
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Feb 23 20:14 UTC 1998 |
I should presume the computer has sound hardware of some sort as it
has sound input and output ports. Whether the sounds is processed in
parallel to the CPU, or requires continual CPU intervention, I do not
know. Hmmm...the Tech Info manual says the 7200 has "custom sound
circuitry, DAC and ADC conversion, and a sampling rate of 44.1 or 22.05 kHz.
That doesn't answer the question, however. Anyway, the sound is continuous
while doing other things, except for intermittent gaps, so either some of
the sound processing is in parallel, or it is multitasked but too fast
to introduce discontinuities.
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keesan
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response 21 of 210:
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Feb 26 02:08 UTC 1998 |
I found two listings of internet radio stations on the web.
ontheair.com/brenta/citysort.htm Lists internet stations by city, mostly
American cities but also Australia, Greece, Auckland NZ, Austria, Belgium,
France, Canada, Italy, Netherlands, Finland (2.4 k or 112 k), Ireland,
Germany, South Thailand, Hungary, Turkey, Japan, Korea, London, Portugal,
Managua, Mexico City (9), Osaka, Padova, Iceland, Rijeka Croatia, Rome,
Taiwan, Tunisia. I think you can reach the actual music via links.
www. gnt.net/~jones/radio.htm
A shorter, more international listing (fewer US cities): Padova, Poland,
Istanbul, Hungary, Argentina, Malaysia, Brazil, Sweden, Bolivia, Holland,
Lithuania, Radio Prague, Israel, Greece.
I don't have the equipment to check these out.
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rcurl
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response 22 of 210:
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Feb 26 07:52 UTC 1998 |
ontheair.com is a bigger collection than internet.radio. Trying a little...
d'Faya?..from UK. There are 3 Michigan stations in the list (none of
them public radio, though).
www. gnt.net/~jones/radio.htm is Internet Radio
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keesan
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response 23 of 210:
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Feb 27 18:26 UTC 1998 |
Last night Rane demonstrated his internet radio system, which can, indeed,
let you do several things at once (with a slight pause in the music while
loading other things). We heard KING_FM and a British classical station, plus
a lot of western pop type stuff from around the world (even the South Thai
station is western sounding). The only problem was severe net congestion
around 8:30 p m. King FM in Seattle has traffic reports at 8:30 EST.
Radio Rijeka played love songs in Croatian, Poland had night music. But we
did not run across anything particularly ethnic sounding.
Today the friend e-mailed me:
Sindi, I tried the Internet Radio last night ... with interesting results.
1. Shonon Beach, Japan has classical.
2. Radio Slovenia had Slovenian Polkas.
3. British virgin.net had classical.
4. Radio Egypt, the most interesting, has an attractive green & gold web
site, with selections of Egyptian classical music ... among many other
radio selections. I listened to part of Abou Simbel Conc No. 1
www.sis.gov.eg )
It took 5 mins to download the newest version of RealAudio software.
Don't think I'll use it much, as both of my Internet services are limited.
That was fun, though.
Steve
Will Japan be the last bastion of classical music?
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krj
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response 24 of 210:
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Feb 27 21:00 UTC 1998 |
((( radio #203 now linked as music #115 )))
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