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How will T-DMB in France be implemented
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France decided to use T-DMB as their radio standard instead of DAB+.
At least that was what I understood a few month ago. T-DMB was never
meant to be used as a radio standard. My question is, does any one
know how they will implement. Will they, like for video is defined,
use a single TS per radio service or will they combine multiple audio
streams into one TS. If the latter is the case, how will they
implement signalling.
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The implementation of T-DMB is composed of 1 video service and 1 audio
service and sometimes 1 data service (BIFS) per subchannel like it is
describe in TS 102428. The video service use a very low frame rate.
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I know the TS 102427 and TS 102428 quite well. That's not my issue.
The France regulators decided to use T-DMB as a Radio standard,
instead of DAB+. In fact, TS 102 428 excludes audio only (radio)
transmissions although an example of audio only is given in the
appendix. So still the questions remains how intends France to
implement DAB radio, using the T-DMB standard
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I'm sorry but Nicolas did reply to your question, hasn't he?
A DMB datastream consists of a single very low speed video-stream (more
a video slide-show then real video) and one single audio-stream.
Anycase, this is the most logical thing to do as this is also best for
portable reception. A receiver tuned to one particular service (as most
radios tend to be) only needs to receive and decode this one particual
DMB-stream and can be switch of the receiver chip-set when the other
services are transmitted.
This saves power which is very important for portable receivers.
Cheerio! Kr. Bonne.
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You can do something called visual radio with a very low bitrate for the
video part. so it will loks like a permanent slide show with one new
picture up to every 2 seconds. In this case you have the audio and video
object.
Nicolas Croiset VDL
http://www.vdl.fr/
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Nicolas Croiset VDL
http://www.vdl.fr/
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You can listen to this program in french to have a better understand
of the french choice.
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Why do the French have to be so different and awkward every time?.
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Demand an answer from your XYL when she gets back, Tony ;-)
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I can only acknowledge this. I just got back from two weeks in the var:
and -except for the occasional shower (which was welcome from time to
time)- we had 25 to 30 degrees almost all days.
The coast is -if you ask me- a little bit too hot: 30 to 35 degrees. I
prefered the slightly inland areas which where cooler because of the
mistral wind.
Cheerio! Kr. Bonne.
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Well, because they had the choice of different technologies and picked
this one.
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Not exactly. The French government forced the broadcasters to come up
with a standard in a very limited time frame. Another constraint was
they only were allowed to choose an existing (published) standard.
DAB+ wasn't published, T-DMB was
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See Nicolas's comment.
Anycase, where did you see the reference to the constraint that only
published standards where excepted.
And it looks that the comments of the broadcasters that where published
did not realy care that much about this constraint because there where
comments favouring almost any technology that existed including DABv1,
DAB+, DMB, DVB-H, S-DMB, DRM and even IBOC-FM.
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Not exactly, the T-DMB had been chosen by the content providers (GRN).
Then the government and radio authority follow this way.
Nicolas Croiset VDL
http://www.vdl.fr/
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As we are heading towards a multi-technology broadcasting-world anyway,
we will see receiver-chips which can do DABv1, DAB+, DMB, FM, AM, DRM,
IP (wifi), bluetooth, UMTS, .... so I do not really see that much of a
problem.
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I do. As a technician it is a challenge to implement and integrate the
different standards. For a set maker it is a burden. It means
additional development costs and risks
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That does not seams to be the possition of the chip-manufactors and the
makers of the receivers.
I remember an series of radio-programs on digital radio back in 2002 on
"radio corax" (a local radio-station). One of them was a discussion
between radio-station operators, radio-manufactorers and regulators
where the chief technical engineer of blaupunkt simply pointed out that
they concidered different technologies to exist next to eachother (the
talked about DAB, DRM and satellite in these times) and have it all in
one receiver.
Look at the chipsets of frontier silicon (to give you one example).
Current chipsets already do DAB, FM, RDS, MP3, WMA, USB and AAC.
Other chipsets combine DAB and DMB-T.
The only reason I see NOT to add certain technologie might be related to
licencing-costs of certain technology (especially AAC) and this can
simply be done by having certain technology already inside the chipset
but have it disabled.
That way, the chip-manufactorers only need to design one single chip.
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So if you travel to France in future the car radio won't work....
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The difference between DAB+ and DMB-radio is minimal and in fact just a
matter of how the bits are packaged, so I do not think this will be a
real issue.
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It can be done, but again from a set makers perspective it is not
nice. From the broadcasters perspective, they don't care, they always
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They seams to have a different perspective on this. For them, it's just
a question of what chipsets to use.
The choice of (say) combining terrestial broadcasting with satellite or
DAB and DRM has more impact than designing a DAB+/T-DMB radio.
As least, you do not need to take care of additional RF-componenent and
antenna's.
From the broadcasters perspective, they don't care, they always
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support a single standard. From Worlddmb's perspective it is also not
positive, since it is in their advantage to have a single european
standard at the end (DAB+)
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Mind you hardly any cars in Britain are fitted with DAB radios anyway so
no real problem. I suspect that 162 AND 262 kHz will be around for a
long time yet!......
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I think you got something wrong.
162 is France Inter, but there is no station on 262 Khz.
On longwave, there are three other frequencies used by french-language
stations: 183 Europe1 (althou this is officially a German station), 216
RMC info (althou I doubt you can receive this station in the UK) and RTL
on 234 KHz.
More info here:
Cheerio! Kr. Bonne.
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The worlddrm concortium supports both DAB and DRM, and -to some degree- DRM.
As long as the chipset manufactors make chipsets that support both DAB+
and radio-over-DMB (as it looks it will be the case); this is all prety
much a trivial question.
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The only difference I see between DAB+ and DMB-radio is how a additional
services are multipled into one stream.
- In DAB, you have to stuff them into the X-PAD part of the MPEG (or
AAC)-frames.
- In DMB, you use a "higher" layer to multiplex the different services
stream.
Apparently, the broadcasters and ART expect additional services besides
the audio-service to become "normal practice" in the future, and hence
the choice of DMB for radio instead of DAB+ is not that unlogical.
Another element can be that the DMB-system allows for a
multiplex-operator to sell bandwidth as one block (e.g. x. CUs) to a
broadcaster, which can contain multiple audio-streams (radio-stations).
In this senario, the generation of the DMB-stream is done by the
broadcaster (which can contain whatever HE likes to be in there: one
audio-stream, multiple audio-streams, other streams, ....) and this
complete transport-stream is sent to the mux-operator which then inserts
it into the multiplex stream.
This way, the choice of what is inside the DMB transport-stream is
completely managed by the broadcaster which is the most logical thing to
do (as he is the end-customer) and for the business-model in France (and
the UK); where you have large broadcasting-groups operating multiple
stations, it does a more "logical" approach.
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Hi Kristoff,
the TS 102428 allow only one audio and video object with optionally a
data object. The DMB TS have also a lot of values fixed by default and
it is impossible add more things inside the TS whithout changing the
spec.
Big groups generally provide directly the ETI stream to broadcaster and
provide all their stations inside, then the technicla operator choose
the subchannels to broadcast on each location by remuxing the ETI
stream.
Nicolas Croiset VDL
http://www.vdl.fr/
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Finally you come to the haert of what my question was, although no
real answer is given yet. My question was does any one know how the
French will implement DMB radio. A single TS per audio stream or
multiple audio streams per TS. The latter is not allowed by the
standard and will realy complicate the control stack, since one has to
combine MCI/SI from the DAB level and SI/PSI from the TS. My
conslusion is that this knowledge is not yet available
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We will see, but -concidering the power-saving issues of having a single
audio-service per TS- and Nicolas's comments, it looks to be one
audio-service and a very low-bitrate video-stream per DMB TS.
(as Nicolas already explained).
Cheerio! Kr. Bonne.
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But this senario does contradict the "power saving" technique of just
having a single audio-stream per DMB transport-stream as I just
explained in my mail to Willem.
Cheerio! Kr. Bonne.
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Depends on the (car) radio manufacturers. France is big enough to
include the standard in receivers, but manufacturers are not glad
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If France go ahead and use T-DMB then receiver manufacturers would
probably implement it in addition to DAB+. Otherwise they would have to
build two sets of receivers. One for France and another for all the DAB+
countries.
It would probably just be a matter of software (and ignoring the video
stream, if the radio doesn't have a screen). So in that case your radio
probably would work when you go to France.
Richard E.
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