Hello,

Purely an academic question to satisfy my curiosity, but of the main
digital broadcast systems:

DVB
DMB
ISDB
ATSC

Is there any one which is technically superior to the others?

Thanks in advance,

Roger Melly

--
conkersack
gmail
com

conkersack@googlemail.com wrote:
> Hello,
> 
> Purely an academic question to satisfy my curiosity, but of the main
> digital broadcast systems:
> 
> DVB
> DMB
> ISDB
> ATSC
> 
> Is there any one which is technically superior to the others?
> 

There has been a huge debate raging over DVB and ASTC, I think at the 
last count experts in the US said their ATSC standard suits them better 
because it is more power efficient and used over bigger distances, 
whereas the EU DVB standard is better in cities with lots of relections, 
or through tree where there is alot of fading.

Communications theory basic says you can any 1 thing you want but you 
have to trade robustness against efficiency.

Its a little like 802.11g wireless standard, 11b actually can go longer 
distances, but 11g is more robust against interfernce and has a higher 
bit rate.  It drops off more sharply as it hits the noise floor.

Some will argue that DVB was designed with more resouces and later than 
ATSC and is therefore more advanced.

In my experiemce I have heard the US have had many problems that would 
have been fixed by changing to DVB, and in the UK many have had problem 
with reception simply because the signal level at their aerial was too 
low.  Both seem to be coping now with various adaptations in aerial use 
and receiver performance.

--
Tony

On 25 Aug., 23:38, conkers...@googlemail.com wrote:
> Hello,
>
> Purely an academic question to satisfy my curiosity, but of the main
> digital broadcast systems:
>
> DVB
> DMB
> ISDB
> ATSC
>
> Is there any one which is technically superior to the others?
>
You cannot just claim one is best for everything and
one is worst.   They are also of different generations
with the Chinese DTMB (DMB-TH) being the newest
(currently in production).
DVB-T is old and is very weak in many areas, but it is
designed for SFN operation. It has a rather large
overhead when larger SFN are used.
(64QAM  MFN 24.13 Mbps / SFN 19.19 Mbps)
DVB-T is not very sensitive to echo's.
>
ATSC is claimed to be better in signal robustness
than DVB-T (works with less signal or more noise).
>
The new DVB-T2 has many more modes of operation,
is very flexible and is very much better than DVB-T
and likely the best  standard in almost all technical areas.
>
The DVB-T2 32k mode, that is intended for fixed aerials,
will however not be very good in trains and cars. It will
be sensitive to Doppler effects when the receiver moves
to or from the transmitter.
But the 32k mode  will be very bit-rate efficient
even when used in SFN's.
>
DVB-T2 and DTMB is using the same kind of
error correcting codes - LDPC/BCH - but DVB-T2
has a wider choice of code rates.
DVB-T is using the much less efficient
convolutional codes (Viterbi) followed by a RS code.
(DVB-H even adds an extra layer of RS codes
for even more over overhead).
>
There is a lot more, but a
> academic question
could need a little academic research
by yourself.
>

Lars :)

On 26 Aug, 10:38, Tony  wrote:

 [snip reply]

Cheers man.

On 26 Aug, 11:36, res...@gmail.com wrote:

[snip]

> There is a lot more, but an academic question
> could need a little academic research
> by yourself.
>
>
>
> Lars :)

Thanks Lars - I should have guessed that there'd be more to it than
I'd have thought!

What about the ISDB system? How does that compare?

On 26 Aug., 15:50, conkers...@googlemail.com wrote:
> On 26 Aug, 11:36, res...@gmail.com wrote:
>
> What about the ISDB system? How does that compare?

Sorry"   'no  speak  Japanese'.

But it is one  of the older standards.

In Europe DVB standards will be the only
standards used for DTT in the foreseeable
future. DVB-T2 is very very close to the
theoretical performance limit.

Lars :)

On 26 Aug, 15:30, res...@gmail.com wrote:
> On 26 Aug., 15:50, conkers...@googlemail.com wrote:
>
> > On 26 Aug, 11:36, res...@gmail.com wrote:
>
> > What about the ISDB system? How does that compare?
>
> Sorry"   'no  speak  Japanese'.
>
> But it is one  of the older standards.
>
> In Europe DVB standards will be the only
> standards used for DTT in the foreseeable
> future. DVB-T2 is very very close to the
> theoretical performance limit.
>
> Lars :)

Ah, OK! Thanks again for your replies, Lars!