|
|
Anyone seen this?
|
gr, hwh
|
Yes I'm fairly certain that this is something a read about a month ago,
from the World DMB site.
As far as I can see it sells DAB+ as a way to cram lots more services
into a multiplex, and says sod all about the possibilities for better
audio quality. But then what do you expect with Quintin Howard being in
chairman (or what ever) of World DMB.
It also suggests that using DAB+ will always require slightly lower bit
rates because of the RS coding overhead. In reality however the addition
of RS coding will allow broadcasters to reduce FEC encoding from Level 3
to Level 4 which would more than make up for the capacity used by RS
coding. Hence this is only really an issue for broadcasters who are
already using level 4, which is virtually nobody. I wonder if they
deliberately made this part misleading so as not to shoot the old DAB
system down any more than they absolutely had to.
|
And indeed they seem to focus on reducing cost for the broadcasters.
More stations on a multiplex and lower signal levels thanks to the R/S
coding. So they ignore the fact that they could have more stations and
better quality. PL4A would give them the same reception as DAB at PL3
and more capacity, which is not important it would seem.
So they choose to have about 19 stations on a multiplex. With four
multiplexes they aim for 76 stations. Which market can sustain that
amount? Alternatively they fill up the capacity with DMB but DVB-H seems
to be more efficient at multimedia broadcasting.
gr, hwh
|
Richard E.
|
|
|