[BC] to the editor of the NY Times

[Dan Dickey]

This idea was afforded the broadcast community in the U.S. many years ago. 
They soundly rejected it.  The reasons are clouded in almost everyone's 
mind.  But probably the biggest issue had to do with the idea that the DAB 
inventors had about how to deal with multipath.

Multipath can be defeated in a number of ways.  But one of the better ones 
is to widen the spectral occupancy of the signal.  Then multipath affects an 
every smaller percentage of the total energy transmitted.  So the DAB 
designers opted for a channel width over 1MHz.  Now this is a great thing 
for multipath mitigation.  But it is a nightmare if you are limited to a 
small amount of spectrum and have a lot of stations as we do in the U.S. 
However the DAB inventors had a solution to that too.  Just put lots of 
programs into each transmitter.  In Europe this is not a problem because 
most transmitters are owned by a few network operators and they could easily 
manage the allocation of audio streams across their available transmitter 
network.  But in the U.S. there is no one willing to manager this sharing of 
transmitters amongst the several stations.

In the U.S. all the bands that DAB was designed for (band III & L) are 
already occupied but it would seem that this was a solvable problem if it 
were not for the previous one.

Best regards,
Dan Dickey

>I clicked on a couple of the receivers and discovered something
> interesting. There is a separate DAB band from 174 to 240 mhz.  I
> realize of course that this part of the spectrum is already occupied
> in the USA. However it seems to me that there is no technical reason
> that a similar slice of spectrum could not be found in the USA to
> accomplish the same thing.