On 1/12/12 5:40 PM, Jeff Liebermann wrote:
On Thu, 12 Jan 2012 09:52:47 +0100, hwh
wrote:

On 1/12/12 8:10 AM, Jeff Liebermann wrote:
Incidentally, there's another nightmare pending, that oddly involves
yet another potential source of GPS interference. In EU, the official
future all digital broadcast band is 1452 to 1492 MHz. There's no
hardware, and several countries are just sitting on the spectrum, but
that's the official ITU dictated direction for S-DAB.

No, the official EU digital (radio +) band is 174-240 MHz. The 'L-band'
you mentioned has been used for digital radio, but it is not suitable
for terrestrial distribution because the frequencies are too high. There
now remain a few transmissions from satellite and just a few thousand
receivers scattered around the continent. I wonder what will happen to
the frequency allocation in 2012.

gr, hwh

I can't predict what will happen in Europe, but in the US, I think
1.5Ghz would be a likely place to move digital radio. How it will be
organized and structured is beyond the abilities of my crystal ball.

As for being unsuitable for terrestrial, please note that Sirius is
using 2320 to 2332.5MHz and XM at 2332.5 to 2345MHz. While allegedly
a satellite based DAB system, much of the urban coverage is via
terrestrial repeaters, primarily to deal with "urban jungle" building
blockage. If 2.3Ghz works, certainly 1.5Ghz will also work.

Sirius uses a dual distribution system, with satellite and terrestrial.
In Europe they tried to use L-Band for terrestrial-only and that doesn't
work. You simply needed too many repeaters, making the system too expensive.

Satellite broadcasting does not work in Europe because there are many
markets. They are too small to make them viable targets. Band III
systems need less transmitters and can easily be split into many
markets. The end of analog TV freed up significant portions of the band
for digital radio (and other services sharing the multiplexes). Digital
TV is moving to UHF-only in many countries, even in less airspace than
before because governments want to cash in on frequencies for mobile
internet. No significant use has been decided (yet) for Band I frequencies.

gr, hwh