[MLB-WIRELESS] OT-ish: the myth of spectrum scarcity

[paul van den bergen]

On Tue, 20 May 2003 11:48 am, John Dalton wrote:
> > "Interference is a metaphor that paints an old limitation of
> > technology as a fact of nature."
>
> On the research front, things seem to be heading towards the fundamental
> limits being Bit/s/Hz/(unit volume, possibly in wavelengths).  Not
> Bit/s/Hz, as predicted by the version of Shannon's Law one is taught as
> an undergraduate.  This is still conjecture.

technically, the site is right. there is no such think as interference, only 
the inability to distinguish one signal from another - e.g. it is related to 
transmitter and antenna design.  at the point when we can send and recieve 
single photons, we will have sufficient technological ability to recognise 
the potential of the arguements expressed in the article... (barring 
additional issues like attenuation due to interaction with other molecules - 
ofcourse, if one is truely ensuring interaction between source and reciever, 
then this interaction is precluded too - either the signal will be sent or 
quantum coupling will not occur and no signal will be sent). Ofcourse, this 
is all highly speculative, and until such a time as we get quantum sensitive 
antennas, I can;t see shannons limit being worked around (note: not broken.  
still applies to a given carrier frequency on a given channel.)

>
> Incidentally going way out on a limb, to me, Bit/s/Hz/(unit volume) seems
> to have a nice 'quantum electrodynamical' feel about it.  Almost as if
> information theory can be related to the fundamental properties of the
> physical world in which we live.  It just feels right (but I'm probably
> wrong! :-) ).

I jsut read a new scientist intor article on the information theory postulated 
information density of a black hole depending on it's surface area not it's 
volume.... talk about speculative (no pun intended)


-- 
Dr Paul van den Bergen
Centre for Advanced Internet Architectures
caia.swin.edu.au
pvandenbergen at swin.edu.au
IM:bulwynkl2002
"And some run up hill and down dale, knapping the chucky stones 
to pieces wi' hammers, like so many road makers run daft. 
They say it is to see how the world was made."
Sir Walter Scott, St. Ronan's Well 1824 

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