Re: gEDA-user: Building the PCB+GL branch [WAS: Re: Open GL survey (for PCB)]

[Dave McGuire <mcguire@xxxxxxxxxxxxx>]

On Feb 6, 2009, at 1:02 PM, der Mouse wrote:
>>> They are?  DSL certainly isn't (the baseband there is the audio
>>> range, which DSL specifically avoids) and,
>> My definition of "broadband" is "multiple communication channels
>> sharing bandwidth on the same medium", which does not, IMO, describe
>> DSL.  What is yours?
>
> The one from which my remarks were derived came from googling and
> reading three or four pages which gave definitions, such as
> http://en.wikipedia.org/wiki/Baseband and
> http://en.wikipedia.org/wiki/Broadband.  It is that baseband uses the
> frequency range whose low-frequency end is at 0Hz; broadband avoids
> this, with its low-frequency cutoff well above that.  As the
> "Broadband" wikipedia page points out, the term can also refer to any
> signal whose bandwidth is wide compared to something else, but that's
> not a very useful definition in this context, as there is no obvious
> "something else" to compare to.

   Yes, and that is (as far as I know) the "new" (and incorrect)  
popular definition of "broadband", brought about by clueless  
marketing types at ISPs several years ago.  A "band" that is "broad",  
rather than (or in addition to) "several channels of RF on a wire".

> Actually, channels sharing bandwidth can happen on baseband or
> broadband, via either TDM or FDM (though whether FDM is baseband
> depends on your point of view; an FDM-shared medium is not baseband  
> for
> more than one of the signals making it up, though if you think of them
> as aggregated then the term may be fair).

   Sure thing.  But what we're talking about is "several channels of  
RF on a wire".

   I'm aware that language is an evolving thing, and definitions  
change and new ones are developed...but it sure is irritating.   
Today's kids will grow up thinking "broadband" means "lots of  
bandwidth", while me, having grown up (at least chronologically!) in  
the 1970s, "broadband" is a more relaxed way of saying "multiple  
information channels via frequency-division multiplexing on multiple  
independent carriers".

            -Dave

-- 
Dave McGuire
Port Charlotte, FL




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