Re: Larry Page wants "Wi-Fi on Steroids"

[David Farber <dave () farber net>]

Begin forwarded message:

> From: "David P. Reed" <dpreed () reed com>
> Date: May 26, 2008 1:55:26 PM EDT
> To: David Farber <dave () farber net>
> Cc: ip <ip () v2 listbox com>
> Subject: Re: [IP] Re:  Larry Page wants "Wi-Fi on Steroids"

> While ducting is an interesting phenomenon, as are other propagation
> modes, one should be a little cautious about claims of "interference"
> that rely on analogies from long-range AM or FM broadcast propagation.
>
> Neither AM nor FM is a digital modulation technology, neither uses
> modern coding techniques.  (FM has a bit of a "capture effect" but  
> that
> depends on the particular receiver architecture employed - it's not
> digitally coded).
>
> Superposition of signals that result from "ducting" need not disrupt
> channels.   For example, NTSC TV pictures degrade badly based on noise
> because so little of the NTSC channel capacity is devoted to picture
> signal (lots is devoted to retrace pulses and other things).  But a
> comparable digitally encoded picture given the same channel will
> tolerate a great deal of superposed noise, without any loss of picture
> quality.
>
> When we are talking about "white spaces" it is crucial to understand  
> the
> systems design of the system being used.   Ducting may or may not be
> crucial.   It may be possible to design around ducting.   It may be
> possible to ensure that ducted signals don't disrupt legacy systems,
> because the legacy systems are largely of fixed design.
>
> Ham radio operators are NOT necessarily experts in information  
> theory or
> electromagnetic waves.  To get a ham license, one merely has to  
> answer a
> set of multiple-choice questions that are based on cookbook
> understanding of radio systems that go back 50 years.
>
> That said, the converse is not true.  Many ham radio operators ARE at
> the highest end of one or more areas of technology that pertain to
> radio.  So I would suggest that the proper way to understand these
> issues is to discuss them based on the physics and information theory
> and circuit designs that are used in radio systems.  Claims of  
> authority
> from experience with unrelated systems are less valuable when  
> looking at
> newly invented technologies (like the best whitespaces work).
>
> David Farber wrote:
> > ________________________________________
> > From: ken [Ken () new-isp net]
> > Sent: Saturday, May 24, 2008 12:07 PM
> > To: David Farber
> > Subject: Re: [IP] Larry Page wants "Wi-Fi on Steroids"
> >
> > Dave,
> >
> > As any HAM radio operator will confirm, when you use the lower end of
> > the RF spectrum, a phenomenon known as "ducting" or "skipping" occurs
> > when certain atmospheric conditions occur.
> > http://www.tvtechnology.com/features/On-RF/f-DL-signals.shtml
> >
> > This is a phenomenon many of us older folks will recall from  
> > childhood,
> > back in the day when all television programming was delivered off-air
> > and television stations used to routinely shut down overnight.
> >
> > Growing up in the Boston area our three television stations used to  
> > stop
> > broadcasting early in the evening on weekdays and once in a great  
> > while
> > I could enjoy Philadelphia programming, in perfect clarity, since  
> > they
> > broadcast later into the night.
> >
> > The "White Space" band we are about to put into use for broadband is
> > exactly that same slice of spectrum and the same problem is going to
> > occasionally occur, one that will cause incredible difficulty if we
> > look at the potential for interference this will provide.
> >
> > While I support any additional spectrum that might be added to the
> > available bands, this is not what I would consider to be an optimal
> > choice.
> >
> > An alternative suggestion that I would prefer to see implemented, one
> > that the FCC has shown a willingness to allow, is the spectrum  
> > sharing
> > concept. This idea would mandate licensed bands accommodate a "low  
> > power
> > underlay" that would regulate output power equal to today's 2.4GHz  
> > WiFi
> > equipment. As you are probably aware, many of the licensed bands in  
> > the
> > US lay fallow in most, if not all, of this country and even in  
> > locations
> > where these bands are currently in use, they are granted a far  
> > greater
> > output power than these proposed devices. Naturally, this would  
> > make it
> > impossible for any low power device to cause interference with them.
> >
> > Respectfully,
> >
> > Ken DiPietro/CEO
> > NextGenCommunications
> > Home/Office (301)789-2968
> > www.NextGenCommunications.net
> > Communications without Concessions
> >
> > PS - I would like to give credit to Dewayne Hendricks for pointing  
> > this
> > issue out to me. While I was previously aware of the ducting  
> > phenomenon
> > I had not thought about the possible issue as it applied to this use.
> >
> >
> >
> > On Sat, 2008-05-24 at 11:17 -0400, David Farber wrote:
> >
> > > Why insanity?
> > >
> > > On May 24, 2008, at 8:42 AM, ken <Ken () new-isp net> wrote:
> > >
> > >
> > > > Perhaps Congress can initiate steroid abuse investigations into  
> > > > this
> > > > insanity, as well.
> > > >
> > > > Respectfully,
> > > >
> > > > Ken DiPietro
> > > > New-ISP/NextGenCommunications
> > > >
> > > >
> > > > On Sat, 2008-05-24 at 08:00 -0400, David Farber wrote:
> > > >
> > > > > <http://googlepublicpolicy.blogspot.com/2008/05/larry-page-talks-about-googles-vision.html
> > > > >
> > > > >
> > > > >
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> > Ken DiPietro/CEO
> > NextGenCommunications
> > Home/Office (301)789-2968
> > www.NextGenCommunications.net
> > Communications without Concessions
> >
> >
> >
> >
> >
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