Muni Fiber (was: Re: last mile, regulatory incentives, etc)

Tue Mar 27 16:55:54 UTC 2012

On Tue, Mar 27, 2012 at 1:45 AM, William Herrin <bill at herrin.us> wrote:

> On Mon, Mar 26, 2012 at 8:04 PM, Jacob Broussard
> <shadowedstrangerlists at gmail.com> wrote:
> > Who knows what technology will be like in 5-10 years?  That's the whole
> > point of what he was trying to say.  Maybe wireless carriers will use
> > visible wavelength lasers to recievers on top of customer's houses for
> all
> > we know.  10 years is a LONG time for tech, and anything can happen.
>
>
Regarding lasers. I agree that modulating a laser beam to carry information
is a great idea. Perhaps, though, we could direct the beam down some sort
of optical pipe or waveguide to spare ourselves the refractive losses and
keep the pigeons and rain and whatnot out of the Fresnel zone. We might
call it an "optical wire" or "optical fibre" or something. no, it'll never
catch on...

Hi Jacob,
>
> The scientists doing the basic research now know. It's referred to as
> the "technology pipeline." When someone says, "that's in the pipeline"
> they mean that the basic science has been discovered to make something
> possible and now engineers are in the process of figuring out how to
> make it _viable_. The pipeline tends to be 5 to 10 years long, so
> basic science researchers are making the discoveries *now* which will
> be reflected in deployed technologies 10 years from now.
>

I recall an Agilent Technologies presentation from a couple of years back
that demonstrated that historically, the great majority of incremental
capacity on cellular networks was accounted for by cell subdivision. Better
air interfaces help, more spectrum helps, but as the maximum system
throughput is roughly defined by (spectral efficiency * spectrum)* number
of cells (assuming an even traffic distribution and no intercell
interference or re-use overhead, for the sake of a finger exercise),
nothing beats more cells.

As a result, the Wireless Pony will only save you if you can find a 10GigE
Backhaul Pony to service the extra cells. After a certain degree of
density, you'd need almost as much fibre (and more to the point, trench
mileage) to service a couple of small cells per street as you would to
*pass the houses in the street with fibre*.

One of the great things FTTH gets you is a really awesome backhaul network
for us cell heads. One of the reasons we were able to roll out 3G in the
first place was that DSL got deployed and you could provision on two or a
dozen DSL lines for a cell site.

You can't have wireless without backhaul (barring implausible discoveries
in fundamental mesh network theory). Most wireless capacity comes from cell
subdivision. Subdivision demands more backhaul.

> There is *nothing* promising in the pipeline for wireless tech that
> has any real chance of leading to a wide scale replacement for fiber
> optic cable. *Nothing.* Which means that in 10 years, wireless will be
> better, faster and cheaper but it won't have made significant inroads
> replacing fiber to the home and business.
>
> 20 years is a long time. 10 years, not so much. Even for the long
> times, we can find the future by examining the past. The duration of
> use of the predecessor technology (twisted pair) was about 50 years
> ubiquitously deployed to homes. From that we can make an educated
> guess about the current one (fiber). Fiber to the home started about
> 10 years ago leaving about 40 more before something better might
> replace it.
>
> Regards,
> Bill Herrin
>
>
>
> --
> William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
> 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
> Falls Church, VA 22042-3004
>
>