Muni network ownership and the Fourth

Sun Feb 3 14:34:58 UTC 2013

----- Original Message -----
> From: "Robert E. Seastrom" <rs at seastrom.com>

> Data point, which makes the rest of this discussion moot:
> 
> Since telcos are historically myopic and don't build (much) extra
> fiber into their plant to support future technologies, the only use
> for existing fiber in the ground in passive optical applications is to
> connect the COs. There is not enough running out towards the
> customers to support retrofitting it for PON.

It doesn't make it moot for me; I'm greenfield.

> Some more data that may inform your conceptualization - Split ratios
> of 128 and 64 only work in the lab. Proper engineering (overlap of dB
> and bits/sec/customer) will dictate split ratios of 16 or 32
> (depending on modulation scheme, and no, going to 10gbit modulation
> doesn't help; you still have the link budget problem) last time I did
> the math.

Yeah, I sorta figured this.

> Still, the power budget improvements by not going with a single strand
> active ethernet solution (which were another suggested technology and
> has actually been deployed by some muni PON folks like Clarkesville,
> TN) are huge. Imagine a 24 port switch that draws 100 watts. OK,
> that's 4w per customer. 30k customers from a served location, that's
> 120kw ($13k power bill if you had 100% efficient UPSes and 0 cost
> cooling, neither of which is true) just for the edge, not counting any
> aggregation devices or northbound switch gear.

Hmm.  the optics don't have auto power control?

> Back at NN, we discounted this as a technology almost immediately
> based on energy efficiency alone.
> 
> Anyway, in summary, for PON deployments the part that matters *is* a
> greenfield deployment and if the fiber plant is planned and scaled
> accordingly the cost differential is noise.

I assume you mean "the cost diff between GPON plant and home-run plant";
that's the answer I was hoping for.

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra at baylink.com
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