----- Original Message ----- > From: "Robert E. Seastrom" <r...@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 j...@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA #natog +1 727 647 1274
