On Aug 27, 2009, at 10:04 AM, Leo Bicknell wrote:
In a message written on Thu, Aug 27, 2009 at 09:58:22AM +0100, Alexander Harrowell wrote:
An interesting question: as the population gets sparser, the average trench mileage per subscriber increases. At some point this renders fibre deployment uneconomic. Now, this point can change:
This statement makes no sense to me.
The cost to dig a trench is cheaper in rural areas than it is in urban areas. A lot cheaper. Rather than closing a road, cutting a trench, avoiding 900 other obsticals, repaving, etc they can often trench or go aerial down the side of a road for miles with no obsticals and nothing but grass to put back.
So while mileage per subscriber increases, cost per mile dramatically increases.
I think you meant, "decreases", here. Marshall
The only advantage in an urban enviornment is that one trench may serve 200 families in a building, where as a rural trench may serve 20 familes.
But more puzzling to me is the idea that fiber becomes uneconomic. This may have once been true, but right now you can buy 10km or even 40km lasers quite cheaply. Compare with copper which for even modest speeds requires a repeater every 2-4km.
If you have to reach someone 20km from the CO, the cost of running the ditch-wich down the road in a rural area is not the dominate cost over the next 20 years. It's equipment. If the copper plant takes 4 repeaters to do the job, that's 4 bits of equipment that can fail, and will need to be upgraded at some point. Running something as simple as point to point fiber they can be provided with GigE speeds today with no intermediate equipment; the cost of a 20km GBIC is far less than the cost of installing 4 repeaters.
The problem with all of these is ROI, not cost. Somewhere along the line we've decided very short ROI's are required. Do you work at a company where an ROI of over a year is laughed at? When the original rural telephone network was pushed ROI's of 50 years were talked about. There's plenty of infrastructure built every day with ROI's of 20 years.
So it would cost $2000 per home to put in fiber. The margin on the service is $5 per month. It's a 33 year ROI. That's ok with me, it's infrastructure, like a road, or a bridge. We're still using copper in the ground put in during the 60's, 70's, and 80's.
-- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/