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Depending on the modeling assumptions, these itemized costs can vary dramatically.
Let??™s take central office costs as an example: is an allocated share of the OLT the only
cost included; or must the model also account for the costs of the PSTN gateway, the
video distribution network, connections to ISPs, central office real estate and facilities,
and so on? In other words, which elements of the network must be charged to the EPON
deployment and which can be treated as sunk costs? Similar decisions must be made in
modeling the costs of the outside plant, and it is worth noting that outside plant costs
traditionally dominate such a deployment, with labor costs representing the largest
component. Even though we cannot construct a generic bottom-up model here, we can
get a top-down estimate for the magnitude of per-subscriber costs by using a 2005 published
report on planned fiber-access spending by NTT, which stated that NTT foresaw
investing $42 billion over a period of five years to provide fiber-based services to 30 million
homes and businesses [23]. This leads to a simple estimate of $1410 per subscriber.
Although this single number does not shed any light on the constituent costs or on what
will be treated as sunk costs for this deployment, it is in line with typical estimates for
EPON/FTTH per-subscriber costs.
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