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[EFM] RE: Wavelength allocation


Thanks for your explanation. You have raised many important points. Some of
them are easy to spot, but others are quite easy to overlook. Our group at
CTBC has already thought a lot about this problem, and I can share some of
our insights on it.

1) We reached a consensus on downstream video only. The upstream channel is
not really needed; it would cause more problems than benefits. At least in
our particular case, it makes no sense to support cable modems over a
network that already provides Ethernet service. Other carrier's
requirements may be completely different.

2) The use of extra connectors and filters is another interesting tradeoff.
We're willing to have them over the network, to allow us to selectively
control which services/wavelengths will end up reaching which users. We
don't have a official position on this issue, though; it will depend on a
more thorougly technical and cost analysis of the entire solution. Bear in
mind that flexibility and simplicity for the operational crew are part of
our goals.

3) On amplifiers, we want to avoid them, or at least minimize their use.
It's costly, and although very efficient, it's not perfect, as it may cause
some collateral effects (as you have stated in the analog video case). In
this point we at CTBC have a comparative advantage, because we are already
used at keeping our current copper network short (mean distance less than
500 m/~1500 ft, in fact). We use DLCs extensively, and I believe we are
going to make something similar for FTTH when the time comes. Again, this
is not a final decision, and our position may change in light of the facts.

Carlos Ribeiro
CTBC Telecom