Hiram:
As a correction, for VDSL you do not need fiber to
the curb, but fiber to the neighborhood (about
100ft to the customer). The architecture is similar in
many ways to HFC networks, which are hybrid fiber/coax.
VDSl is in essence hybrid fiber + copper. The approximately
50Mb/sec it offers to customers is dedicated, and therefore
far superior to anything cable modems have to offer,
since each cable downstream channel will offer about
40Mb/sec as a shared medium.
Also, when you say ADSL does not run over fiber, this
is true, but all ADSL architectures aggregate ADSL
signals over fiber (there was a nice article on this
topic by George Hawley (sp?) in IEEE Communications
Magazine about 2 years ago-- he is involved with Diamond
Lane, I believe).
As a general rule, I do not believe there will be one
last mile solution which will dominate. My guess is
that the 3 contenders for business users will be
FTTC + fast/gibabit Ethernet, broadband wireless,
and VDSL. For home customers, we will probably
see a mix of cable, ADSL, and wireless by satellite
emerge. Each of the proposed solutions have strengths
and weaknesses. For cable the big cost is cable
plant upgrade, which cannot be dismissed so easily.
Similarly, FTTC is quite expensive.
Best wishes,
Bernard Levy |
