"It seems to me now that the cost points on DWDM, particularly environmentally hardened 100+ channel DWDM, are critical to last mile cable (or possibly 10G) deployment success"
That's correct. We need to see wdm costs come down to the point where individual lambdas are priced at $2 to $20 each, not $15,000 to$20,000 each. It's still more economical to deploy more fibers for the distances we're talking about right now, as opposed to implementing the type of wdm that can give us the channel spacing (grid) needed to achieve the number of users that make sense.
As to whether services on PON are shared or split, it comes down to semantics, IMO. In addition to the contention mode that is characterized by collision domains, which is what I think you are singularly referring to as "shared", there are other methods of media sharing such as time division, frequency (wavelength) division, code division, etc.
When there is only a single physical member (e.g., a fiber strand, or a coaxial cable, or twisted pair) to the residence, it is being shared by all of the applications that simultaneously ride over it, even if those applications are not in direct contention within the same spectrum-defined channel. For example, voice over cable that uses a circuit switched mode does not compete with the Olympics that are being aired by NBC. Voice has its own frequency slice, as does the program video channel.
VoIP over cable is a another matter. Here you are using the data channel associated with Cable Modem (perhaps some operators may use the STB data link in the future, instead or as well), and this now falls under the classification of sharing in a queued system, although I would assume with some degree of prioritization for voice. Would you or someone else confirm this last part about priroritization? TIA.
FAC |
