"There just isn't enough available spectrum to provide the service to thousands of customers simultaneously."
While you did stipulate "available bandwidth," I'd further qualify this statement by adding "under the present architecture." Using a different, or even a modified HFC architecture, a 1 GHz or 750 MHz channel into the home could actually be more than sufficient for the present time and for the foreseeable future. 1 GHz analog can yield several Gbps, conservatively.
More problematical, IMO, might be with the channel and service selection processes in place as it interplays with the head end, and the fact that the preponderance of "usable" bandwidth coming into the home is hamstrung with broadcast signals. This is true, whether the user elects to view what's being carried over those channels (each devouring 6 MHz), or not. The foregoing has to do with the downstream. I wont even go into the upstream again.
And this, IMO, stems from the need to continue in a model known as broadcast and select, where the actual channel selection is executed by switching between many, right at the end point (within the user's residence).
If channel selection were performed in some other manner, say, at the field node such as some VDSL or some of the greenfield Ethernet plays are suggesting, or at the host digital terminal at the central office or head end, then the majority of the bandwidth coming into the home would not be tied up with broadcast signals. It would be available for other purposes. Then again, b and c could work very nicely, one would imagine, if there were several to 10 gig of usable "digital" format available for exploitation. |
