Eric,
"Dave Horne (I think) answered 4 Terabit. I've been a hardcore ATHM believer ever since. Who needs fiber to the home? Whats all the fuss about cable being bandwidth limited?"
Dave doesn't need me to speak for him, but if he said 4 Terabits he was very likely referring to the optical component of the HFC, not the coaxial delivery segment to the home.
The boundaries of the coaxial end point are in the range of roughly 1 GHz along the last mile, translating roughly to between 10 to 20 Gb/s, depending on the type of QAM or other bit optimizing modulation scheme which is used. For surety purposes, it's probably lower than that.
The 4 THz to 14 THz range of permissiveness exists on the fiber portion of the HFC, assuming it is designed properly using the proper grade of glass, and not the delivery potential to the coaxially-based end point.
This is precisely why I made reference to eliminating the coaxial end point component entirely, yesterday. As for the 150 to 1 ratio, that is the total spectrum allocation which must be shared with umpteen other offerings that the cable cos have on their agenda, including voice, interactive, regular TV programming, etc.
The ratio would be more like 150,000 + to 1 if they removed the coaxial parameters from the formulae.
Regards, Frank Coluccio |
