The thing is, cable systems ARE broadband. Some DSL methods use broadband
transits, especially on the last mile. Anything transiting HFC is using
broadband as a part of the link. FrameRelay has many of the same constrants
as HFC cable, but is definitely a baseband technology.
The reason that HFC has such horrible aggregation congestion effects is that
the head-ends are over-commited. Fewer clients per head-end would eliminate
the bottle necks, as would a larger return band, or application of
spread-spectrum technologies on the HFC medium. (At PacBell/ACN, this was
the subject of much debate, business economics won out. We had cost targets
to hit, at ~400 homes passed per HFC head-end.) The same is true for many FR
clouds. I'm looking into 802.11b regional wireless systems right now and am
seeing the same things.
BTW, for the audience, 802.11b is definitely broadband, as is any other
wireless technology. The real kicker is how many of those companies will be
around one year from now?
ALSO, some advocates of broadband don't realize that GigE is baseband at
1Gbps. Getting it on broadband would require a 4GHz carrier and would pretty
much saturate the spectrum. Now I'm getting really far from my BSEE days and
let the RF guys take it over (if we have any here). At PacBell/ACN, we had a
10MHz return band, on a 750Mhz HFC system. Of course, I couldn't understand
why we couldn't allocate an entire digital video band for the purpose
<grin>. But, the only routing was at the super head-end. The head-ends were
never considered to have return data, in the original design.