Cable networks RE: best effort has economic problems, maybe OT

Stephen Sprunk stephen at sprunk.org
Sun May 30 19:13:41 UTC 2004


Thus spake "Christopher J. Wolff" <chris at bblabs.com>
> This is a great discussion.  I'm interested in understanding these types
of
> limitations in the context of HFC cable networks.  In my opinion, HDTV
> channel bandwidth (30mhz?) ,

Broadcast ATSC (aka HDTV) uses the same bandwidth as broadcast NTSC: 6MHz.
The problem is that many (if not all) cable operators use high compression
ratios to squeeze multiple channels into a single 6MHz slot.  While this
doesn't degrade quality noticeably with SDTV, it ruins HDTV, and many cable
operators actually downconvert HDTV programming to SDTV to maintain constant
quality (lowest common denominator).

> increased demand for voip, and growing demand for IP connectivity is going
to
> stress the cable network model as well, forcing cable operators to convert
> everything to IP before going out across the wire.

Well, there's technical challenges with DOCSIS, but the bigger question is
whether broadcast content delivery is going to remain viable...

Consumers are getting used to time-shifting thanks to TiVo et al, and IP PPV
is a reality in some places.  Verizon is already talking about delivering
"cable" TV over IP once their FTTH is rolled out, and you can expect other
telcos to pick up the idea as broadband penetration increases.  Broadband
VoIP is already here; while Vonage leads the way, I doubt the telcos are
going to cede marketshare now that VoIP appears profitable (and inevitable).

There's an old saying: "I'd rather get my cable service from the phone
company than my phone service from the cable company."  We're rapidly
approaching a day consumers can get both from their broadband company.  We
may even see competition from third parties iff inter-provider reliability
and capacity is improved.

S

PS- This dovetails nicely with my recent post on how unprofitable basic
transport can be sustained through subsidies from add-on services.  Thanks
Christopher!

Stephen Sprunk        "Stupid people surround themselves with smart
CCIE #3723           people.  Smart people surround themselves with
K5SSS         smart people who disagree with them."  --Aaron Sorkin




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