Thus spake "Christopher J. Wolff" <chris@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