Too Much Is Never Enough
The cable industry is pursuing a Data Over Cable Service Interface Specification (DOCSIS) 3.0 version that would let operators bond four or more 6 MHz channels to deliver speeds of 100 Mbps upstream and 5 Gbps down. Those speeds could mean "the ability to download a movie in seconds rather than minutes or hours," said Marwan Fawaz, CTO and senior vice president of engineering for Adelphia Communications, speaking at CableLabs’ media briefing in May. Most importantly, he said, DOCSIS 3.0 would let cable operators use existing networks. DOCSIS 3.0 will deliver 40 Mbps downstream in a single channel, which, even shared over a 250-500 home node, would be more than sufficient. "DSL (digital subscriber line) continues to compete with cable on price, and they cannot achieve our speeds," Fawaz said. "We will provide similar speeds to what’s been provided by (telco) fiber-to-the-home" for "less than one-third of the investments the RBOCs (regional Bell operating companies) are talking about. We’re not going out there and digging up trenches again." DOCSIS 3.0 will mean more than just added speed; it’s the network edge portion of the Next Generation Network Architecture (NGNA), said John Treece, senior director of Access Networks for Comcast Cable. It will be included in the developing DOCSIS set-top gateway (DSG) being implanted in next-gen digital set-tops as the industry moves to Internet protocol (IP) in the core network. "You can call it switched video broadcast if you like," Treece said. "You can call it 5,000 channels. DOCSIS 3.0 is much more than channel bonding." Fawaz said DOCSIS 3.0 will help the cable industry move into the IP space. "IPTV is not a monopoly for the RBOCs … it’s for us to deploy, too," Fawaz said, pointing out that cable then has an advantage because it has both infrastructure and content. -Jim Barthold