Harmonic's pitch is that Docsis Lite would be less complicated and less expensive than a modular-CMTS (M-CMTS) scheme, which physically separates the cable upstreams and downstreams. Docsis Lite also requires less processing than sending the IPTV signals directly through the CMTS, Harmonic senior manager of cable solution and strategy Yoav Derazon told Cable Digital News at last week's TelcoTV show in Orlando, Fla.
CMTS bypass isn't exactly a new idea (more on that later). Harmonic's proposal differs from some others by adding software to the installed CMTSs -- namely, enhanced DEPI (Docsis External Physical Interface) control for edge QAM session management. There's a similar requirement at the edge QAM for session provisioning and Docsis MAC encapsulation, which ensures that IPTV streams can be understood by Docsis cable modems.
As for the edge QAM itself, Docsis Lite proposes using an IPTV-optimized unit that costs around $200 per unit plus another $150 for the Docsis management component, per Harmonic's figures. The idea, Derazon says, is to use inexpensive but "good enough" edge QAMs to handle bulky, bandwidth-intensive IPTV service flows, without requiring the processing and advanced routing of a regular CMTS.
Harmonic is circulating the Docsis Lite proposal at CableLabs and among the larger MSOs. A CableLabs spokesman had no comment when asked if the Louisville, Colo.-based R&D house was weighing Harmonic's software additions for possible inclusion to the Docsis specifications. Back in May, CableLabs confirmed it didn't have a cable IPTV specification underway.
In the meantime, Harmonic is starting to make some progress with Direct-To-Edge (D2E), another architecture that pipes IP video directly through edge QAM devices. Butler-Bremmer Communications, an Iowa-based telco, is using D2E to deliver IPTV services on its cable plant. Harmonic has a much larger D2E deployment going in South Korea with SK Broadband . Other service providers are on board with D2E but haven't been announced. (See Iowa Cabler Gets Wired for IPTV.)
Harmonic's not alone
Harmonic isn't the only vendor trying to skin cable's IPTV cat. Some examples:
BigBand's approach also requires some new software, including a small software client in the modem that communicates back to the vIP PASS server.
Instead of floating a broad proposal, BigBand is developing technology integration partnerships with makers of digital rights management systems, Docsis modems, and Docsis modem chipsets. (See BigBand IDs IPTV Partners .)
Everybody yell 'NGAA'
The big wild card here is the Next Generation Access Architecture (NGAA) project, in progress at Comcast Corp. (Nasdaq: CMCSA, CMCSK) The idea is to deliver digital video (either via IP or cable's traditional MPEG transport) through a CMTS on the cheap, in anticipation of more and more video traffic going narrowcast.
Sources say NGAA ties into the MSO's Project Infinity initiative and the hierarchical content delivery network (CDN) Comcast is developing to support it. (See SCTE Expo: MSOs Prep IPTV Push and Comcast Launches 'Project Infinity'.)
"The goal is to put a ton of video bits through a CMTS... without adding a ton of costs," a source familiar with the project says.
Comcast first introduced the concept in the form of a technical paper at the Society of Cable Telecommunications Engineers (SCTE) Conference on Emerging Technologies in April, but industry sources confirm that a product specification effort is underway, and could very well produce a super-dense "CMTS on steroids" that separates cable upstream and downstream logically, instead of physically as it's now done with the M-CMTS architecture.
Comcast hasn't revealed a product name for what's being specified, but some have referred to this logical reintegration of the CMTS as a Narrowcast Termination System (NTS) or a Next Generation Termination System (NGTS).
Sources say major CMTS and edge QAM players are all involved in the specification process, but it could be mid or late 2011 before any products from the NGAA effort are ready for deployment.
— Jeff Baumgartner, Site Editor, Cable Digital News