NEW ORLEANS – A standing-room only crowd turned out Tuesday at SCTE Cable-Tec Expo for a DOCSIS 3.1 workshop featuring Jorge Salinger, vice president of access architecture at Comcast.
Salinger is a pioneer in CCAP architecture and on Tuesday he was talking about the move toward deploying DOCSIS 3.1.
“We want to be able to deploy gigabit service as broadly and as quickly as we can,” Salinger said.
He said field activities with the standard are beginning this year at Comcast and deployments will begin next year. Right now, Comcast is developing on a plan to deploy DOCSIS 3.1 in all types of HFC systems and working on freeing up the additional needed spectrum by reclaiming MPEG-2 HD.
In a nutshell, Salinger said progress for the DOCSIS 3.1 spec has moved on to coordinating development between silicon providers, operators and vendors.
Though actual DOCSIS 3.1 deployments are still fairly far off on the horizon, hype around the emerging standard is high—as demonstrated by the capacity crowd gathered to here Salinger talk about it. Salinger admitted to the audience that Comcast is helping contribute to the hype around multi-gig by already offering 2 Gbps service.
But the speed at which the DOCSIS 3.1 hype is increasing correlates with how much faster that spec was developed compared with the time it took to design DOCSIS 3.0, Salinger said.
According to Salinger, one of the main changes made in the jump from DOCSIS 3.0 was a change in forward error correction, moving from LDPC instead of RS. The change has enabled higher modulation orders (i.e. 512/1K in the upstream) and up to 50 percent more bits/sec/Hz.
Comcast is also seeing bigger spectrum blocks available. Salinger said the operator is now leveraging two 192 MHz blocks for downstream and two 96 MHz blocks for upstream.
Comcast is also adding support for multiple modulation profiles (MMP). Salinger said MMP allows them to offer options to cable modems, particularly those that can support higher than 256 QAM (up to 4096 QAM).
Despite all the advancements, there’s still the question of when critical mass will be hit for adoption of DOCSIS 3.1 equipment and offer operators reasonable ROI and rationale for allocating resources.
Salinger couldn’t offer a specific percentage in terms of how many subscribers need to have DOCSIS 3.1 CPE before moving forward with large-scale deployments. But he did talk about a strategy Comcast is using early on, in which the company identifies the highest volume users on its network and preemptively sets them up with DOCSIS 3.1 equipment.
