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Cable Show 2013: CTOs Say DOCSIS 3.1 Will Save Cable’s Upstream

OFDM Will Make Spectrum 50% More Efficient 6/10/2013 12:07 PM Eastern

Washington — Cable operators said the emerging DOCSIS 3.1 specifications will save them time and money by leveraging their existing upstream spectrum and avoiding more costly bandwidth-enhancing alternatives. 

DOCSIS 3.1 and its use of orthogonal frequency-division multiplexing (OFDM) “is a godsend in the upstream,” Comcast executive vice president and chief technology officer Tony Werner said Monday during a Cable Show panel that covered a broad range of technology topics. 

OFDM, a technology that’s already popular in the wireless world and tagged for the new DOCSIS 3.1 specs, will give cable access to a modulation scheme that’s expected to make existing spectrum about 50% more efficient. That could help cable operators avoid an operationally tricky “mid-split” that would widen the current upstream spectrum range from today’s 5 Megahertz to 42 MHz.  

 “I don’t think we’ll have to widen the upstream,” Mike LaJoie, Time Warner Cable’s executive vice president and chief technology officer, said. He said cable continues to develop tools that enable MSOs to adapt the network and stay ahead of potential bandwidth crunches. 

Execs also talked about when they expect to deploy DOCSIS 3.1, a platform that has designs on supporting downstream capacities of 10 Gigabits per second and upstream speeds up to 1 Gbps. CableLabs is expected to complete the specs this year. 

Werner said he sees DOCSIS 3.1 trials starting in 2014, and expects commercially-ready products becoming available by late 2014 or early 2015. 

Comcast, he said, will start purchasing DOCSIS 3.1 modems as soon as it makes financial sense, and, as a future-proofing measure, expects to deploy those devices even before the networks are upgraded for the new platform. The first D3.1 modems are expected to be hybrid versions that also support DOCSIS 3.0. 

 “As soon as we can get modems at the right [cost] delta, we’ll be buying DOCSIS 3.1 modems,” Werner said. He wouldn’t say what that magical price point is, but “if they’re twice as much, you have a hard-time future proofing.” 

He also liked that DOCSIS 3.1’s use of OFDM will make the service more resilient to interference with Long Term Evolution (LTE) signals. “It’s an evolution that has a lot to like about it.” 

Cox Communications has not identified when it will support DOCSIS 3.1, but company EVP and chief technology officer Kevin Hart said the MSO is already starting to do the kind of network preparation required to “free up channels to enable this capability.” 

 “We’re all excited about doing more with what we have,” said Yvette Kanouff, executive vice president of technology at Cablevision Systems. 

DOCSIS 3.1 is also viewed by some as a way for cable operators to counter the threat of 1 Gig services from Google Fiber and other ISPs. But cable operators continue to downplay that threat, noting that the highest speed tiers offered today tend to be the lowest penetrated. 

 “There hasn’t been demonstrated appetite for it,” LaJoie said of 1-Gbps residential speed tiers. DOCSIS 3.0 tiers that offer 100 Mbps or more “are not very deeply penetrated.” 

But panelists also stressed that cable will be prepared when 1 Gig speeds to the home are needed.

 

 

 

September