Cable Still Counting on DOCSIS But...

While more cable operators are flirting with fiber-to-the-home (FTTH) builds more than ever before, most MSOs are still betting on tried-and-true DOCSIS technology to deliver gigabit services in the emerging ultra-broadband market, at least in the early going.

In recent months, such larger North American MSOs as Comcast Corp. (Nasdaq: CMCSA, CMCSK), Mediacom Communications Corp. and WideOpenWest Holdings LLC (WOW) have either launched or announced plans to launch gigabit services in several markets using the newfangled DOCSIS 3.1 technology. So have such midsized and smaller cable players as Midcontinent Communications (Midco) and Atlantic Broadband . (See Slow Roll Builds for DOCSIS 3.1.)

Similarly, in Europe, such major cable players as Liberty Global Inc. (Nasdaq: LBTY) in the UK, Altice in France, VOO in Belgium, DNA in Finland and TDC in Denmark have committed to deploying DOCSIS 3.1 over the next year. And other MSOs on the continent will likely follow suit.

Why? Because DOCSIS 3.1 can enable cable providers to offer downstream speeds as fast as 10 Gbit/s and upstream speeds as high as 2 Gbit/s over their hybrid fiber-coax (HFC) networks, if they carry out all the necessary upgrades. While FTTH networks can also deliver multi-gigabit speeds, and in much more symmetrical fashion, most cable operators would still rather tinker with their existing HFC plant than make the more radical, and seemingly more costly, switch to all-fiber lines.

Plus, with the prospect of CableLabs developing the even more newfangled Full Duplex DOCSIS spec over the next few years, cable operators can anticipate even faster, and much more symmetrical, data transmission speeds coming their way. That proposed spec, which could take effect in as little as two to three years, will allow operators to offer upload and download speeds as high as 10 Gbit/s. (See Full Duplex Is a Go; Cable Aims for 10 Gig.)

Yet, while they still embrace their DOCSIS devices, cable operators are definitely hedging their bets about gigabit alternatives. At a European forum on DOCSIS 3.1 staged by Huawei Technologies Co. Ltd. at the ANGA COM show in June, about two thirds of the respondents, or 66%, said they believe that a converged cable architecture of DOCSIS 3.1 and FTTH would be the best way to deliver gigabit service.

While clearly enthused about DOCSIS 3.1, cable operators also recognize that they face plenty of challenges in deploying the new spec. When asked to name the biggest challenges during the ANGA COM forum, nearly half cited the HFC network upgrades that may be needed, including changing amps, splitting nodes and switching RF optics. Exactly one third said there's not enough spectrum available to deploy D3.1. And nearly one third said operational support systems (OSS) and maintenance require new thinking. (See DOCSIS 3.1 Dominates ANGA COM.)

So while DOCSIS may still rule the cable roost, it may no longer dominate it like before. Instead, we will likely see more and more operators rely on DOCSIS 3.1 or Full Duplex in some markets and FTTH in others, depending upon the costs, plant conditions and other circumstances. We may even see cable providers deploy such seemingly telco-specific technologies as G.fast as they seek new, more cost-efficient way to wire apartment buildings and other multiple dwellings for speedy broadband service.

"We have to do both DOCSIS 3.1 and PON," said Ken Paker, CTO and vice president of Network Services for TDS Telecom , a midsized provider that operates both HFC and FFTH networks, speaking at an industry conference earlier this year. "I don't see a world where you can just do one or the other… We can never say no to any particular technology."

— Alan Breznick, Cable/Video Practice Leader, Light Reading