DOCSIS 3.1: Give Me MoreDOCSIS 3.1: Give Me More

'More' means greater revenue for cable operators and more -- much more -- bandwidth for customers.

Cable subscribers who aren't satisfied with bandwidth in the megabit-per-second range should take note of a technology called DOCSIS 3.1 that promises to move connections into the gigabit-per-second range.

DOCSIS (Data Over Cable Service Interface Specification) 3.1 has been updated several times since its introduction in October 2013. The DOCSIS 3.1 suite of specifications support capacities of at least 10 Gbps downstream and 1 Gbps upstream using 4096 quadrature amplitude modulation.

The speed boost comes without requiring operators to upgrade their existing cable plants, said CableLabs, a nonprofit Innovation and R&D Lab. DOCSIS 3.1 allows up to 50% more data over the same spectrum of hybrid fiber coax (HFC) networks, and uses active queue management to reduce latency. (For more information, see the Arris International paper, "Breathing New Lifespan into HFC: Tools, Techniques, and Optimizations, and the CableLabs FAQ here.)

Fiber-to-the-home (FTTH) and fiber-to-the-premises (FTTP) providers can't keep up with demand, and not all homes and businesses have access to fiber. HFC and DOCSIS 3.1 solves a huge problem for cable operators. Not only will they be able to charge more for the additional bandwidth, they'll be doing so with improved customer experiences. This will play well particularly to bandwidth-hungry telecommuters and other home workers. DOCSIS 3.1 will sort of do for cable operators what caller ID did for phone companies -- i.e., give them an additional source of revenue with very little effort.

Comcast is testing DOCSIS 3.1 using gigabit modems from Technicolor modems in an Atlanta trial. It plans other rollouts in Chicago, Detroit, and Miami.

For small and medium-sized businesses, DOCSIS 3.1 can provide an alternative to slower primary Internet services, as well as act as a better backup for those with primary fiber connections. Some of the issues with coax as a backup are the lack of speed and latency, so in some failover configurations, voice traffic is routed to cell phones or cloud-based automated attendants.

As the name implies, HFC isn't fiber end to end, and so cable operators must still deal with the limitations of copper. Copper will always remain vulnerable electrically speaking and it is still noisy. Fiber may have an optimistic future, but HFC still has conversions and it still has copper.

Even so, hats off to the cable industry because DOCSIS 3.1 is a win for operators as well as their customers, even if the win is mid-term. The cost per Mbps or Gbps is still higher over copper than fiber,and when you don't have accessible fiber, you will gladly settle for copper services.

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