CableLabs is One Step Closer to 10Gbps Full Duplex DOCSIS3.1 Broadband

Cable operators like Virgin Media (Liberty Global) are slowly gearing up to launch trials of their new DOCSIS 3.1 technology, which could push peak download speeds to 10Gbps (1Gbps upload). But now CableLabs claims to have proven the “viability” of a symmetrical 10Gbps using the same standard.

The existing Data Over Cable Service Interface Specification (DOCSIS3 / EuroDOCSIS 3.0) broadband standard still has a little bit of mileage left and indeed Virgin Media has already launched top speeds of 200Mbps for homes and 300Mbps for SME businesses. After that it may even be possible to go a bit higher, although equally they could make the jump to DOCSIS3.1.

The new Hybrid Fibre Coax (HFC) DOCSIS3.1 standard aims to deliver peak speeds of 10Gbps (Gigabits per second) by boosting the amount of radio spectrum available to it and making better use of Orthogonal Frequency Division Multiplexing (OFDM).

However even DOCSIS3.1 is currently still limited to using asymmetric Frequency Division Duplexing (FDD) or Time Division Duplexing (TDD), which leaves you with a slower upload than download speed. The holy grail is thus a fully symmetric Full Duplex system that could deliver 10Gbps in both directions and potentially also require fewer channels for the same capacity.

Now CableLabs, which created the DOCSIS standard, claims to have setup a new project that “proves the viability of full duplex communication.”

CableLabs Statement

Using a combination of Passive HFC and the self-interference cancellation and intelligent scheduling of DOCSIS 3.1 technology, CableLabs has built a solution that proves the viability of full duplex communication. Its approach significantly increases upstream data capacity in order to enable symmetric multi-Gigabit broadband data services for consumers and the enterprise.

These developments are expected to yield DOCSIS 3.1 network performance of up to 10 Gbps symmetrical on 1GHz HFC networks, with the potential for even higher performance by utilizing spectrum that is currently available for future expansion above 1 GHz.

One of the compelling attributes of a Full Duplex DOCSIS 3.1 network for the next evolution in HFC delivery is the strong foundation DOCSIS 3.1 technology provides. Our design and analysis shows that the existing Physical and MAC layer protocols in DOCSIS 3.1 technology can largely support this new symmetric service.

The evolution to a DOCSIS 3.1 Full Duplex network is an incremental evolution of DOCSIS 3.1 technology and will support both backward compatibility and coexistence with previous generations of DOCSIS network deployments.

Mind you it’s one thing to prove the viability of something and quite another to turn it into a working system that actually exists. So far the above proposed upgrade still has not even transitioned to the formal Research and Development (R&D) stage and before that they will have to spend the “next few months” doing further work to “validate and mature the technology“. But it is at least an important step in the right direction, even if you probably won’t see the fruits of this labour for a few years.