Symmetric 10Gbps DOCSIS 3.1 Cable Broadband Trials to Begin in 2017

The Chief Strategy Officer for CableLabs, Ike Elliott, has revealed that the first trials of 10Gbps (Gigabits per second) capable Full Duplex DOCSIS 3.1 technology, which could eventually be deployed by Hybrid Fibre Coax (HFC) based cable networks like Virgin Media, will begin next year.

At present Virgin Media’s network is predominantly based off EuroDOCSIS 3 (Data Over Cable Service Interface Specification) technology, which currently offers top consumer accessible download speeds of up to 300Mbps. However, towards the end of 2017 we’re expecting them to start the commercial deployment of their next generation DOCSIS 3.1 technology (details).

The new DOCSIS 3.1 standard can in theory deliver peak network speeds of 10Gbps download and 1Gbps upload, yet the holy grail of HFC networks is to achieve a Full Duplex symmetrical transmission (i.e. 10Gbps for both upload and download). A lot of work has gone into designing this during 2016 (here and here) and the first trials may now occur sooner than expected.

Ike Elliott said (Light Reading):

“[Full Duplex is] something that’s in the labs right now. We’re working with the vendor community in defining specifications on it, and we really expect to see some trials on that within about a year.

It requires getting [fibre optic cables] all the way to the last active [component] in the network. There’s a big infrastructure investment to make… so [Full Duplex is] not going to be available across a broad footprint on day one.”

As hinted above, there are a lot of potential challenges with deploying Full Duplex DOCSIS 3.1 into the wild, not least in terms of its stiff power requirements and the need for a deeper roll-out of fibre optic infrastructure into the HFC network. In that sense we don’t expect to see Virgin Media deploying Full Duplex around the UK for a long time (commercial hardware may not even be ready until 2018/19).

Luckily consumers don’t need multi-Gigabit speeds just yet and thus Full Duplex is, for now at least, arguably more about meeting expectations in the business market. Not to mention that it will take a fair few years before cable operators’ have learnt to maximise the basic DOCSIS 3.1 standard, let alone engage in the expensive challenges of going Full Duplex.

On top of that commercial cable operators will always seek to extract the most value out of any new technology, which tends to equate to gradual speed boosts over a period of years. Virgin Media did the same with its current network, which is only now reaching into “ultrafast” (300Mbps+ by Ofcom’s definition) territory for residential connections, despite having had that capability for awhile.

Cable operators’ also have the challenge of needing to ensure that their network capacity and CPE kit (consumer routers) can keep up with such enhancements, which is another reason why they don’t jump right to the fastest speeds. We’d expect more of the same from DOCSIS 3.1’s roll-out, which will initially offer download speeds that sit well below the dizzy heights of 10Gbps.

Virgin will no doubt set their future service speeds so as to maintain a modest lead over BT’s new G.fast technology, which will initially roll-out next year (H2 2017) as a 300Mbps capable product and by 2025 this could reach 500Mbps. But G.fast speeds will be considerably less reliable than Virgin’s DOCSIS 3.1 setup and the latter may only need a year to reach around 60% of the UK at very little cost, while G.fast will take several years and cost many times more.

In other words, vanilla DOCSIS 3.1 should do just fine for many years to come, but it’s good to know that Full Duplex may eventually be an option if needed.

Side-note: We should point out that Virgin Media’s on-going £3bn Project Lightning network expansion, which aims to cover around 60-65% of UK homes and businesses by the end of 2019, includes about 2 million premises that will be covered via Fibre-to-the-Premise (FTTP) technology (this maintains compatibility with DOCSIS by using Radio Frequency over Glass).