Virgin Media Parent Eyes Future 10Gbps and DOCSIS 4 Upgrade

Liberty Global, the parent of cable broadband ISP Virgin Media UK and various other European operators, has informed shareholders that they’ll be starting work on 10Gbps broadband connectivity “pretty quickly” by using a mix of a future DOCSIS 4.0 upgrades and more Fibre-to-the-Premises (FTTP) technology.

At present Virgin Media’s existing network is dominated by Hybrid Fibre Coax (HFC) technology, as well as some FTTP via Radio Frequency over Glass (RFoG). Both sides of their network are currently in the process of being upgraded to support the DOCSIS 3.1 standard (due to finish by the end of 2021), albeit at present only on the downstream side (it’ll be added to upstream in the near future, which will bring more speed and latency improvements).

The upgrade to D3.1 is a relatively straightforward one that largely improves performance by utilising enhancements to Orthogonal Frequency Division Multiplexing (OFDM), which can encode data by using multiple carrier frequencies, and boosting the amount of radio spectrum available for data transfer up to 200MHz; plus, a lot of smaller changes under the hood.

In theory a fully D3.1 upgraded network should be able to handle a peak theoretical download speed of up to 10Gbps and uploads of around 1.5Gbps, although feeding all of that with enough capacity and ensuring all of your customers have supporting kit (routers) will take time. Equally Virgin are likely to consider demand and boost speeds gradually, much as they’ve always done (hence first D3.1 package is 1Gbps, but they’ve tested to 2.2Gbps).

However, FTTP networks are easily able to keep pace with HFC, which is one of the reasons why CableLab’s has already developed DOCSIS 4.0 (formerly Full Duplex D3.1). The future upgrade boosts available spectrum up to 1.8GHz and makes further improvements to QAM, among other things. The result is a network that retains a peak downstream of 10Gbps, but pushes upstream to 6Gbps and gives even better latency.

The good news is that Liberty Global may be moving on to develop D4.0 sooner than expected, at least that’s what their group boss said during last week’s post-results media call.

Mike Fries, CEO of Liberty Global, said:

“We know our networks are valuable today well beyond where they’re being valued and for all kinds of reasons that make good sense. The path to continued speed enhancement in our fixed networks, you’ve got multiple paths. But today we’re getting the most out of 3.1, which again we’ve already trialled 2.2 gig speeds with 3.1. That’s something we can do if we choose to.

But we’re really focused on 10G and, to be honest with you, when I mentioned 1 gig five or six years ago everybody was like.. what the heck is that needed for. Trust me when I say that the 10 gig conversation will be starting and will be starting pretty quickly.

When we look at our networks, we’ve got a couple of ways to get there with DOCSIS 4.0, where we would fall right in line with the US operators, Charter and Comcast, both of whom would be pursuing a strategy like that. And we could also use FTTP, CSPON, where we have, we think, the economics to support that kind of roadmap to 10G.

So stay tuned, lots to talk about there and as you point out lots of cool things with faster speed and lower latency, lots of cool things we can do both with our fixed and mobile networks.

At this point a small reality check may be needed because D4.0 would not be a simple upgrade in the UK, at least in that sense it’s not comparable to the D3.1 deployment. Lest we also forget that Liberty Global started talking about D3.1 many years before it first began to go live on Virgin Media. Suffice to say that we’re well into the usual “take with a pinch of salt” territory.

On the one hand D4.0 via HFC would be cheaper than placing their existing network with FTTP, which is why they’ll probably do it.. eventually. But upgrading their HFC D3.1 network to D4.0 may also require node + 0 (i.e. deeper fibre nodes closer to homes – very expensive) in order to get the full benefit, as well as the complete replacement of tap banks, splitters, isolators etc. All of this would take a fair amount of time to deploy.

Suffice to say that we can’t see D4.0 happening in the UK for a good few years’ yet. The operator will most likely want to get some mileage out of the DOCSIS 3.1 standard first. Happily D3.1 does have plenty of mileage left to give, particularly in terms of upstream improvements and latency.