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Is G.fast the answer to the UK’s fibre vs copper debate?

At Broadband World Forum in London there was much talk of G.fast technology – but is it really the broadband panacea operators such as BT make it out to be?

Smiling as if Christmas had come early, BT’s managing director of strategy, service and operations Mike Galvin took to the stage – twenty five minutes late – to deliver his address on transforming the UK broadband landscape from superfast to ultrafast.

If there was one exhibitor riding high at this year’s Broadband World Forum – an exposition of network transmission technology, hosted at London’s ExCEL for the first time – it was BT. Indeed, in recent weeks Ofcom’s communications market review seems to have had the effect of galvanising the operator into a non-stop tub-thumping session.

Much of BT’s newfound enthusiasm stems from the developments around the G.fast standard, which is what Galvin was on stage to talk about, and which BT says holds the key to achieving ultrafast broadband for most people in the UK, and allows it to sweat its copper network for far longer than anybody expected.

Galvin headlined his talk with the announcement that BT and Alcatel-Lucent had achieved speeds of 5Gbps in laboratory conditions, over a single 35m copper pair, some of the fastest speeds yet achieved using the technology, which BT is currently road-testing in the wild in Cambridgeshire and Newcastle.

What is G.fast?

G.fast is a new digital subscriber line (DSL) standard for local loops of under 500m, which targets performance of between 150Mbps and 1Gbps depending on distance from the distribution point, whether that be a fibre cabinet or a remote node.

At a very basic level, it works by expanding the frequency range used by broadband signals. Whereas the second generation very-high bit-rate DSL (VDSL2) technology, currently in widespread use at the core of the Openreach fibre-to-the-cabinet (FTTC) service, uses 17MHz and 30MHz, G.fast widens this down to 106MHz and up to 212MHz. With G.fast, communications services providers (CSPs) can offer more bandwidth on the line and, therefore, faster services.

Do we really need FTTP yet?

Much of the controversy around the UK’s broadband roll-out has focused on what many justifiably see as BT’s lack of ambition in continuing to commit to copper when gigabit speeds that, incidentally, go way beyond what G.fast can currently deliver, are available in the UK today on a fibre-to-the-premises (FTTP) connection.

Described by some as a stepping stone to FTTP, G.fast is attractive to players such as BT because it means that Openreach needs to do very little to upgrade its existing network in support.

“We can build G.fast right on top of our fibre cabinet infrastructure – this makes a huge difference, because it gives us low-cost deployment options with hybrid G.fast and VDSL2,” said Galvin.

The advent of G.fast enables BT to continue to use its copper lines for as long as gigabit broadband is considered satisfactory, and allows it to kick the need for it to invest in FTTP everywhere into the long grass for several more years.

This view is backed up by statistics produced by the Broadband Stakeholder Group (BSG). Speaking at the event, the BSG’s chair Richard Hooper said: “Politicians are obsessed with 1Gbps minimum, there’s almost a virility competition. However, we built a model and nobody has yet demolished it, which gives you an indication of the speeds people want.

“In 2023,” said Hooper, “the median household will need 19Mbps. The top 1% will need between 35 and 39Mbps. People are willing to pay for much higher speeds and that’s fine, but our research shows that people need much less.”

If these statistics are true, and Hooper declared himself open to having his sandcastle kicked over, the financial arguments for using a low-cost system such as G.fast to deliver more than the median demand suddenly become compelling.

Seizing the opportunity

BT has jumped on the potential of G.fast, and in its recently-announced charter, Openreach committed to bringing speeds of 300-500Mbps to 10 million homes and businesses using G.fast, in a roll-out that will begin in 2016.

In his address, Galvin described the technology as a “game-changer”, and said its field trials matched the 300Mbps speeds obtained during pre-trial lab tests.

Kouroush Amiri, vice-president of marketing at Ikanos – whose talk on pushing the boundaries of G.fast was the overrunning cause of Galvin’s tardiness on the ExCEL stage – said speeds of 300Mbps were of great interest to telecoms firms, but his CSP customers were already asking how they could get to a gigabit.

“Hitting that speed is very important to telcos, and they also want to address a larger portion of their network, from 100m and further out,” he said.

“G.fast is at the start of its lifecycle and, with further developments – such as increasing the number of bits per tone and lowering the noise floor – we could deliver 500Mbps. That’s not an engineer’s fantasy, this could be reality,” said Galvin.

Mark Fishburn, strategic marketing director of the Broadband Forum – which is currently hard at work developing future standards for G.fast technology – said that for firms like BT, G.fast opened up other possibilities.

“Certainly the ability to deliver higher bandwidth is important, but it is not the only thing. G.fast brings new business models and markets without new investments,” he explained. “It provides a platform for over-the-top (OTT) services and new kinds of apps.”

Well, is it the answer?

No. Britain needs FTTP. In a perfect world, Openreach would have long since opened its chequebook and got the government funding to deliver it. Universal FTTP must remain the goal. The dawn of G.fast should have no impact on the pressure that campaign groups put on BT and Openreach.

However, this is not a perfect world and the government has no money. In these austere times BT is right to seize on the opportunity to do a little better with much less, instead of doing the very best for much more. Quite simply, this is an argument over economics, not speed.

“G.fast will provide a fantastic service for the vast majority of customers, but it is only one of a number of options,” said Galvin. “We are developing premium on-demand fibre services to sit alongside VDSL2 and G.fast, and we will in future offer an upgrade path to direct fibre connectivity as well.”

Ronan Kelly, Adtran EMEA CTO, added that, when used in combination with other broadband technologies, G.fast will give providers “more opportunity to build a best-in-class solution from their toolkit”, and deliver the optimal broadband technology for a given situation.

So as one element of a wider roll-out that includes FTTC, FTTP, microwave links, fibre-to-the-remote node (FTTrn), and even satellite, G.fast makes a good deal of sense. It can begin to take the UK national network towards the ultrafast speeds consumers and businesses demand and deserve.

It does not end the debate over fibre and copper – because this is a debate that fibre will win – but when the goal is to go faster, G.fast has much to offer, and should not be written off just because it uses copper lines.

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How will the G.fast box be powered? There will be quite a lot of energy needed to power the equipment for the 10 million homes to which Openreach is committed to bringing 300-500 Mbps by 2016. If the equipment is in the cabinet then this is only for those within reach of the cabinet- what happens to the long line rural dwellers this time? If the rural dwellers get their G.fast on top of poles where does the power come from please Openreach?
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Gfast also depends on the quality of the copper. Which is cheaper? Upgrading 40 and 50 year old copper (and/or aluminium/hybrid) pairs or replacing them with fibre?
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NO BT we need fttp. it isn't just about bandwidth, it's also about latency.

facetime, skype, voip, GAMING, are all time sensitive.

using 50 year old copper wire to deliver future speeds is a problem. BT & Virgin are being cheap and are becoming as bad as companies like Time Warner & Comcast, together they are stopping the progression of the internet. At least america have other full fttp companies, we're stuck with these losers
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There are FTTP companies installing networks in the UK, not dependent on the copper infrastructure. If public money went to support these and more like them, and the government freely allowed access to dark fibre, and actively encouraged their growth instead of repeating BT nonsense and condoning OVERBUILDING (where there are already subscribers on fibre networks) we could ultimately genuinely claim to be 'digital Britain'. A target of 10 Mpbs is not enough David Cameron. NOT ENOUGH.
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If I put racing tires on my vintage VW Microbus, I still have a VW Microbus. With the attendant costs of updating and tweaking, it's probably sane/safer/smarter to run fiber.
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