The national telecoms operator, BT, has today delivered an earlier than expected surprise by announcing their intention to deploy the next generation hybrid-fibre G.fast (ITU G.9701) broadband technology across the United Kingdom from 2016/17, with “most homes” told to expect speeds of ‘up to’ 500Mbps (Megabits per second) and there’s also a “premium” option for up to 1000Mbps (the premium may come via FTTP).
At present most of BT’s national deployment is dominated by their hybrid Fibre-to-the-Cabinet (FTTC) broadband technology, which delivers download speeds of up to 80Mbps by running a fibre optic cable to your local street cabinet and then using VDSL2 over the remaining / existing copper line from the cabinet to your home.
Existing FTTC is most effective for properties that exist up to 400 metres away from their street cabinet, although the service has been known to reach 2000 metres; albeit with significantly slower sub-superfast speeds (i.e. well below the Government’s definition of 24Mbps+).
By comparison G.fast works in a similar way, except that it requires significantly more radio spectrum (FTTC = 17MHz vs G.fast 17-106MHz+) and must thus operate over a much shorter run of copper cable (ideally less than 250 metres). As a result the high capacity fibre optic line has to be taken even closer to homes, usually as far as a smaller remote node or distribution point (FTTdp / FTTrN) that can be built on top of a telegraph pole, inside a street cabinet or possibly even put underground.
This extra work is costly and complex, but also means that BT doesn’t need to dig up your garden or run a new physical line into your home, which would be hugely time consuming and even more expensive. The downside is that depending upon copper lines, even a small amount, means that service speeds may be significantly slower for those at the furthest reaches of G.fast (how slow will very much depended upon BT’s chosen deployment methodology).
BT conducted a field trial of mock-up G.fast technology earlier this year (full details here and here) and on the shortest 19 metre copper line they managed to achieve aggregated speeds of around 1000Mbps (Megabits per second), which equated to 231Mbps upload and 786Mbps download. By comparison the “long” 66 metre line produced 200Mbps upload and 696Mbps download.
As part of today’s announcement BT has confirmed that their Openreach division will begin “widespread deployment” of G.fast sometime in 2016/17, but this will subject to the results of two pilots that are to be run before.
The two pilots will start this Summer 2015 in Huntingdon (Cambridgeshire) and Gosforth (Newcastle). Around 4,000 homes and businesses will be able to participate in the pilots, which will explore what speeds can be delivered using G.fast at scale.
BT is likely to deploy G.fast from various points in the network, with the pilots allowing it to assess various rollout options. It is also planning to develop a premium fibre broadband service for those residential and business customers who want even faster broadband, of up to 1Gbps.
Gavin Patterson, BT’s CEO, said:
“BT is a world leader when it comes to fibre innovation and we are excited about the next stage in our story. We believe G.fast is the key to unlocking ultrafast speeds and we are prepared to upgrade large parts of our network should the pilots prove successful. That upgrade will depend however on there continuing to be a stable regulatory environment that supports investment.
The UK is ahead of its major European neighbours when it comes to broadband and we need to stay ahead as customer demands evolve. G.fast will allow us to do that by building on the investment we have made in fibre to date. It will transform the UK broadband landscape from superfast to ultrafast in the quickest possible timeframe.”
Meanwhile BT’s FTTC dominated deployment of “superfast” (24Mbps+) capable broadband technology, with a few pockets of 330Mbps capable pure fibre optic FTTP, is continuing and its network now passes almost 22 million homes and businesses. The current roll-out forms part of the Government’s intention to make superfast speeds available to 95% of the UK by 2017.
As for the G.fast plan, its deployment is expected to complete by 2020 (assuming all goes well with the trials), although crucially we don’t yet know precisely what proportion of the UK will receive the service. It’s also worth noting that G.fast performance also suffers significantly when it has to coexist in an environment with VDSL2 (FTTC), although we won’t know what kind of impact this will have until BT has established a clear methodology for how it will deploy G.fast.
In terms of cost, G.fast isn’t cheap and might cost as much as several billion pounds to roll-out, but again this will depend upon BT’s chosen deployment methodology and how much of the UK will be covered. The operator spent around £2bn pushing FTTC out to third thirds of the UK and we anticipate that something similar may be required for G.fast, but more information is required.
The other big question is whether this roll-out will have any impact upon the deployment of Vectoring technology, which is needed to tackle the crosstalk interference issue that has been causing a performance loss of up to 20-30% on some FTTC lines.
In chatting with BT’s we’ve been told that the operator believes G.fast should be able to deliver speeds of up to 500Mbps within a decade. But crucially the operator said that the 1000Mbps premium service is “likely to be delivered” via pure fibre optic Fibre-to-the-Premises (FTTP) technology and possibly not G.fast, which wasn’t mentioned in their press update.
However BT said that it was still early days and suggested that no decision had been made on this, not least because G.fast can do 1Gbps in some circumstances and they’re “continuing to push the boundaries” of that technology.
So in other words, the “premium” service might be done via G.fast, but the current direction is for it to be achieved through an FTTP upgrade (at present FTTP can only do 330Mbps on BT’s platform).
UPDATE 20th April 2015
A new / third trial location in Wales has been announced, alongside some more details (here).