Is fibre really close to capacity?

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The internet already accounts for at least 8% of the UK's energy requirements, thanks to devices from PCs to TVs to phones - and even before the Internet of Things becomes a serious reality, demand continues to rise.

It's thought that if usage continues at its current rate, the internet could even require the equivalent of the UK's entire power supply within 20 years.

At the same time, the amount of data we're sending and receiving via fibre and cable is fast approaching the maximum those networks can handle.

'Radical change' needed

So a team lead by Aston University's Professor Andrew Ellis is looking into ways to boost bandwidth while also reducing energy consumption.

Professor Ellis says that unless there are "radical" changes to the technology, it's likely that the UK could see bandwidth rationing or prices rising significantly to cover the cost of laying more cables.

Speaking to several Sunday papers, he explained that the time lag between technology being developed in research labs and being rolled out to us was about eight years.

Previously, capacity has doubled roughly every two years, and it's therefore been able to keep up with, if not always ahead of, demand.

But there are signs that not much more data can be squeezed into one fibre.

Increases in bandwidth have largely been made possible by increasing the optical intensity at the core of the fibre optic cables.

The light signals being sent down the cables are now one million times more intense than sunlight before it can be filtered by the Earth's atmosphere, according to Professor Ellis - and that kind of intensity introduces significant distortion.

"It is this distortion which limits the amount of data which can be transmitted, leading to capacity crunch," he says.

Basically, we can keep sending as much data as we're sending now, but not much more - and in an increasingly connected world, it's unlikely we're going to be able to stick to that kind of limit.

Mobile technology

So the Petabit Energy Aware Capacity Enhancement project (PEACE) is looking into other ways to boost bandwidth, using a combination of analogue, digital and optical signal processing.

They believe the right balance of the three technologies could enable the transmission of enough data to support one million mobile phones, while cutting the amount of power required by half.

Singled out for mention in the project's grant application is adapting some of the technology and techniques used by mobile phones to make the most of the available spectrum.

While PEACE's concept is far more complicated, mobile technology is already helping carry the strain in some parts of the country - often the smaller, more remote, less commercially competitive, locations.

Some such areas have benefited from superfast fibre projects - but others have been given a boost by the arrival of both 4G and 3G mobile broadband.

Dark fibre

BT are one of PEACE's project partners, which makes sense when we consider that they're the UK's universal telecoms provider and effectively control access to both the ADSL and fibre networks used by almost every other ISP.

There's long been a battle to gain access to those networks, particularly the fibre infrastructure built and maintained by Openreach, which is part of the BT Group.

Most recently, Sky, TalkTalk and Vodafone have called for Openreach to become a completely separate entity, saying that BT have so much control of the network it's easy for them to dominate the market.

The rival companies say improved access to the infrastructure would give them greater incentive to invest in future technology, and improve competition.

Of particular interest to them at the moment is the "dark fibre" network - the cables laid in anticipation of future expansion.

As mentioned, one of the stopgap solutions suggested is laying even more cables to cope - but even BT's head of optical research Andrew Lord says that's not economically viable, and besides it would further increase power consumption.

Data transfer alone uses around 2% of a developed nation's electricity - and every increase in speed requires more power as well.

But while finding the extra energy needed to keep the network running may be an issue, BT say there is at least plenty of capacity for some time to come - quite possibly banking on their dark fibre network.

Meeting targets and beyond

In January the National Audit Office said the rollout of superfast broadband was a good six months ahead of schedule, which should mean 95% coverage by the end of 2017 is more than possible.

It would be deeply frustrating to everyone, then, if the infrastructure is put in place on time only to grind to a congested halt a few years later - or for access to the superfast world to be rationed because there isn't enough energy to keep everything running.

It sounds like an extreme nightmare - which is why Professor Ellis is co-chairing a two day meeting at the Royal Society next week, looking into the likelihood of the "capacity crunch" and how to avoid it.