G.FAST – another lease of life for the copper infrastructure

Fast_internet-300x200Ever since I started my career in the IT and telecoms industry, there have been continuous improvements to data speed over copper infrastructure. Every development was greeted with the usual scepticism from critics, who claimed that it’s only a matter of time before fibre takes over.

However, the industry has proved time and time again that there are new ways to improve speed over copper. But what is it that drives this desire for ever higher speeds?

The changing perception of fibre

Fibre technologies have traditionally always been much more expensive than copper alternatives because they require highly technical engineers. They were perceived as being a ‘black art’ and a much more complex alternative to copper networks, which in fairness have worked extremely well since their introduction back in 1876.

However, over the last couple of decades fibre networks have become commonplace within the telecoms sector. As copper prices steadily rose on the Global Metal Exchanges, interest in fibre grew and the cheapness of glass has meant that fibre-based infrastructure is rapidly taking over. Unsurprisingly, fibre is an attractive option due to the almost limitless speeds it can achieve; today’s limitations are purely governed by the availability and cost of optical interfaces at either end of the connection.

Infrastructure

If you forget about the investment in the copper local loop and start from scratch, fibre is ideal to deliver broadband services, from the internet exchange all the way to a business’ doorstep. This is the reason why developing nations often have a far superior broadband network than many Western European nations, simply because they have started from scratch.

It is extremely difficult and expensive to replace all existing copper connections with fibre, particularly when the connection gets closer to the doorstep, and often means ripping up streets, pavements and sometimes even affecting the premises. It is also very expensive and often subject to legal wrangling and way leave consents to access privately owned land. This slows down the installation of new fibre-based services and it is clear that many superfast broadband rollouts are slower than expected.

G.FAST

copperDuring September, BT announced its trial results from a new development called ITU G – Fast Access to Subscriber Terminals or G.FAST for short. Once again it has proved everybody wrong – it can still make use of the last bit of copper to the doorstep, enabling a rapid roll out of the technology.

The first trial results at BT’s Adastral Park test facility look promising, with combined up and downlink of 1Gbs possible, achieved through a mix of both copper and fibre networks.

In reality, it is something that is not too far away from commercial availability as the standards were defined by ITU-T – the international telecom industrial body – in 2013 and ratified earlier this year, with signoff in December 2014. If anything, this signals confidence in the standard and as a result equipment suppliers are willing to commit to this technology, with some leading equipment manufacturers promising commercial availability some time during 2015.

Performance

Downstream speeds of around 800Mbps were achieved during the trials over a 19m length of copper, combined with upstream speeds of more than 200Mbps. Impressive speeds of around 700/200Mbps were also achieved over longer lines of 66m, a distance that encompasses around 80% of such connections. As well as delivering ultra-fast speeds, the technology also offers the flexibility to tailor the allocation of the total 1Gbs speed, according to the user’s needs. For businesses, this enables them to have more symmetrical speeds when used for VoIP or video conferencing; however, for more traditional uses, businesses may opt for a higher download speed and lower upload speed.

Another major benefit is the introduction of Fibre-to-the-distribution-point (FTTpd). If a business’ telephone line is pole mounted it will often feature black boxes with a fanout of radial cables to the building. If it isn’t, it will instead have manhole covers with GPO, BT or Openreach on them; these are the distribution points and they may be fibre enabled in the near future. As they are often just a stone’s throw away from a business’ premises, this enables organisations to achieve ultra-fast speeds whilst using existing traditional copper, but only for a very short distance.

FTTdp is potentially a more cost-effective and simpler solution than both FTTP and dedicated business lines, such as Ethernet, because less fibre and civil engineering is required. It also has the potential to be less disruptive for customers, given that it is likely that it could be a ‘self-install’ product with no need for home engineering visits.

Providers

From a communications perspective, it would be nice if we could have this tomorrow, but sadly the availability is still some way off. As we wait, it makes sense for businesses to investigate what is at their disposal today because connectivity prices and availability are changing for the better.