Vectoring Trials Begin as BT Look to Boost UK FTTC Broadband ISP Speeds

BTOpenreach, which helps to maintain and upgrade BT’s national telecoms network, has confirmed that the first customer trials of VDSL2 Vectoring technology (ITU-T G.993.5) are live. The new technology could deliver a significant speed boost to users of the operators existing up to 80Mbps hybrid-fibre (FTTC) superfast broadband network.

At present FTTC works by taking a fibre optic cable from the telephone exchange and all the way to your local street cabinet. After that the VDSL2 technology, which is similar to current 20-24Mbps ADSL2+ services but faster over shorter distances, is used to deliver the remaining broadband connection over existing copper lines and into your home.

Unfortunately the remaining run of copper cable is still susceptible to interference (e.g. crosstalk [XT]), especially the signal degradation that occurs over longer distances and reduces your lines potential speed. In particular one of the biggest problems for VDSL2 is far-end crosstalk (self-FEXT), which occurs when several lines effectively create interference for one another.

The solution to this is to adopt Vectoring technology, which acts a bit like those noise cancelling headphones and employs the coordination of multiple line signals in order to create a reduction of crosstalk. Some speculate that the solution could push headline FTTC speeds up to 100Mbps+ and, with the help of a few other tweaks, possibly as high as up to 200Mbps.

However BT’s Head of Access Platform Innovation, Kevin Foster, said earlier this year that “Vectoring is seen as a speed enabler rather than a speed booster“. In other words the technology is intended, at least initially, to improve existing performance rather than to raise the current headline rate of 80Mbps. It might even help those still stuck on longer copper lines.

Now Openreach has just confirmed to ISPreview.co.uk that their trial “will be monitoring the maximum speed trial lines could theoretically achieve“, although at present there are no firm plans to boost the headline speed (though this could always change next year). Meanwhile ISPreview.co.uk has also been told that BT’s first trial cabinet is live and that the remaining 5 cabinets “will become vectored in the next 2-3 weeks“.

Openreach’s UK Vectoring Trial Locations & Cabinets

* Barnet (London, England)
— Street Cabinets 26, 41 and 42

* Braintree (Essex, England)
— Street Cabinets 12, 39 and 74

Openreach expects the current trial to finish “some time” during November 2013, at which point the cabinets will return to their normal mode of operation. The operator will then begin carefully assessing the results before deciding upon the technologies future and any further tests.

But there are a few drawbacks to Vectoring technology. Firstly, it will cost money to upgrade your street cabinet and, in order to be effective, it ideally needs to be applied across all of the cabinets FTTC lines. The last point means that a Vectoring upgrade could take slightly longer to deploy and it might also run into compatibility problems with Sub Loop Unbundled (SLU) ISPs that use different kit (possibly making the technology unusable in a small number of areas – Ofcom are currently reviewing this).

Otherwise the majority of end-users (broadband ISP customers) won’t need to make any changes at their end, although some might require a replacement VDSL modem or a special firmware update. All being well we could see the first commercial Vectoring deployment in 2014 but that decision has yet to be made.