But some observers worry that the 'fibre by degrees' approach implicit in VDSL2 deployments fragments the market and will make a big push into fibre even more difficult to execute.

VDSL or 'hybrid' copper/fibre, alongside fibre, are together providing the growth in the broadband market says broadband consultancy Point Topic. Subscriptions to PLOD (PLain Old DSL) - both asymmetric (ADSL) and symmetric (SDSL) versions - are now shrinking in the international market according to a report it released last week. Point Topic now sees pure fibre and 'hybrid' fibre/copper (VDSL) technologies picking up the reins to drive broadband growth.

"End to end copper" (copper right to the exchange or central office running A or SDSL) will now make up a diminishing proportion of the broadband market, but instead of replacing it with fibre, many operators are determined to take a more granular (and they claim, economically sane) approach by matching the sort of architecture put in place by cable operators with their fibre hybrid coax deployments. These networks run fibre out to the local node and then use copper (in the case of cable networks it was coaxial cable - in the case of telecoms it is unshielded twisted pairs) to effect the final drop to the user's premises. For telcos this approach is way more economical because they can re-use the copper already built in to people's houses, while the new technology can drive the short run of copper at much faster speeds.

Most recently Alcatel-Lucent in particular has championed vectored VDSL2 and says it's now shipped one million VDSL2 vectoring lines to 11 service providers since launching the technology just over a year ago in late 2011. VDSL2 uses noise-cancelling technology to bump short run (400 metres) speeds up to 100 Mbps downstream, easily matching the low-end of the FTTH market at a fraction of the cost of pure fibre.

In Europe Alcatel-Lucent has deployed its VDSL2 vectoring systems commercially with Telekom Austria and Belgacom and says it is involved in another 40 trials trials globally including China Telecom, TDC Denmark and P&T Luxembourg. It's claimed that fibre and hybrid fibre connections now account for over 20 per cent of the world’s fixed broadband lines and are expected to grow by more than 26 per cent in 2012.

As such vectored VDSL2 is being deployed as an alternative to fibre to the Home (FTTH), although operators using the technology are usually quick to claim that the investment is just a stop-gap - FTTH will be along in the long term, they say.

That may be, but there's no doubt that vectoring is a thorn in the side to those who are pushing for fibre - in danger of being another excuse, it seems to them, for incumbents and national governments to spend a few more years sitting on their hands and doing nothing about fibre penetration. They can always point to vectored VDSL and mumble about market forces doing their job.

The problem is one of scale. If a proportion of early adopter broadband users take up VDSL2 when it's offered then that starts to ruin the economics for blanket fibre deployment later on, since your prime targets are already sitting pretty.

According to fibre expert and TelecomTV contributor, Benoit Felten, BT's recent introduction of fibre to the node and VDSL speeds to the home, came with an ability to upgrade to fibre for individuals who wanted greater than VDSL speeds. One little catch: the upgraders would not, by definition, be sharing the cost of mass deployment.

"It's an absurd concept," says Benoit.

"First because the costs of FTTP deployment that are commonly considered (say around €1000 per home in dense urban areas) are mass deployment costs. These costs can be met when you send teams on the field to connect every home. If you send teams on the field to connect one home, the costs are much much higher.

"Secondly, and very ironically, both BT and the Australian NBN chose point-to-multipoint architectures. That means that if a customer was to ask for an FTTP connection in a given area, the whole active equipment chain from the customer’s ONT to the splitter to the OLT would have to be activated for a single customer. The costs of that are absolutely prohibitive."