Long-reach VDSL2 has potential for rural NZ

Communications Day reports BT is testing a long-reach version of VDSL2 in rural areas. The story first appeared at ISP Review.

Long-reach VDSL2 could be ideal for those parts of New Zealand falling between the urban UFB fibre-based network and the fixed wireless broadband delivered by Rural Broadband Initiative towers.

At the moment the government is looking at tenders from companies aiming to reach some of these areas through the second phase of its UFB project.

Extending copper into the wop wops with VDSL2

VDSL2 already extends the broadband capacity of New Zealand’s copper phone networks, especially in places where fibre is not yet available. Typically customers with VDSL connections enjoy fibre-like speeds over copper.

The problem with conventional VDSL is that its performance drops off over distance. If you live near an exchange or a fibre-fed roadside cabinet you might see speeds in excess of 40Mbps. By the time you are a kilometre from the connection point that speed might drop to half the maximum.

The long-reach VDSL2 on trial in the UK gets around that. Communications Day quotes BT saying it “should deliver more than twice the data speeds of existing broadband networks over a distance of up to 2km.”

“LR-VDSL exploits existing features currently defined in ITU-T Recommendations G.993.2 and G.993.5 to enable fibre-to-the-cabinet VDSL2 lines with a D-side length in excess of 1.25km (0.5mm diameter copper) to be uplifted to give a higher downstream rate".

BT says its proof of concept trial in April showed that a copper line delivering 9Mbps could be “uplifted” to 24Mbps with the technology.

It seems VDSL2 isn’t suitable for all copper lines, but BT says the technology in the long-reach version could manage 40Mbps down and 10Mbps up over a distance of up to 2 kilometres.

Chorus’ cabinet network already extends to most settlements throughout New Zealand, even small places. If the reach of each cabinet can be extended using long-reach VSDL2 there will be few communities not served by decent broadband services delivered over copper.