NBN Co ready to build 10Tbps core

Completion of 12 weeks of negotiations with Telstra has given NBN Co access to enough dark fibre to allow it to proceed with constructing a core transit network that will use 100Gbps fibre technology to link NBN points of interconnection (PoIs) with up to 10 terabits per second (Tbps) of aggregate capacity.

(Credit: David Braue/ZDNet Australia)

Speaking at the CommsDay Summit in Melbourne, NBN Co CEO Mike Quigley said that the completion of the network design would pave the way for construction to commence on Transit Release 1. This release is the first of four transit-network releases, each of which will provide critical connections linking NBN fibre access nodes (FANs), satellite base stations and LTE wireless base stations with the 121 NBN PoIs spread across the country.

The current release will link 125 FANs with 29 PoIs using 149 different Telstra dark fibre links spanning a total of 5254km. Each strand of fibre will use dense wavelength division multiplexing (DWDM) technology to carry data over 96 separate wavelengths at 100Gbps per wavelength — providing aggregate capacity of just under 10Tbps.

"We believe that should be sufficient," Quigley deadpanned as he updated attendees at the industry event on the company's progress to date.

Demand for that bandwidth is increasing dramatically, Quigley added, citing recent Australian Bureau of Statistics figures that showed the volume of data downloaded over fixed internet connections has exploded in the past year — from 174,665 terabytes over the three months to June 2010, to 254,947 terabytes in the three months to June 2011. That's a 45.9 per cent increase, compared with just a 12.7 per cent increase in the volume of data downloaded to mobile broadband connections.

While those figures might seem to contradict figures showing an explosion in mobile broadband adoption — Australia's 4.786m mobile broadband customers surpassed its 4.493m base of DSL subscribers for the first time in June — they reflect a growing recognition that mobile networks alone aren't going to be able to shoulder massive increases in data usage.

Instead, said Quigley, the explosion in fixed-data usage reflects growing usage of smartphones and Apple iPads at home, where they connect to fast in-home Wi-Fi services that get online using conventional fixed services.

"Data in Australia says around 90 per cent of all data is on fixed networks, but one of the largest vendors in the world has predicted that by 2016, the amount of data carried on mobile networks as a percentage of all data will be just 0.5 per cent," Quigley said. "NBN Co are very keen on mobile services, because our belief is that the two networks are quite complementary."

The new transit network will provide more than enough headroom to support the roll-out of NBN services to Australian households, which will get a massive boost when NBN Co soon releases its much-anticipated network coverage maps that highlight its detailed roll-out plans. Quigley was keeping quiet on the location of these services, but they will build on the transit network deal announced today.

He was more open, however, about the potential for the new transit network to support NBN's goal of open access across technologies. A total of 27 retail service providers (RSPs) currently signed up to provide NBN services, of which 12 have successfully "on-boarded", or correctly configured their services to interface with NBN Co's.

Of those, Quigley said, four were previously satellite providers that have now been on-boarded to provide fibre services, as well. This is a result of the NBN core design that uses a common PoI infrastructure regardless of the access technology used, he said; "They discovered that in providing a satellite service on the NBN, because all the interfaces and systems are exactly the same, it really doesn't matter to them whether they are providing fibre services, fixed wireless or satellite services."

"It's the same interfaces," he continued, "and [RSPs] could go after a customer on any technology within that footprint; they're all connected to the same PoI and in the same way. So, the model seems to be working the way we had hoped the model would work."