Potentially boosting fibre to the home speeds 100-fold, NBN's latest fibre trials also promise a backend overhaul to ease traffic jams across the entire network.

While the switch to the Multi-Technology Mix has fragmented the nationwide rollout, NBN is looking to the future with plans to upgrade several of the broadband technologies used to reach Australian homes and businesses. Those with fibre running all the way to the premises still look destined to enjoy some of the fastest speeds, with Next-Generation Passive Optical Network 2 (NG-PON2) fibre trials underway but no firm commitment as to if or when the technology will be introduced in Australia.

NBN's current GPON fibre technology delivers up to 2.5Gbps download speeds over a single fibre strand, with 1Gbps uploads. As a wholesaler NBN already offers 1Gbps fibre to the premises download speeds but Retail Service Providers (RSPs) such as Telstra and Optus are yet to embrace them and only offer 100Mbps consumer plans.

The next generation XGS-PON fibre technology can hit speeds of 10/10 Gbps over the same fibre strand but NBN is already trialling NG-PON2 which quadruples the speeds of XGS-PON by sending multiple wavelengths of light down a single strand of fibre – a technique known as Time and Wavelength Division Multiplexing (TWDM).

A recent NBN demonstration in Melbourne, in conjunction with Nokia, achieved symmetrical 51/51 Gbps speeds over a single fibre strand by using GPON, XGS-PON and NG-PON2 in unison. Deploying this technology in Australia would not require replacing the fibre in the ground, only upgrading the networking equipment on either end.

Long-term technology strategy

While NG-PON2 is still "five to 10 years" away from potential deployment in Australia, it promises to benefit not just broadband users relying on fibre to the premises but all NBN users thanks to the ability to economically upgrade the network's backend fibre links, says NBN chief technology officer Dennis Steiger.

"The option is certainly there for NG-PON2 to be used as a last mile solution, benefiting fibre to the premises, but the technology can also be used to increase the performance of fibre backhaul – perhaps running to a network node, or even a Fixed Wireless base station," Steiger says.

"Because the speeds delivered by NG-PON2 are so high, you'll probably see it first deployed in backhaul areas of the network which require an upgrade, but over time I certainly expect it will be deployed in other areas including all the way out to the end user premises."

NBN has been evaluating NG-PON2 for more than 12 months but has not yet committed to the technology, which Steiger says is yet to be deployed in scale anywhere in the world. The decision is likely to be made "over the next year or two" but, should it get the go ahead, NG-PON2 would be deployed where required rather than in a blanket nationwide rollout.

Along with raw speed, the upgrade would also allow NBN to improve Quality of Service and load balance traffic between wavelengths to reduce network congestion and improve peak hour performance.

Part of the mix

Initially 93 per cent of Australian premises were destined to receive fibre to the premises, but under the new-look Multi-Technology Mix NBN this will drop to around 20 per cent with the rest relying on fibre to the basement, curb, or node, or else utilising the existing HFC cable pay TV network. Either way, 7 per cent of premises – mostly in regional and remote Australia – were always destined to rely on either Fixed Wireless or SkyMuster satellite for NBN access.

NBN's NG-PON2 demonstration comes as the focus on the national network shifts from raw speed to network congestion and sluggish peak performance. In response the Australian Competition and Consumer Commission recently announced plans to monitor real-world download speeds, to identify inadequacies in NBN infrastructure along with areas where with RSPs are not buying enough bandwidth from NBN to satisfy peak demand.

As the nationwide rollout approaches the halfway mark, NBN also recently revealed plans to double Fixed Wireless performance. It demonstrated 100Mbps Fixed Wireless speeds in regional Victoria, with plans to offer this speed tier to RSPs across the country early next year and the potential for further speed boosts down the track. Likewise NBN plans to begin upgrading the HFC cable network this year to support the DOCSIS 3.1 standard, boosting maximum download speeds from 100Mbps to 1Gbps and potentially faster.

Meanwhile new copper-based technologies such as G.fast and XG.FAST have the potential to boost the speeds of fibre to the node, curb and basement connections, which still rely on copper telephone lines to cover the final link to the premises. In 2016 a XG.FAST trial saw NBN achieve speeds of 8Gbps over a 30-metre twisted-pair copper line.

"All the access technologies are evolving very rapidly," Steiger says. "While advances like NG-PON2 aren't on the rollout map at this point, they feature heavily in our technology strategy over the next five to 10 years."