NBN to launch DOCSIS 3.1 in late 2018

NBN will enable gigabit speeds on its extensive HFC network through an upgrade to DOCSIS 3.1 at the end of next year, which will be followed by trials of full-duplex DOCSIS.

The National Broadband Network (NBN) company has announced that it is aiming to launch DOCSIS 3.1 technology across its hybrid fibre-coaxial (HFC) network at the end of 2018 after completing trials scheduled to take place in February.

The HFC network, which will serve around 3 million premises in Australia, is being upgraded by Arris, which originally partnered with NBN back in 2015.

"We're launching our first trials on [DOCSIS] 3.1 next February. We're still working out final details on where those trials will be. We will launch [the trials] from around four HFC nodes," NBN's executive manager of corporate media Tony Brown said.

"And with the trial taking place in February, we are then planning to have a commercial launch at the end of the year."

The news follows NBN CEO Bill Morrow last week telling ZDNet that DOCSIS 3.1 would see a "gradual rollout".

Arris president of Network, Cloud, and Services Dan Whalen said Arris will be trialling full-duplex DOCSIS, which could enable 10Gbps symmetrical speeds, with possible full-scale deployments across the globe in 2019.

"Next generation, maybe end of 2018 or 2019, we'll start introducing devices that reside in those nodes that are capable of supporting full-duplex DOCSIS, and that's where you really get into offering symmetrical gigabit services to the home, and you don't need to go and dig up the cable into the home," Whalen said.

Whalen told ZDNet that Arris is currently in talks with NBN on the full-duplex upgrade during this time frame.

"We're already in discussions with NBN on full-duplex DOCSIS and what the requirements would be and when the timing is," he said.

"I would say if it was available today, NBN would be wanting to deploy it today, or work with us in deploying it in some very targeted environments ... those timelines are about right."

According to Brown, HFC users have exhibited "much stronger demand for higher speeds" than those on NBN's fibre-to-the-node (FttN) and fibre-to-the-premises (FttP) networks.

While NBN does not generally break out the speed tiers chosen by fixed-line users on different networks -- last week reporting that 53 percent of all fixed-line users are on the 25/5Mbps speed tier -- Brown said 10 percent of all HFC users are ordering 50Mbps services.

With DOCSIS 3.1 modems, or network terminating devices (NTDs), already in the homes of those with NBN HFC connections, Brown said all NBN now has to do is update the line cards in the cable modem termination systems (CMTS) and upgrade the software.

"Our NTDs that are in the homes right now are 3.1 capable -- they're currently running 3 but they're 3.1 capable -- so for us to go to 3.1, ultimately, we need to have new upstream line cards in the CMTS and a software upgrade. That's the main things that need to be done," he said.

More changes will be needed during the future upgrade to full-duplex DOCSIS, although the CMTS will remain the same.

"There's a number of architectural changes -- distributed access, where you start taking some of the processing power that exists in the head end today and putting it into a device that resides closer to the homes and subscribers inside of a node ... that has to happen first to enable that transition from analogue optics to digital optics," Whalen explained.

"The new investment will be that remote device that exists inside of the node, and then some of the changes that happen between in the optics."

Whalen said DOCSIS 3.1 upgrades on cable networks are taking place across the world, from Europe to North America and Korea.

"We're involved in trials and deployments in over seven different operators in North America today, some of them with varying amounts of spectrum that they're using," he said.

"DOCSIS 3.1 will enable them to open up more and more spectrum on their HFC plant and enable them to offer higher speeds."

According to Whalen, by 2018 there could be a quadrupling or quintupling in the number of DOCSIS 3.1 devices deployed mass market following the early field trials.

Whalen pointed out that HFC upgrades and expansions are more common than fibre rollouts due to cost constraints, efficiency, and the availability of trained staff.

"We're seeing HFC continue to expand in North America, people deploying HFC in those markets ... operators will do that for a number of reasons. One of them is the operational ease of doing it, so there are field technicians, there are trucks that are filled with HFC products for the field techs to go out to do repairs and upgrades and installs, they are all trained and know how to use these products today," Whalen said.

"It's just more expensive to go out and dig up that last mile and deploy [fibre] into the home."

NBN in June announced attaining download speeds of 1Gbps and upload speeds of 100Mbps during a lab trial of DOCSIS -- Data Over Cable Service Interface Specification -- 3.1.

FttP is currently the only NBN technology able to offer 1Gbps speeds until DOCSIS 3.1 is switched on for HFC customers next year, after being delayed from launching in the second half of 2017.

In comparison to frequency-division duplex (FDD) and time-division duplex (TDD), full-duplex DOCSIS sees both downstream and upstream traffic share the same spectrum. Symmetrical multi-gigabit broadband services are made possible through DOCSIS 3.1 technology when combined with full-duplex DOCSIS.