Fibre to the curb: How NBN is delivering its new network

Australia's National Broadband Network (NBN) company has begun deploying its fibre-to-the-curb (FttC) network across Sydney and Melbourne, with the service bringing fibre closer to the home for 1.5 million premises by installing it in pits at the end of customers' driveways.

While the network technology will provide faster speeds for end users than its fibre-to-the-node (FttN) network, NBN has emphasised the added complexity and time in rolling out the network by showcasing the process involved in Sydney on Tuesday.

NBN chief engineering officer Peter Ryan told ZDNet that it takes around five months from start to finish to connect an FttC area serving around 2,500 premises -- although variability is quite high due to the need to bore along footpaths.

Prior to the boring process, however, workers have to first locate any existing cabling in the ground, such as other telco services, water, power, and gas, which could take between one and three days to locate. According to contractors working on an FttC boring site in Burwood, Sydney, the existing registers of underground cabling are unreliable, and often do not have lines listed.

Once the boring does begin, contractors are able to complete between 50 and 70 metres per day, equating to approximately five houses. On completion of this process, NBN is then required to re-concrete or re-seed any ground that has been disturbed within 10 days.

Ducting is then installed with fibre following the boring, with an FttC distribution point unit (DPU) placed into an existing pit located within a 150-metre copper length of each premises to be serviced. According to Ryan, most pits also have to be expanded to fit the DPUs in, however.

"We've got to upgrade a lot of pits with FttC compared to [Ftt]N; also, the pits we're typically upgrading are often asbestos, so the effort to upgrade it is substantial," he said.

Once the DPU has been dropped into the pit, NBN then pre-tests the network "extensively", Ryan said.

"So when we drop that DPU in, and the construction guys integrate that piece of equipment, which is an active piece of equipment, they first test it from here back up the fibre back up to the exchange, and the exchange and the network registers that DPU to that location, it integrates it into the network once it's recognised," he explained.

"Secondly, we then have to identify exactly which piece of copper is running from with this house into that house, and you can see when you look into these pits, there's a fair bit of cable going everywhere, but we have to know exactly which one goes to that house versus that house versus that house."

Once NBN has identified which cabling goes with which premises and integrated the DPU into the network, the workers "literally cut our DPU into the piece of copper" that forms the lead-in for each premises.

"Before we do that, just to add to the complexities, we've got to make sure that inside that house, we don't have a medical alarm or any special services hanging off that, otherwise that kicks it into a different process, because you can imagine that as soon as we cut it in, there's a small outage," he added.

"We have to manage that outage and the risk hanging off it."

According to Ryan, all of this additional pre-testing and construction work is to ensure that consumers can then painlessly self-install their connections, with this process also removing the necessity to wait for an installer to arrive -- with missed installation appointments one of the biggest causes for consumer complaints about NBN.

"One of the things we're doing, we're working extremely hard on and we're very focused on, is making sure that the customer experience at the point of activation for FttC customers is fantastic, and one of the differences with FttC is we're doing self-installs for customers," Ryan said.

"So far, we're seeing really high success rates when we do that, and we've done that two ways: One, we get the construction right; two, with the RSPs, we've worked really hard."

Ryan lauded Telstra's work on this process, saying the incumbent telco repackages NBN's self-installation box into a single integrated box with Telstra's own home modem equipment and an instruction manual for a customer.

He said NBN has built a system to detect as soon as a customer plugs in their modem, which then flips a switch to direct the traffic off the Telstra copper and onto the NBN fibre network.

"The moment we detect data on that line, we complete the activation and close the order," he said.

"So far, we're seeing a success rate of over 80 percent of that happening, which actually for an early stage technology is phenomenal."

In current tests of attainable line speeds on FttC all the way into houses, NBN is seeing more than 90Mbps download.

NBN is now beginning to use Nokia's new DPUs across its FttC network, which contain dual-mode functionality for the current VDSL technology being used, as well as for the G.fast upgrade that will be rolled out in the second half of this year to enable gigabit speeds.

Once the G.fast upgrade is available, NBN will be able to flick the DPUs remotely to the mode, while customers will be sent new modems to plug in.

"This [DPU] was designed with NBN in mind -- for size, robustness of those pits, ease of activation, ease of operation, which is key to the customer experience at the end of the day, and then for a quick upgrade to G.fast as and when NBN decides to launch that as a product, or as there is demand in the market," head of Marketing and Corporate Affairs for Nokia Oceania Tim Marshall said.

"These are starting to go into pits now in Sydney and Melbourne, I think they're in a live trial situation right now.

"We did some lab trials or lab demos last week on this exact piece of equipment over a 70-metre line of cable and achieved 1.1Gbps down and 400Mbps up on this device running in G.fast mode."

According to Marshall, the DPU compresses the FttN line card technology into a smaller DPU to fit the FttC model. Each DPU serves four premises; by comparison, an FttN node switch-on instantly connects almost 400 premises.

So while the FttC network is "more future-proof", there is a lot more work to get there, Ryan concluded.

NBN activated more than 600 premises last week, he said, with around 2,000 now live on the FttC network and 18,500 ready for service as of May.

"In the early deployments of our technologies typically, historically, what we see is a drop in satisfaction as we get through teething problems and we bring that back. In FttC, because of all the work we're doing in the field, both aligning the data, getting the logical and the physical right, we're not seeing that early teething happening," Ryan said.

"We've challenged ourselves to deliver a great customer experience from the get-go, and thankfully we are starting to see that."

Recent NBN Coverage

• Labor to provide 'NBN service guarantee' if elected
• From 358 Area Switch applications, NBN has upgraded two MDUs so far
• Almost half of all NBN users now on 50Mbps or faster
• Superloop coughs up AU$1.5m for SkyMesh fixed line NBN customers
• Western Australia wants 100Mbps minimum NBN speeds and CVC canned
• ACCC needs AU$6m more to monitor NBN fixed-wireless speeds
• Software automation policy guidelines (Tech Pro Research)
• NBN considers throttling 'extreme' fixed-wireless users
• NBN remediating 3Mbps fixed-wireless cells
• NBN to overhaul fixed-wireless pricing
• Optus fined AU$1.5m for misleading NBN customers
• NBN announces business satellite service for 2019
• NBN: More to be done on HFC remediation
• NBN looks to 'proactive' network health with machine learning