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Source: The Conversation (Au and NZ) – By Thas Ampalavanapillai Nirmalathas, Group Head – Electronic and Photonic Systems Group and Professor of Electrical and Electronic Engineering, University of Melbourne

The federal government has announced a A$3.5 billion upgrade to the National Broadband Network (NBN) that will grant two million households on-demand access to faster fibre-to-the-node (FTTN) internet by 2023.

The plan may go as far as to upgrade the FTTN services to fibre-to-the-premises (FTTP), but this wasn’t made entirely clear in communications minister Paul Fletcher’s announcement.

He said the upgrade would involve expanding current FTTN connections to run along more streets across the country, giving more people the option to connect to broadband speeds of up to one gigabit per second. Improvements have also been promised for the hybrid fibre coaxial (HFC) and fibre-to-the-curb (FTTC) systems.

Altogether the upgrades are expected to give about six million households the higher broadband speeds. But how will the existing infrastructure be boosted? And who will miss out?

Getting ahead of the terminology

Let’s first understand the various terms used to describe aspects of the NBN network.

Fibre to the Premises (FTTP)

FTTP refers to households with an optical fibre connection running from a device on a wall of a house directly to the network. This provides reliable high-speed internet.

The “network” simply refers to the exchange point from which households’ broadband connections are passed to service providers, such as Telstra, who then help them get connected.

In a FTTP network, fibre optic connectors in the back of distribution hub panels connect homes to broadband services. Shutterstock

Fibre to the Node (FTTN)

The FTTN system serves about 4.7 million premises in Australia, out of a total 11.5 million covered under the NBN.

With FTTN, households are connected via a copper line to a “node” in their neighbourhood. This node is connected to the network with fibre optic cables that transfer data much faster than copper cables.

With FTTN systems, the quality of the broadband service depends on the length of the copper cabling and the choice of technology used to support data transmission via this cable.

It’s technically possible to offer high internet speeds when copper cables are very short and the latest data transmission technologies are being used.

In reality, however, Australia’s FTTN speeds using a fibre/copper mix have been slow. A FTTN connection’s reliability also depends on network conditions, such as the age of the copper cabling and whether any of the signal is leaking due to degradation.

Illustration of fibre optic cables.
Fibre optic cables can use pulses of light for high-speed data transmission across long distances. Shutterstock

Fibre to the Curb (FTTC)

The limitations of FTTN can be sidestepped by extending fibre cables from the network right up to a curbside “distribution point unit” nearer to households. This unit becomes the “node” of the network.

FTTC significantly improves data transmission speeds. This is because it services relatively fewer households (allowing better signal transmission to each one) and reduces the length of copper cable required.

Hybrid Fibre Coaxial (HFC)

The NBN also uses coaxial cables instead of copper cables in many areas. These were first installed by Optus and Telstra in the 1990s to deliver cable broadband and television. They have since been modernised for use in the NBN’s fibre network.

In theory, HFC systems should be able to offer internet speeds of more than 100 megabits per second. But many households have been unable to achieve this due to the poor condition of cabling infrastructure in some parts, as well as large numbers of households sharing a single coaxial cable.

Coaxial cables are the most limiting part of the HFC system. Expanding the length of fibre cabling (and shortening the coaxial cables being used) would allow much faster internet speeds. The NBN’s 2020 corporate plan identifies this as a priority.

The minister today said the planned upgrades would ensure all customers serviced by HFC would have access to speeds of “up to” one gigabit per second. Currently, only 7% of HFC customers do.

Mixing things up isn’t always a good idea

Under the original NBN plan, the Labor government in 2009 promised optical fibre connections for 93% of all Australian households.

Successive reviews led to the use of multiple technologies in the network, rather than the full-fibre network Labor envisioned. As a result, many households have not been able to upgrade their connection because of limitations to the technology available in their neighbourhood.

Read more: The NBN: how a national infrastructure dream fell short

Also, many businesses currently served by FTTN can’t access speeds that meet their needs. To avoid internet speed hindering their work, most businesses need a minimum speed between 100 megabits and 1 gigabit per second, depending on their scale.

Currently, no FTTN services and few HFC services can support such speeds.

Moreover, the Australian Competition and Consumer Commission’s NBN monitoring report published in May (during the pandemic) found in about 95% of cases, NBN plans only delivered 83-91% of the maximum advertised speed.

The report also showed 10% of the monitored services were underperforming and 95% of these were FTTN services. This makes a clear case for the need to upgrade FTTN.

Who will benefit?

While the NBN’s most recent corporate plan identifies work to be done across its various offerings (FTTN, FTTC, HFC, fixed wireless), it’s unclear exactly what each system stands to gain from today’s announcements.

Ideally, urban and regional households that can’t currently access 100 megabits per second speeds would be prioritised for fibre deployment. The expanded FTTN network should also cover people who are struggling to access reliable broadband across regional Australia.

Bringing fibre cabling to households in remote areas would be difficult. One option, however, would be to extend fibre connections to an expanded network of base stations in regional Australia, to improve the NBN’s capacity for fixed wireless connectivity.

These base stations can “beam” signals to nearby premises. Installing more stations would mean fewer premises covered by each (and therefore better connectivity).

Regardless, it’s important the expansion happens quickly. Many NBN customers now working and studying from home will be waiting for a much-needed boost to their internet speed.

Read more: How to boost your internet speed when everyone is working from home

ref. NBN upgrades explained: how will they make internet speeds faster? And will the regions miss out? –