Advanced Copper AND Fibre Optics

The National Broadband Network wired format that exists today is comprised of both pure fibre optics and hybrid connections: the latter is a mix of fibre and older copper systems: Mixed Technology NBN. It is also part of its future as far as NBN long term presence in Australia is concerned.

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Originally, the Labor party planned to proliferate pure fibre NBN lines in its early roll out campaign. This plan was marked as excessive in budget and would take much more time, effort, and complexities to carry out.

In order to address concerns possible expensive campaigns that would also break set goal time constraints, the Coalition proposed the use of Mixed Technology NBN. It proved to be more flexible, cheaper, and faster to roll out and install. When the Coalition took over after the elections, this version of the NBN roll out was carried out.

A main concern from its use though, fixated on the speed and performance, particularly the copper elements in place. Copper was originally planned to be phased out and replaced by pure fibre in the roll out. The solution was to focus on optimising the copper elements to eliminate key issues.

Today’s technology for other wired NBN systems still makes use of copper by way of newer optimisation and advanced copper transmission technologies. Elements of VDSL (Very HIGH bit rate Digital Subscriber Line), XG.Fast, and G.Fast are what comprise the next step of Mixed Technology NBN. An addition to the NBN arsenal, it’s also a solution in an effort to match fibre optics while retaining existing copper facilities.

Copper stays in the NBN

As NBN continues with its roll out, the issues presented previously were met with the advancement of hybrid / Mixed technology systems. These connections combine both Fibre and Advanced Copper, while carrying the speed and performance of a pure fibre connection. These advanced copper systems along with the existing ones are being retained as part of the current roll out. It is the logical solution to properly address the demand.

Copper networks exist in significant numbers across Australia. Most of these can be converted into hybrid connections. It will answer some of the growing demand for NBN connections, rather than completely take over and replace them. The copper involvement is up to a certain extent: in the premises area only. All fibre optics equipment and operations will be outside the premises.

How do we optimise the copper elements and make them usable, while keeping up with the properties of fibre optic lines?
The answer can be found by combining the applicable components of VDSL, Vectoring and FTTH or Fibre to the Home NBN. These elements enable advanced copper and fibre components to be bridged together in the premises. The resultant speeds and performance is at least up to par with average NBN access. Following Deutsche Telekom’s successful trials last February 2016, NBN Co. replicated these with equal success.

The main issue of speed and performance is now addressed by partnering with newer technologies as a solution to the copper optimisation. The new advanced copper systems are to improve the hybrid connection and create a streamlined environment of pure fibre and mixed technology NBN.

VDSL was the next evolutionary step of latter day ADSL. But G.Fast and XG.Fast are the next evolutionary step of VDSL. The key is the continuity of NBN standards over the advanced copper components, which resulted in high register speeds of 8GBps in the initial trials. This configuration used 30 metres of twisted copper. A previous lab test trial registered the speed result at 5Gbps with 70 metres of the same twisted copper phone cable.

This amplified version of VDSL uses Vectoring, a method to cancel out interference and improve downstream and upstream data transmissions. It is similar to noise cancellation methods. What it does is to cancel out interference (far end crosstalk) in both download and upload activities from the DSLAM part.

Among the benefits of this configuration was no need to remove existing old copper phone lines, or recabling to a fibre format, within the premises. The overall process is sped up with fewer complications on the part of the subscriber.

One of the minor issues was the short distance cycle of copper lines. The source DSLAM (Digital Subscriber Line Access Multiplexer) has to be brought closer as well, which would mean installing additional units as needed for these distance limitations.

So far this and the format’s physical resilience compared to fibre’s very strong capabilities are the minor issues observed from the initial trials and testing. However, this is still a less costly option compared to a full fibre connection all the way through the premises.