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The challenge of replacing the UK copper network with fibre

Thu 1 Jul 2021

Copper wires have provided the UK with communications and broadband services to the country for over 100 years, so why do we need to change to fibre?

UK communications regulator Ofcom is aiming to complete a copper-to-fibre communications network no later than 2025. While four years seems like a lengthy timeline, in truth, completing a project on this scale is an extremely ambitious goal.

Copper wires have formed the backbone of the communications network since 1911, and are currently used to deliver broadband services across much of the country, to individuals, organizations, and businesses. However, this infrastructure is ageing, badly – and to support ‘gigabit-capable connectivity’ these copper wires must be replaced by fibre.

Why replace copper?

While copper wires have been upgraded and improved to meet some of the needs of modern telecommunications, there are still a number of reasons that a copper-to-fibre switchover makes sense.


Customer expectations for increased bandwidth – faster internet connections, data transfer, downloads, streaming services – keep rising. Copper transmissions often max out at around 40 Gbps, while fibre optic cables can move data at the rate of hundreds of Tbps. This is a major factor in the appeal of ‘gigabit-capable connectivity’ – being able to satisfy the data speed requirements of individuals and enterprises both now and in the future.


Fibre optic cables are much smaller than copper wires – approximately ¼ the size of a category 6 standard copper wire. Not only does a fibre cable move data faster, but more cables can be packed into a single conduit, increasing the total communications capacity per conduit.

Additionally, the smaller profile of fibre cables improves air circulation, which may help significantly with data centre cooling.

Durability and Reliability

While copper wire is larger than fibre optics (and not made of glass), it still has a lower tolerance for tension, making it more fragile and prone to require maintenance.  Fibre is also lighter and more durable than copper so that it needs less maintenance and repair.

Fibre is more reliable than copper, as well. Countries like Estonia and Sweden, which have already completed a switchover from copper to fibre, report 70% fewer cable faults.


Communications degrade in quality over distance, regardless of whether they are sent over copper or fibre. However, fibre optic cables carry communications much farther. Copper cables are limited to around 100m of transmission distances, whereas fibre cables can transmit for distances of around 38 km.

While these benefits are straightforward, delivering 100% fibre connectivity for the entire UK is not. There are many serious challenges to achieving this by 2025, including:


Ideally, copper wires should not be retired until the fibre network is complete – ensuring that the switchover causes minimal service interruptions to public entities, private businesses, and individual activities.

Disruptions will likely be impossible to avoid, however. First, copper wires require an enormous amount of maintenance to keep them in good working order. While Ofcom and telecommunications providers like BT are committing resources to replace copper with fibre, it is likely that some of those resources will be moved away from maintaining copper networks. This means that copper services will degrade more quickly before fibre services are available.

There are other disruptions associated with the transition as well. It is likely that the switchover will require construction projects, road work, and other physical infrastructure adaptations. It will also create significant administrative work: changes must be communicated effectively, customer agreements must be updated and recorded, and new services deployed.

Rural Areas

Making changes in urban areas is likely to be quite disruptive. But extending fibre services to rural areas presents another set of challenges. There is a greater distance between network connections, making it more difficult to exchange copper for fibre. Fewer crews are available in rural areas than in cities, posing project management and organizational challenge for telecom providers. To help with this, the UK government has allocated £5bn of public funding to support infrastructure rollout in the most challenging 20% of the UK.


Because the switchover will take enormous resources to complete, there has been concern that the largest telecom providers will have an unfair advantage over smaller companies, eroding competition and fair pricing. This worry was made worse when Ofcom announced that once Openreach (a BT company managing most of the UK’s copper network) reaches a certain percentage of full-fibre coverage in an area, regulations related to copper-based communications will be lifted. The stated reason for this was that Openreach should not be required to bear the cost of running two separate networks in parallel. However, consumers may interpret this as a way of limiting their choice.

So how did the UK decide that the benefits outweighed the challenges in supporting and promoting a switchover from copper to fibre?

Ofcom Chief Executive Melanie Dawes said, “Over the past year, being connected has never mattered more. But millions of homes are still using the copper lines that were first laid over 100 years ago. Now it’s time to ramp up the roll-out of better broadband across the UK.”

“We are playing our part, setting the right conditions for companies to step up and invest in the country’s full-fibre future. This is a once-in-a-century chance to help make the UK a world-leading digital economy.”


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