The History of Fibre Broadband

Fibre broadband has transformed the way people connect to the internet. What was once an experimental communications technology based on sending light through incredibly thin strands of glass has become the backbone of modern telecommunications.

Today, fibre networks carry enormous quantities of internet traffic, telephone calls, television services, cloud computing data, video calls and streaming services. Full-fibre broadband can deliver speeds measured in hundreds of megabits or several gigabits per second, while providing a much more reliable connection than the copper-based broadband networks that preceded it.

But fibre broadband did not appear overnight. Its history stretches back more than half a century and involves scientists, telecommunications companies, governments and engineers around the world.

This is the story of how fibre optics developed from a scientific idea in the 1960s into the full-fibre broadband networks being built today.

What Is Fibre Broadband?

Before looking at its history, it is useful to understand what fibre broadband actually is.

Traditional telephone and broadband networks largely depended on copper cables. Electrical signals travelled through the copper wire, carrying telephone conversations and later internet data.

Fibre-optic cables work differently. Instead of electrical signals travelling through metal, information is converted into pulses of light and transmitted through extremely thin strands of glass or plastic.

A modern optical fibre consists of a central core surrounded by a layer called cladding. The difference between the optical properties of these layers allows light to remain inside the fibre through a process known as total internal reflection.

Because light can carry enormous amounts of information, fibre has vastly greater capacity than traditional copper cables.

It also has other advantages. Fibre signals can travel much longer distances before needing amplification, are resistant to electromagnetic interference and can support extremely high data rates.

These characteristics have made optical fibre the foundation of modern telecommunications.

The Early Idea of Sending Information Using Light

The basic idea of transmitting information using light is much older than the internet.

During the nineteenth century, inventors experimented with optical signalling systems. However, these systems generally relied on visible light travelling through the air rather than through a cable.

The development of modern optical fibre required a way of guiding light through a transparent material.

Researchers eventually discovered that light could be guided through glass, but early fibres were extremely inefficient. Impurities in the glass caused large amounts of the light to disappear over relatively short distances.

This made them unsuitable for long-distance telecommunications.

By the middle of the twentieth century, researchers were becoming increasingly interested in the possibility of using light to carry information.

The invention and development of lasers during the late 1950s and early 1960s was particularly important because lasers could provide a concentrated and controllable source of light.

The problem was finding a practical way to send that light over long distances.

Charles Kao and the Fibre-Optic Revolution

One of the most important figures in the history of fibre communications was Charles Kuen Kao.

Kao was working at Standard Telecommunication Laboratories (STL) in Harlow, Essex, in the United Kingdom. In the 1960s, he and colleague George Hockham investigated the possibility of using glass fibres to transmit communications.

At the time, optical fibres suffered from enormous signal losses. It was widely believed that the losses might be an unavoidable consequence of using glass.

Kao reached a different conclusion.

In a landmark paper published in 1966, Kao and Hockham argued that the problem was largely caused by impurities in the glass. If extremely pure glass could be produced, they believed that optical fibre could become a practical communications medium.

Their research suggested that fibre could potentially carry huge quantities of information over long distances.

Kao’s work effectively provided the scientific roadmap for the development of modern fibre-optic communications. His contribution was eventually recognised with the 2009 Nobel Prize in Physics.

The 1970 Breakthrough

The next challenge was turning the theory into reality.

Researchers needed to manufacture glass pure enough to transmit light over useful distances.

A major breakthrough came in 1970 when scientists at Corning Glass Works in the United States developed a low-loss optical fibre.

Robert Maurer, Donald Keck and Peter Schultz worked on the problem of producing extremely pure glass.

Their breakthrough fibre had an attenuation of roughly 16–17 dB per kilometre, beating the 20 dB/km target proposed by Kao.

This was a crucial moment in telecommunications history.

The technology had moved from an interesting scientific concept to something that could potentially be manufactured and used commercially.

Corning subsequently continued improving the technology. By 1972, fibre losses had been reduced to around 4 dB/km, while further improvements during the 1970s eventually produced dramatically lower losses.

The First Practical Fibre Networks

During the 1970s, telecommunications companies began experimenting with optical fibre in real-world networks.

One early application was telephone communications.

In 1975, the US government used fibre to connect computers at the North American Aerospace Defense Command facility at Cheyenne Mountain.

In 1977, AT&T installed an optical telephone system beneath Chicago. Each fibre could carry the equivalent of hundreds of telephone channels.

The technology was also being developed in Britain.

The UK’s telecommunications research organisations played an important role in the development of optical communications. Early commercial fibre transmission systems were demonstrated in Britain during the 1970s, helping establish the country as one of the pioneers of optical telecommunications.

At this stage, however, fibre was primarily being used by telecommunications operators for high-capacity links rather than being connected directly to ordinary homes.

Fibre Replaces Copper in the Telephone Network

During the late 1970s and 1980s, fibre began to move into the core of national and international telephone networks.

This was an important distinction.

Fibre broadband as we know it today did not initially involve a fibre cable running directly into someone’s house. Instead, fibre was first used for the high-capacity parts of telecommunications networks.

Copper telephone cables remained responsible for the connection between local exchanges and homes.

Fibre was ideal for the long-distance sections because it could carry enormous quantities of telephone traffic.

As the technology improved, telecommunications companies increasingly replaced traditional copper trunk networks with fibre.

This created the foundation for the global communications network that would eventually carry internet traffic.

Undersea Fibre-Optic Cables

One of the most important developments was the use of fibre-optic cables under the world’s oceans.

International communications had traditionally relied heavily on submarine copper cables and, later, satellite communications.

Fibre provided a huge increase in capacity.

During the 1980s and 1990s, submarine fibre-optic cables began connecting continents.

These cables became an essential part of the emerging global telecommunications infrastructure.

The result was a dramatic increase in the amount of information that could travel between countries.

Telephone calls, fax transmissions and eventually internet traffic could cross oceans using optical fibre.

The falling cost and increasing capacity of international communications helped create the environment in which the global internet could expand.

The Rise of the Internet

The arrival of the World Wide Web in the early 1990s changed the purpose of telecommunications networks.

Previously, much of the long-distance capacity was being used for telephone calls.

Now there was a rapidly increasing demand for data.

Email, websites, online services and eventually video created enormous demand for additional bandwidth.

Fibre was perfectly suited to this new environment.

The internet also accelerated the development of large-scale fibre networks connecting cities, countries and continents.

During the 1990s, telecommunications companies invested heavily in fibre-optic infrastructure.

The dot-com boom produced another surge in demand.

Although some of the companies and networks created during the dot-com era ultimately failed commercially, the fibre infrastructure built during this period became an important foundation for the future internet.

Fibre Comes Closer to the Home

By the late 1990s and early 2000s, telecommunications companies began looking more seriously at bringing fibre closer to residential customers.

There were several possible approaches.

Fibre to the Cabinet

Fibre to the Cabinet, usually abbreviated to FTTC, involves running fibre from the telephone exchange to a street cabinet.

The final connection from the cabinet to the customer’s home continues to use copper telephone cable.

This was considerably cheaper and quicker to deploy than running new fibre cables all the way to every home.

FTTC therefore became an important transitional technology.

Fibre to the Premises

Fibre to the Premises, or FTTP, takes fibre all the way to the customer’s property.

It is sometimes called Fibre to the Home (FTTH) when the connection is specifically residential.

This eliminates the copper section of the access network.

As a result, FTTP can offer much higher speeds and greater capacity than FTTC.

This distinction would become increasingly important as internet usage grew.

The Early Days of Broadband in Britain

The UK initially relied heavily on copper-based broadband technologies.

Dial-up internet was gradually replaced by broadband during the late 1990s and early 2000s.

ADSL became particularly important.

Using existing copper telephone lines, ADSL allowed people to remain connected to the internet without tying up the telephone line.

Early ADSL connections were dramatically faster than dial-up, but speeds were still measured in megabits rather than the hundreds of megabits and gigabits available from modern fibre connections.

As internet services became more demanding, the limitations of copper became increasingly obvious.

Streaming video, online gaming, cloud services and large downloads all required more bandwidth.

Openreach and the UK Fibre Rollout

A major development in Britain’s broadband history came in 2006 with the creation of Openreach.

Openreach was established following Ofcom’s strategic review of the telecommunications market, with the aim of providing communications providers with fair access to the underlying network.

This became particularly important as the UK began upgrading its broadband infrastructure.

In 2008, Openreach announced a major investment programme and introduced FTTP to a new development in Kent.

The connection offered speeds of up to 100 Mbps, which was exceptionally fast for a residential broadband service at the time.

In 2009, Openreach began FTTC trials in Muswell Hill in North London and Whitchurch in South Wales.

The initial FTTC technology offered download speeds of up to 40 Mbps.

This represented a major step forward from traditional ADSL.

FTTC Becomes Mainstream

During the early 2010s, FTTC became one of the main methods of delivering faster broadband in Britain.

Instead of replacing every copper cable between the exchange and each home, operators could install fibre between the exchange and a street cabinet.

The existing copper network then handled the final connection.

This approach allowed broadband companies to upgrade large parts of the network relatively quickly.

Speeds increased as the technology developed.

Openreach reports that FTTC download speeds were increased to up to 76 Mbps in 2012.

By 2013, approximately 15 million UK homes and businesses could order fibre broadband through the Openreach network, with more than 1.5 million already connected.

By 2016, fibre broadband was available to around 25 million homes and businesses, with approximately 5.9 million connected.

The Problem With FTTC

Although FTTC was a major improvement over ADSL, it still depended on copper.

The speed available to an individual customer could therefore depend on the length and quality of the copper cable between the cabinet and the property.

Generally, the shorter the copper connection, the better the potential performance.

This created an important limitation.

As internet usage continued to grow, simply making the copper connection faster became increasingly difficult.

The industry therefore began moving towards a different goal: full fibre.

The Growth of FTTP

FTTP removes the copper connection entirely.

Instead, fibre runs from the network directly to the premises.

This allows much greater bandwidth and removes many of the limitations associated with copper telephone cables.

The technology also provides a network capable of supporting future speed increases without necessarily replacing the physical fibre cable.

This concept of a future-proof network became one of the main arguments for full-fibre investment.

During the late 2010s and early 2020s, the UK saw a dramatic increase in FTTP deployment.

Openreach was joined by a growing number of alternative network operators, often known as “altnets”.

Companies began building their own fibre networks, increasing competition in the broadband market.

Gigabit Broadband

Another major change was the arrival of gigabit broadband.

A gigabit connection can theoretically provide around 1,000 Mbps, or 1 Gbps.

That is considerably faster than the typical broadband services of the early 2000s.

Gigabit fibre made it possible for households to download very large files quickly, stream high-resolution video, run multiple simultaneous connections and use cloud-based services without placing the same strain on the connection.

For businesses, fibre also enabled faster access to cloud computing, remote desktops, hosted applications, online backup and other services.

The importance of upload speeds also became increasingly apparent.

Traditional broadband services often offered much slower upload speeds than download speeds.

Full fibre can provide much higher upload capacity, and some modern services offer symmetrical connections with similar upload and download speeds.

Fibre During the COVID-19 Pandemic

The COVID-19 pandemic highlighted the importance of broadband infrastructure.

During periods of lockdown, millions of people depended on their internet connections for work, education, communication and entertainment.

Video conferencing became part of everyday life.

Businesses moved many operations online, while schools and universities relied heavily on digital services.

The increased demand reinforced the argument for investing in high-capacity broadband infrastructure.

A connection that might previously have been considered extremely fast could suddenly be shared by several people working, studying, streaming and gaming from the same home.

Full fibre became increasingly attractive because of its capacity and reliability.

The UK Moves Towards Full Fibre

During the 2020s, the UK broadband market entered a period of rapid fibre expansion.

Openreach dramatically increased the pace of its FTTP construction programme, while other network operators built competing full-fibre networks.

Government policy also increasingly focused on gigabit-capable and full-fibre infrastructure.

The scale of the change has been substantial.

In March 2026, Ofcom reported that full-fibre broadband was available to 78% of UK homes, compared with less than a quarter five years earlier.

Openreach says it is continuing to expand its network, with an ambition to reach 25 million premises by the end of 2026 and 30 million by 2030, subject to regulatory conditions.

This represents a remarkable transformation from the copper-based network that dominated British telecommunications for much of the twentieth century.

The Difference Between Fibre Broadband and Full Fibre

The term “fibre broadband” can sometimes be confusing.

A service advertised as fibre does not necessarily mean that the connection is fibre all the way to the home.

There are several technologies.

ADSL:
Uses copper telephone lines from the exchange to the property.

FTTC:
Uses fibre to a street cabinet, followed by copper to the property.

FTTP/FTTH:
Uses fibre all the way to the premises.

Full Fibre:
Generally refers to an access connection where fibre runs all the way to the customer’s premises.

This distinction explains why two broadband packages both described as “fibre” can offer very different performance.

Why Fibre Is So Much Faster

The enormous capacity of fibre comes from the way information is transmitted.

Copper uses electrical signals.

Fibre uses light.

Light can be switched on and off extremely rapidly, allowing information to be encoded into pulses and transmitted through the glass.

Modern optical communications systems can also use different wavelengths of light simultaneously.

This means that a single fibre can carry multiple streams of information at the same time.

Researchers and network operators have continued to increase capacity through improvements in lasers, modulation, signal processing, wavelength division multiplexing and other technologies.

As a result, the capacity of fibre networks has increased enormously since the first experimental systems.

Fibre and the Modern Internet

Today, fibre is much more than a broadband technology.

It is the foundation of the internet itself.

Fibre connects:

• Homes and businesses
• Telephone exchanges
• Mobile phone networks
• Internet service providers
• Data centres
• Cloud computing platforms
• Content delivery networks
• Universities
• Government networks
• International telecommunications systems
• Submarine communications cables

Even when a smartphone connects wirelessly to a mobile network, much of the traffic will eventually travel through fibre.

The same is true for Wi-Fi.

A device may communicate with a wireless router using radio waves, but the router can be connected to the internet through a fibre-optic broadband connection.

Fibre therefore forms the hidden infrastructure behind much of modern digital life.

Fibre and 5G

The growth of 5G has also increased the importance of fibre.

Although 5G provides wireless connectivity, mobile networks require high-capacity connections between mobile sites and the wider internet.

These connections are increasingly provided by fibre.

This is sometimes called mobile backhaul or transport.

As mobile networks become faster and more data-intensive, fibre becomes even more important.

The same principle will apply to future generations of mobile technology.

Fibre and Data Centres

The growth of cloud computing has created another enormous demand for fibre.

Services such as online storage, streaming platforms, web applications and artificial intelligence rely on huge data centres.

These facilities need extremely high-capacity connections to communicate with other data centres, internet exchanges, businesses and consumers.

Modern data centres can contain enormous quantities of optical networking equipment.

Fibre therefore connects not only people’s homes but also the machines that provide many of the services people use every day.

The Retirement of the Copper Network

As full fibre becomes more widely available, telecommunications operators are beginning to retire older copper infrastructure.

In Britain, the traditional telephone network is being replaced by digital communications technologies.

Openreach has described the transition as part of a move away from the old copper-based network.

This is a major technological change.

For generations, the copper telephone network was one of the most important pieces of infrastructure in Britain.

It carried analogue telephone calls, fax traffic and eventually broadband internet.

The transition to fibre represents the end of an era.

The Future of Fibre Broadband

Although modern fibre broadband is already extremely fast, the technology is nowhere near its final limits.

The physical fibre cable installed today can potentially support much higher speeds in the future through improvements in optical equipment.

This is one of the reasons fibre is considered a long-term infrastructure investment.

A network capable of hundreds of megabits per second today can potentially be upgraded to gigabit, multi-gigabit or even much higher speeds by replacing equipment at either end rather than replacing the fibre itself.

Future developments are likely to include:

• Faster multi-gigabit residential connections
• Higher upload speeds
• Greater use of symmetrical broadband
• More advanced optical networking
• Higher-capacity submarine cables
• Faster data-centre connections
• Improved fibre sharing technologies
• Greater integration between fibre and 5G/6G networks
• More fibre deployment to rural areas

The continuing growth of cloud computing, artificial intelligence, streaming, gaming and connected devices will keep increasing demand for bandwidth.

From an Experiment in Glass to the Global Internet

The history of fibre broadband is ultimately a story about solving a deceptively difficult problem: how to send enormous quantities of information over long distances.

In the 1960s, scientists such as Charles Kao recognised that glass could potentially become a communications medium if its impurities could be controlled.

The breakthrough by Corning researchers in 1970 demonstrated that low-loss fibre could actually be manufactured.

During the following decades, fibre moved into telephone networks, submarine cables, internet backbones, data centres and eventually residential broadband.

The UK played an important role in this story, particularly through the work of Charles Kao and researchers at Standard Telecommunication Laboratories in Harlow.

What began as a research project involving tiny strands of glass eventually became the foundation of the global digital communications network.

Today, when someone connects a computer to a full-fibre broadband service, they are benefiting from more than half a century of research and engineering.

The fibre cable running into a modern home may look simple, but behind it lies one of the most important technological developments in the history of telecommunications.

From the first experiments with light in glass to today’s gigabit broadband services, fibre has fundamentally changed how the world communicates.

And as demand for data continues to grow, the humble strand of glass is likely to remain at the heart of the internet for decades to come.

Fibre Broadband Timeline

1966 – Charles Kao and George Hockham publish their influential research showing that sufficiently pure glass could potentially be used for long-distance optical communications.

1970 – Corning develops a practical low-loss optical fibre, achieving attenuation below Kao’s target.

1975 – Fibre is used for early high-capacity communications applications, including a US government network.

1977 – AT&T installs an optical telephone system in Chicago.

1980s – Fibre becomes increasingly important in national and international telephone networks.

1990s – The rapid growth of the internet drives huge demand for fibre capacity.

2000 – Broadband begins replacing dial-up as the UK’s mainstream consumer internet technology.

2006 – Openreach is created in the UK.

2008 – Openreach introduces FTTP to a new development in Kent, while the UK’s first residential full-fibre connection is recorded at Ebbsfleet.

2009 – Openreach begins FTTC trials.

2012 – FTTC speeds increase to up to 76 Mbps and FTTP services expand.

2013 – Fibre broadband becomes available to around 15 million UK homes and businesses through the Openreach network.

2016 – Fibre is available to around 25 million UK homes and businesses through Openreach.

2020s – Full-fibre and gigabit broadband deployments accelerate across Britain.

2026 – Ofcom reports that full fibre is available to 78% of UK homes, while the UK’s major fibre networks continue expanding.

Conclusion

Fibre broadband is the result of decades of innovation rather than a single invention.

Charles Kao’s research provided the vision. The development of low-loss glass made that vision practical. Telecommunications companies then transformed the technology into national and international networks.

Eventually, fibre moved from the core of the telephone system towards individual homes and businesses.

The transition from copper to fibre is now one of the biggest infrastructure changes in the history of telecommunications.

The internet that people use every day — from streaming and social media to cloud computing, online gaming and artificial intelligence — depends on an enormous global network of optical fibre.

What started as an experiment involving light travelling through a tiny strand of glass has become the foundation of the connected world.