UK requires internet infrastructure overhaul to meet future needs, report finds
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The UK’s existing copper network cables are running out of capacity to support faster internet speeds and the government needs to urgently provide additional investment to meet its commitment to making high-speed internet available to all, a report has found.
Researchers from the University of Cambridge and BT have established the maximum speed at which data can be transmitted through existing copper cables. This limit would allow for faster internet compared to the speeds currently achievable using standard infrastructure but will not be able to support high-speed internet in the longer term.
The team found that the ‘twisted pair’ copper cables that reach every house and business in the UK are physically limited in their ability to support higher frequencies, which in turn support higher data rates.
While full-fibre internet is currently available to around one in four households, it is expected to take at least two decades before it reaches every home in the UK. In the meantime, however, existing infrastructure can be improved to temporarily support high-speed internet.
The results establish a physical limit on the UK’s ubiquitous copper cables, and emphasise the importance of immediate investment in future technologies.
The Cambridge-led team used a combination of computer modelling and experiments to determine whether it was possible to get higher speeds out of existing copper infrastructure and found that it can carry a maximum frequency of about 5GHz, above the currently used spectrum, which is lower than 1GHz. Above 5GHz however, the copper cables start to behave like antennas.
Using this extra bandwidth can push data rates on the copper cables above several gigabits per second on short ranges, while fibre cables can carry hundreds of terabits per second or more.
“Any investment in existing copper infrastructure would only be an interim solution,” said co-author Dr Anas Al Rawi from Cambridge’s Cavendish Laboratory. “Our findings show that eventual migration to optical fibre is inevitable.”
Twisted pair cables replaced earthed lines by the end of the 19th century and have been highly reliable ever since. Today, they are standardised to carry 424MHz bandwidth over shorter cable lengths owing to deeper fibre penetration and advances in digital signal processing.
These cables are now reaching the end of their life as they cannot compete with the speed of fibre-optic cables, but it’s not possible to get rid of all the copper cables due to fibre’s high cost.
While the fibre network is getting closer to residential areas, the connection between the fibre network and houses will continue to rely on the existing copper infrastructure.
The report recommends greater investment in technologies that can support the fibre networks on the last mile to make the best use of them.
“High-speed internet is a necessity of 21st-century life,” said first author Dr Ergin Dinc. “Internet service providers have been switching existing copper wires to high-speed fibre-optic cables, but it will take between 15 and 20 years for these to reach every house in the UK and will cost billions of pounds. While this change is happening, we’ve shown that existing copper infrastructure can support higher speeds as an intermediate solution.”
Based on their results, the researchers have called for the government and industry to work together to invest more heavily in the UK’s future digital infrastructure.
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