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German incumbent reaches 11 Gbps over 50-metre copper lines albeit under lab conditions.
Deutsche Telekom has become the latest operator to try out XG-Fast as a means of squeezing more capacity out of its copper broadband network.
The test took place under laboratory conditions in late 2015 using equipment developed by Alcatel-Lucent, which has since been taken over by Nokia.
In the test, Deutsche Telekom reached bandwidth speeds of more than 11 Gbps on bonded pairs of Cat 6 cables 50 metres in length. Using standard cables typical of those installed in buildings, the telco achieved a speed of around 8 Gbps over the same distance.
"Working on this demonstration we can see the future possibilities of XG-Fast in maximising existing assets. This will provide another technology option which could enable us to offer high-speed connectivity to our customers quickly and cost-effectively, and at the same time, move our fibre infrastructure closer to our customers," said Deutsche Telekom CTO Bruno Jacobfeuerborn.
"As a global leader in ultra-broadband fixed access we are offering operators a mix of fibre and copper technologies to deploy high-quality services more quickly and cost-effectively," added Federico Guillén, president of fixed networks, Nokia. "The XG-Fast trial with Deutsche Telekom represents an important milestone in our ongoing efforts to extend the potential of copper for delivering ultra-fast speeds."
XG-Fast, first shown off by the Alcatel-Lucent’s Bell Labs division in 2014, works similarly to G.fast by significantly increasing the frequency range used to transmit data over copper. While G.fast uses a frequency range of 106 MHz and reaches speeds of up to 500 Mbps, XG-Fast uses up to 500 MHz and can reach substantially higher speeds.
The trade-off though is that the performance of XG-Fast degrades substantially over distances longer than 100 metres, whereas G.fast can sustain faster speeds over longer lengths of copper.
Other than Deutsche Telekom, U.K. incumbent BT has also tested XG-Fast. Under real-world conditions at its Adastral Park research centre, BT achieved speeds of 5.6 Gbps over 35 metres of cable. However, at more than 100 metres, the speed dropped to 1.8 Gbps.
Critics argue that new copper technologies like G.fast and XG-Fast simply delay the inevitable requirement to upgrade to all-fibre networks, whereas proponents argue that relative to fibre they offer a cheap, quick means of delivering ultrafast broadband.
