Alcatel-Lucent has announced that it has transmitted 10 GBS over copper wires.
Here's an excerpt from the announcement:
Bell Labs, the research arm of Alcatel-Lucent (Euronext Paris and NYSE: ALU), has set a new broadband speed record of 10 gigabits-per-second (Gbps) using traditional copper telephone lines and a prototype technology that demonstrates how existing copper access networks can be used to deliver 1Gbps symmetrical ultra-broadband access services. . . .
The Bell Labs tests used a prototype technology called XG-FAST. This is an extension of G.fast technology, a new broadband standard currently being finalized by the ITU. When it becomes commercially available in 2015, G.fast will use a frequency range for data transmission of 106 MHz, giving broadband speeds up to 500 Mbps over a distance of 100 meters. In contrast, XG-FAST uses an increased frequency range up to 500 MHz to achieve higher speeds but over shorter distances. Bell Labs achieved 1 Gbps symmetrical over 70 meters on a single copper pair. 10 Gbps was achieved over a distance of 30 meters by using two pairs of lines (a technique known as "bonding"). Both tests used standard copper cable provided by a European operator.