A new standard for DSL, G.fast, can reach speeds of up to a gigabit of data per second, though its performance drops rapidly once the copper wires extend for more than 100 meters. That's enough to get service from a very nearby service closet but not much beyond that. Are we at the end of the line for the technology?

Maybe not. The engineers at Bell Labs, however, said that its customers—ISPs in this case—have other ideas. It's not easy to run fiber through every town or into every building, and ISPs see opportunities for higher-tier services over copper wires. So Bell Labs has joined a number of companies in working on a technology that can reach 10Gbps over copper wiring, and Ars got a chance to look at some of the preliminary hardware.

The new tech is limited to a distance of only about 50 m before the dropoffs become substantial, but that's enough to handle services like fiber to the driveway or fiber to the floor of a multifamily dwelling.

Further Reading Bell Labs pushes 10Gbps over copper telephone lines

Bell Labs' technology is based on G.fast, which relies on two pairs of twisted copper wires. This system is found in any home that once had two phone lines or, in many areas of Europe, one phone line and an ISDN line. By using a broader range of frequencies over each of these two lines, the technology is able to get well above 1Gbps on both of them. But these lines are typically bundled together, which creates a degree of cross-talk between the signals. By using this crosstalk to carry information, the new hardware is able to boost the total capacity to up to 10Gbps. (Crosstalk between the two wires of a twisted pair is already being used in the same way in G.fast.)

Right now, the company has only two working demonstration units, one of which we got to have a look at. They rely on FPGAs and MATLAB code to process the signals, which are transmitted through a coil of paired copper wiring. The hardware is raw enough that the one we saw crashed during the demo, requiring the whole environment to be restarted. The existing implementation runs half-duplex, splitting the upsteam and downstream data between the channels. The engineers say they're working on getting full duplex running at 9Gbps.