If you think copper wiring is ready to be put out to pasture as far as Net speeds are concerned, Bell Labs' new technology may delay that day. The famed R&D facility has developed a technique to transmit data over copper as fast as 10 gigabits per second.
The prototype technology is called XG-FAST, and it is also demonstrating how existing copper networks can handle 1 gigabit-per-second speeds up and down.
Bell Labs, the research arm of Alcatel-Lucent, describes the work as "a major breakthrough for copper broadband," because copper-to-the-home systems could provide speeds equal to that of fiber-to-the-home systems. Rewiring the last leg of most systems involves the arduous tasks of redoing the copper wiring to and inside the home or office, with fiber being delivered to the curb. Enabling very high speed transmissions on copper could dramatically remove that bottleneck.
XG-FAST is a version of the G.fast technology standard that is under final review by the International Telecommunication Union. G.fast is expected to become available in the marketplace sometime next year, using a frequency range for data transmission of 106 MHz. This can accommodate broadband speeds as high as 700 Mbps over a distance of 100 meters. G.fast/phase 2, using a frequency range of 212 MHz, can deliver 1.25 Gbps in one direction, over 70 meters.
XG-FAST, on the other hand, employs an increased frequency range as high as 500 MHz to handle faster speeds, but over shorter distances. The 1 Gbps up-and-down speeds were achieved on a single copper pair over 70 meters, with a frequency range of 350 MHz. Ten Gbps used two pairs, which is known as "bonding," over a 30-meter distance.
These results, the labs said, show that the key factors governing broadband speeds over copper are distance and frequency.
As is indicated by Bell Labs' results, the longer the distance covered by the copper connection, the slower the speed because of attenuation. The wider the frequency range, the faster the speed that can be reached. However, the catch is that higher frequencies attenuate more quickly than lower ones, so there is a diminishing return as frequency range increases.
'Ten Times Better'
Other factors can include cross-talk between cables and the quality/thickness of the cable.
Bell Labs President Marcus Weldon said in a statement that the labs aim to achieve "breakthroughs that are ten times better than [what is] possible today." He added that this demonstration of 10 Gbps over copper "is a prime example [that] by pushing technology to its limits, operators can determine how they could deliver gigabit services over their existing networks."
While this research shows that the last leg of copper to the home or office could still support very high transmission speeds, the effort may also signal that the end of the road is coming for copper. Ten Gbps could be the upper limit of what is possible on copper, and many copper-based systems are reaching the physical limits of their lifespans.