Engineers at Pennsylvania State University in the US are attempting to achieve data speeds of 100 gigabits per second over Cat 7 copper cables. If successful, it could pave the way for copper cables able to handle the same data rates as more expensive fibre optic links.
"A rate of 100gbps over 70 metres is definitely possible, and we are working on extending that to 100 metres," said Ali Enteshari, graduate student in electrical engineering and part of the research team.
These cables are used to connect computers within a room or a building, or to create parallel computing systems.
Although the long-distance lines of most internet systems are glass fibre optic cables, which offer fast data transfer, copper cable is generally used for short distances.
All transmission cables are limited by the distance they can transmit data without degradation of the signal. Before errors and interference make the signals non-recoverable, cable systems use repeaters - which are similar to computer modems - to capture, correct or recover data, and resend it. The distance between repeaters depends on the cable and the approach used by the modem to correct errors.
"What we are offering is a less expensive solution and one that is easier to build," said Jarir Fadlullah, a graduate student on the Pennsylvania research team.
Using information on specifications and characteristics of the cables, the researchers modelled the cable with all its attributes, including modelling crosstalk. They then designed a transmitter/receiver equipped with an interference canceller that could transfer up to 100gbps using error correcting and equalizing approaches.
"However, the design of a 100gbps modem might not be physically realisable at this time as it is technology limited. We are providing a roadmap to design a high speed modem for 100gbps," said Enteshari.