Research addresses 100 Gbits/s over 100-m Category 7 cable

Research addresses 100 Gbits/s over 100-m Category 7 cable

Working with cable manufacture Nexans, research engineers at Penn State University (State College, PA) are examining the possibility of sending digital data at a rate of 100 Gbits/s over 100 m of Category 7 copper cable. Cat 7 cable is typically used for connecting computers in home or small-office networks, and being able to provide such speeds over copper cable enables a less expensive solution — and one that is easier to build — compared with fiber.

“A rate of 100 Gbits over 70 m is definitely possible, and we are working on extending that to 100 m, or about 328 ft,” said Ali Enteshari, graduate student in electrical engineering who presented the team’s methods to the IEEE High Speed Study Group in November 2007. “However, the design of a 100-Gbit modem might not be physically realizable at this time as it is technology limited.”

All transmission cables are limited by the distance they can transmit data without degradation of the signal. Before errors and interference make the signals nonrecoverable, cable systems use repeaters 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.

Researchers modeled the cable with all its attributes including modeling crosstalk. They then designed a transmitter/receiver equipped with an interference canceller that could transfer up to 100 Gbits/s using error-correcting and equalizing approaches.

Researchers believe that two or three generations in the future, the technology of chip circuitry will allow these modem designs to be built. For more information, visit http://live.psu.edu/story/27265.

Ralph Raiola