Researchers push 100-Gbits/sec over Category 7 copper

Engineering graduate students at Penn State University recently told the IEEE High Speed Study Group (www.ieee.org) that their research shows the possibility of sending digital data at 100-Gbits/sec over 100 meters of Category 7 copper cable.

“A rate of 100 gigabit over 70 meters is definitely possible, and we are working on extending that to 100 meters, or about 328 feet,” says Ali Enteshari, a PSU graduate student in electrical engineering. “However, the design of a 100-Gbit modem might not be physically realizable at this time.”

Using information on specifications and characteristics of cables from NEXANS(www.nexans.com), the Penn State researchers modeled the cable with all its attributes, including crosstalk. They then designed a transmitter/receiver equipped with an interference canceller that could transfer up to 100 gigabits using error correcting and equalizing approaches.

While fiberoptic cabling is typically used for high-speed connectivity, it has been deemed by some to be too costly for typical home networking or small business use. But copper cables have been limited by the distance they can transmit high-speed data without degradation of signal, necessitating the need for repeaters to capture, correct, or recover data and then resend it.

“What we are offering is a less expensive solution and one that is easier to build,” says Jarir Fadlullah, a graduate student in electrical engineering.

PSU researchers believe that in the not-too-distant future, chip circuitry technology will allow for a modem design that can handle 100-Gbit/sec speeds. Currently, says Mohsen Kavehrad, professor of engineering, modem chip design is at about 65 nanometers.

“We are providing a roadmap to the design of a high-speed modem for100 gigabits,” sums Enteshari concerning the Penn State study.

Kavehrad and student researchers did similar analysis on Category 5 cables in 2003.