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The recent collaboration between Nexans and Penn
State on a paper entitled “40/100 Gbps Transmission Over
Copper, Myth and Realities” resulted in a best paper
award at DesignCon 2009. The paper was presented in the
category “High-Speed and RF Design.
The paper was presented by Ali Enteshari, a Ph.D.
candidate in the department of Electrical Engineering at
the Pennsylvania State University, University Park. His
faculty advisor Dr. Mohsen Kavehrad had been contracted
by Nexans, more specifically, the Data Communications
Competency Center of Nexans, to evaluate the theoretical
possibilities of transmitting 40/100Gbps data rates over
Category 7A cabling.
Abstract
This paper focuses on
assessment and design of transmission systems for
distribution of digital signals over standard
Category-7A copper cables at speeds beyond -10Gbps. The
main contribution of the paper is on the technical
feasibility and system design for data rates of 40 and
100Gbps over copper. Based on capacity analysis and rate
optimization algorithms, system parameters are obtained
and the design implementation trade-offs are discussed.
The simulation results confirm that with the aid of
Decision-Feedback Equalizer and powerful coding
techniques, e.g. TCM or low-density parity-check (LDPC)
code, 40Gbps transmission is feasible over 50m of CAT-7A
copper cable. These results also assure that 100Gbps
transmission can be achieved over 15m of the same copper
cable.
Conclusion
The results of this
paper confirm the technical feasibility of beyond 10Gbps
high-speed transmission over standard Category 7A copper
wire. The assessment has revealed that CAT-7A cables
are, theoretically, capable of delivering data streams
at a speed of 40Gbps over 50 meters thanks to their
excellent shielding and engineering design. Also, based
on our modeling and analysis, the maximum achievable
rate over 20 meters of cable is well above 100Gbps.
However, with various degrees of DSP, the objective of
running 100GBASE-T over CAT-7Acable can be achieved with
some effort by the silicon vendors, probably in the next
generations of CMOS technology.
We conclude that 40GBASE-T is practical over 50
meters of CAT-7A cable, and this is within the realm of
expectation of current objectives of IEEE 802.3
standards committee.
Click here to read the award-winning paper: 40/100 Gbps Transmission Over Copper:
Myths and Realities
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