155.52 Mb/s Data Transmission on Data Grade Unshielded Twisted Pair Copper Cable
William E. Stephens
David Sarnoff Research Center, CN 5300, Princeton, NJ 08543
About The Talk
We demonstrate the feasibility of transmitting 155 Mb/s SONET/ATM signals using
different line codes (Non-Return to Zero (NRZ), Multi-Level Transmit - 3 Levels
(MLT3), Binary Partial Response - Class 1 (BPR1) and Binary Partial Response -
Class 4 (BPR4)) over distances greater than 100 meters on data grade (EIA/TIA
568 Category 5 specification) unshielded twisted pair copper cable. We measured
RF emission characteristics for each line code and examined the effect of
alternative termination schemes on radiative emissions. We concluded that
common mode terminations produce consistantly lower radiated emissions than quad
terminations or balun terminations. We also showed that emission levels are
positively correlated with the spectrum of the transmitted signal. For a given
transmit level at 155Mb/s, MLT3 had the lowest emissions between 30 to 50 MHz
while BPR1 had the lowest emissions above 60 MHz. The emissions with BPR1 and
MLT3 were 4 to 20 dB (13 dB typical) and 8 to 13 dB (10 dB typical) below NRZ
levels, respectively. We also measured the BER sensitivity to injected noise
and pseudo-random data sequence length. The ISI penalty was greater than 2 dB
with conventional ``two-zero'' forward equalization, while NRZ and BPR1
exhibited a 10-10 Bit Error Rate floor due to baseline wander associated with
transformer coupling. Both effects could be removed with decision feedback
equalization. MLT3, BPR1 and BPR4 offer 5 to 15 dB better radiated emission
performance over NRZ at 155 Mb/s, although implementation complexity is greater.
About The Speaker
WILLIAM E. STEPHENS, Ph. D., is the Head of the Wireless and ATM Networking
Group at the David Sarnoff Research Center in Princeton, New Jersey. His
group is studying wireless access technologies along with interoperability of
Asynchronous Transfer Mode (ATM) packet local area networks with the evolving
broadband public network. Prior to joining Sarnoff, Dr. Stephens was at
Bellcore as the Director of the High-Speed Switching and Storage Technology
Group. There, his group studied the interoperability, control, and management
of ATM packet networks. Prior to joining Bellcore, he was section head for a
TRW group researching transmission of microwave signals over analog fiberoptic
links. While with TRW, he was involved in research on fiberoptic
communications, high-power single longitudinal mode laser diodes, and optical
signal processing. He received the Ph. D. degree from the University of
Southern California. For his dissertation, he demonstrated one of the first
hybrid optical-digital computers. Dr. Stephens has over 40 publications and
one patent in the field of communications and networking. He has served on
several technical program committees, including IEEE GLOBECOM and IEEE
Electronic Components and Technology Conference (ECTC) and has served as Guest
Editor for 2 issues of the IEEE Journal on Selected Areas in Communications.
He is a senior member of the IEEE, and a member of OSA, SPIE, Sigma Xi, Tau
Beta Pi, and Eta Kappa Nu.