Upgrading Legacy Long-Haul WDM Systems Through Unbalancing the Proportion of 1s and 0s in the Transmitted Data

ABSTRACT

We present experimental results for wavelength-division multiplexed (WDM) transmission performance using unbalanced proportions of 1s and 0s in pseudo-random bit sequence (PRBS) data. This investigation simulates the effect of local, in time, data unbalancing which occurs in some coding systems such as forward error correction when extra bits are added to the WDM data stream. We show that such local unbalancing, which would practically give a time-dependent error-rate, can be employed to improve the legacy long-haul WDM system performance if the system is allowed to operate in the nonlinear power region. We use a recirculating loop to simulate a long-haul fibre system.

KEYWORDS:

• Long-haul undersea systems
• Optical fibre networks
• Submarine cable networks
• WDM systems

ACKNOWLEDGMENTS

The authors thank Stuart Barnes, Steve Webb, Stephen Desbrulais, John Ellison, Joerg Schwartz, Robin Ibbotson and Paul Harper for their helpful discussions and suggestions during the course of this work.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Mousaab M. Nahas

Mousaab M. Nahas received his BSc degree from the University of Jordan in 1999 and MSc degree from Aston University in 2002. His specialization is communications engineering. In 2003, he joined the Photonics Research Group at Aston University and received his PhD degree in optical fibre communications in 2007. He worked in telecommunications industry between 2007 and 2009. In 2009, he joined King Abdulaziz University in KSA and worked as an assistant professor in electrical engineering until 2014. Since 2015, he has been working in the Electrical and Computer Engineering Department at the University of Jeddah in KSA. Dr. Nahas's main research interest is upgrading legacy WDM communication systems using different techniques including data patterning and modulation formats. He is also interested in line monitoring techniques for legacy optically amplified long-haul undersea systems.

E-mail: [email protected]

Keith J. Blow

Keith J. Blow received his BA degree in physics and theoretical physics from Cambridge University in 1978. He then joined the Theory of Condensed Matter Group of the Cavendish Laboratory and received his PhD degree for studies on Deep Impurities in Semiconductors in 1981. He joined the optics division of BT Labs in 1981 and worked on the theory of non-linear optical propagation effects in fibres, principally solitons. This work developed into optical switching and the first demonstration of soliton switching in non-linear optical loop mirrors. In 1990 he set up a group working on quantum optical properties and non-linear spatial optics as well as continuing work on all-optical processing which is currently concerned with ways of using and manipulating the information that can be sent over the enormous bandwidth of optical fibres. In 1999 he moved to the Photonics Research Group at Aston University to continue working on optical networks and optical computation. In 2003 he formed the Adaptive Networks Communications Research Group to study ad-hoc sensor networks, applications of dynamic hardware and mobile systems.

E-mail: [email protected]