Low-rate parallel scrambling techniques for today´s lightwave transmission

Parallel scrambling techniques enable low-rate realizations of high-speed scrambling processes in today´s lightwave transmission, which otherwise might be impossible due to technology limitations. Such parallel scrambling techniques are now available for frame synchronous scrambling (FSS), distributed sample scrambling (DSS), and self-synchronous scrambling (SSS), in bit-interleaved as well as byte-interleaved multiplexing environments. The objective of the article is to introduce the parallel scrambling techniques for FSS, DSS, and SSS, together with their applications to lightwave transmissions such as the SDH/SONET and the ATM network. It first considers the role of scrambling in digital transmission, and provides a brief description of the three scrambling techniques. Then it introduces the corresponding three parallel scrambling techniques, and finally demonstrates how they can be practically applied in low-rate scrambling processing of the SDH/SONET transmission signals, the cell-based ATM signals, and the SDH-based ATM signals