This paper outlines the overall line coding requirements for 140 Mb/s optical fibre transmission system operating at a wavelength of 1.3μm. It was concluded that choice lay between 5B6B and 7B8B alphabetic block codes. Consequently, a detailed investigation of the parameters of both codes were carried out and a comparison between them was given. It was also concluded that although the difference between 5B6B and 7B8B codes is slight, 5B6B code offers advantage in terms of circuit complexity and power consumption.
G A.M. Abbas,
L. J. Rysdale,
"Line Coding For 140 Mb/S Optical Fibre Digital Line Systems", Proc. SPIE 0468, Fibre Optics '84, (15 August 1984); doi: 10.1117/12.941661; https://doi.org/10.1117/12.941661