This paper describes the 5B6B coding strategy and synchronous principle as well as the calculation of synchronous performance by laying the key emphasis on "word disparity"

which was first employed in China as transmission pattern on Wuhan 8 Mb/s Optical Fiber Communication System. Results show that the synchronous reliability is good. The occurence of misalignment due to BER = 10

-3

is once every 1.2×10

25

years on average. The alignment aquisition time is 466 μs

and a misalignment can be detected in 59 μs with a probability of 0.99.