Bit error rate measurements of 14,000 km 5 Gbit/s fibre-amplifier transmission system using circulating loop

An experimental technique was developed for measuring bit error rates in multi-thousand kilometre fibre amplifier systems using a circulating loop. A transmission distance of 14,300 km at 5 Gbit/s and 21,000 km at 2.4 Gbit/s was achieved using a non-return-to-zero pseudorandom data pattern. The bit rate distance product of the 5 Gbit/s result was 71 Tbit km/s.