Field experiment of all-optical WDM ring network up to 70-Gb/s capacity employing 198-km installed dispersion shifted fiber

This paper presents a successful field experiment of an 8-wavelength WDM ring network with all-optical ADM nodes using a regional fiber cable loop in Japan. The effect of laser frequency misalignment is also presented. In this paper we report bit-rate upgradability ( 8-Gb/s to 70 Gb/s) of the above field test network system. In addition, the frequency detuning tolerance of the high bit-rate lightwave signals with the cascaded optical add drop multiplexer (OADM) nodes in a field enviroment is also measured and discussed.