Development of an Optical-Burst Switching Node Testbed and Demonstration of Multibit Rate Optical Burst Forwarding

With the rapid growth in Internet traffic, demands for a high-capacity switching network with low end-to-end latency are being felt. Optical-label switching, in general, and optical burst switching (OBS), in particular, can provide such a solution with realizable device technology. This paper is a summary of the Photonic Network Project undertaken in Japan, wherein we have implemented a prototype OBS-node testbed based on novel device concepts. A three-node OBS core testbed and edge nodes operating over payload bit rates of 10 Gb/s to 40 Gb/s were developed, demonstrating feasibility of the OBS concept. We report newly developed key photonic building blocks of the OBS node, namely: a fast matrix switch based on lead-lanthanum-zirconate-titanate, a bit-rate transparent tunable wavelength converter based on a monolithically integrated wavelength converter; a fast tunable wavelength laser diode; compact arrayed waveguide amplifiers; and athermal, flat-top multiplexers. Together, with an optical-label recognition scheme implemented in a field-programmable gate array (FPGA), we have integrated the building blocks into an optical burst switching-node prototype that can potentially be scaled up to 64 times 64 ports. We have confirmed error-free optical burst forwarding for more than 10 hops in an OBS network with variable length, asynchronous burst arrival. We have also achieved a mixed bit-rate optical burst forwarding and contention resolution with wavelength conversion. We have also demonstrated coordination of OBS with upper-layer protocols by implementing an Ethernet-frame-to-optical-burst converter edge node, which successfully transmitted real application data over the OBS network at 40 Gb/s. Similar results were achieved in a multinode testbed under the field fiber environments, with a low frame error rate of less than 1 times 10^-6.