Sub-millisecond dynamic optical path setup in DWDM multi-mode switching networks

DWDM multi-mode switching network provides a unified approach to DWDM-based communications by allowing electronic packet switching (EPS), optical burst switching (OBS) and optical circuit switching (OCS) to be carried in the same network, and on the same router platform. In this paper, we present a sub-millisecond dynamic optical path setup scheme for the multi-mode switching router. More specifically, we devised a reconfigurable asymmetric optical burst switching (RA-OBS) scheduling scheme which integrates burst scheduling in the OBS mode, connection setup/teardown in the OCS mode, and channel reconfiguration in the EPS mode in a seamless fashion. The proposed scheme allows wavelengths to be dynamically shared among three different switching modes in real-time. The performance of the proposed integrated scheduler has been verified using OBS-ns2 simulator as well as in a hardware testbed. In particular, we have implemented the proposed integrated multi-mode scheduler in FPGA hardware in an optical switching testbed, and have demonstrated application triggered real-time sub-millisecond optical path setup. Another key contribution is that the proposed approach brings out the practical value of optical burst switching, which has stayed mostly in the theoretical regime in the past decade. We show that a truly dynamic optical network can be built with off-the-shelf optical components.