Optical path cross-connect node architectures for photonic transport network

This paper explores the optical path cross-connect (OPXC) node architectures that are essential components of the optical path network. Optical path technologies will play a key role in the development of the platform on which the future bandwidth abundant B-ISDN should be created. This paper highlights the wavelength path (WP) and the virtual wavelength path (VWP) technologies, both of which can greatly enhance the path layer capability and the efficiency of network failure restoration. The OPXC, which handles optical paths, is constructed with an optical switching network. Various WDM-based switching networks, which are aimed at LAN applications, have been reported. On the other hand, few WDM-based switching networks for OPXC systems, which are applicable to the nationwide transport network, have been proposed. In this paper, we elucidate the functional conditions required to construct OPXC nodes for WP and VWP global networks. Next, we assess switching network architectures for their applicability to the transport network. It is shown that the OPXC architecture based on DC-switches (delivery and coupling switches) is superior to the other OPXC architectures in terms of optical losses, modularity, and upgradability. Finally, detailed evaluations of the DC-switch-based OPXC node are presented that confirm its feasibility.