Evaluations of physical and optical path level hierarchical networks to implement optical fast circuit switching

We propose an efficient network architecture to implement optical fast circuit switching. Future bandwidth abundant services such as Ultra High Definition Television (UHDTV), lambda-leased line services, and layer-one optical VPNs will generate less-bursty traffic that will fill wavelength path capacity. To realize effective optical fast switching networks, we introduce a hierarchical structure that combines physical network and optical path levels. A higher physical layer network (transit network) bridges several lower layer networks (local networks). The optical path layer is divided into two layers; a waveband path (a group of wavelength paths), and wavelength path layer. The transit networks employ large granular optical paths, waveband paths. The transit network creates an adaptive virtual topology that can efficiently carry wavelength path connection requests between lower layer network nodes. Numerical experiments show that the proposed hierarchical network greatly reduces the necessary number of optical switch ports at the blocking probability equivalent to that of the single layer network. The effectiveness of the proposed architecture are confirmed for various network sizes.