Inter-network interface for photonic transport networks and SDH transport networks

To realize a really effective photonic transport network, we must develop the network node interface (NNI) structure and the inter-network interface (INI) for the WDM optical path transport network. This paper proposes the NNI structure for the WDM optical path transport network that is defined as the optical transport module (OTM), and proposes the INI structure between the optical path transport network and the SDH transport network. The proposed INI structure can be developed with minimum modification from the existing SDH line-terminal system. Therefore, the economical hardware development and the economical and smooth introduction of the WDM optical path transport network become possible.