Hitless wavelength add-drop using a novel signaling protocol combined with hitless switching techniques

We have proposed and experimentally demonstrated a novel scheme for hitless wavelength add-drop. Our scheme will enable services such as TDM channel provisioning, cross-connections between wavelengths and monitoring without service interruption or downtime, important for future networks with frequent reconfiguration. We have described a simple network protocol and the modifications required to traditional SONET network elements to perform hitless add-drop. Moreover, our testbed successfully confirmed hitless network reconfiguration: ZERO bit error rate during wavelength add-drop.