Date Added: May 2009
In reconfigurable optical networks, the lightpaths are dynamically adjusted by the use of Reconfigurable Optical Add/Drop Multiplexers (ROADMs). Reconfiguration also requires tunable transmitters and receivers (transponders). Fully reconfigurable ROADMs that can add/drop any wavelength to any port (i.e., ROADMs with colorless ports) use tunable transponders at the add/drop ports. It is shown in that Limited Tunable Transponders (LTTs) give similar blocking performance as widely tunable transponders. OEO conversion is enabled by dropping a certain wavelength at an intermediate node and then adding another wavelength. With such conversions, a lightpath does not need to be end-to-end wavelength-continuous and is said to use multi-hopping.