This part of IEC 62343 provides a performance specification template for wavelength selective switches. The object is to provide a framework for the preparation of detail specifications on the performance of wavelength selective switches. Additional specification parameters are often included for detailed product specifications or performance specifications if necessary. However, specification parameters specified in this document are not removed from the detail product specifications or performance specifications. The technical information regarding wavelength selective switches and their applications in DWDM systems with single-mode fibres are described in IEC TR 62343-6-4.