BS PD IEC/TR 62343-6-9:2015, which is a Technical Report, describes a study of the impact of WSSdynamic crosstalk on the optical network and includes dynamic crosstalk measurementexamples for three types of WSS. The generating mechanism and the generation factor ofdynamic crosstalk in WSS are clarified, and the evaluation of same-channel crosstalk anddifferent-channel crosstalk is shown to be necessary.