The OTUk frame rate can be concluded based on OTU1, OTU2, and OTU3 frame rates.

The formula to calculate the OTUk frame rate is: OTUk frame rate = 255 / (239 - k) × STM-N frame rate. Here, "k" represents the OTUk version index, and STM-N is the synchronous transport module rate. This formula derives from the OTN standard, adjusting the frame rate according to the version and allows synchronization with underlying SDH/SONET rates. HCIP-Transmission materials provide this formula for engineers to correctly understand and calculate transmission rates for different OTN layers.