What is DSC Call Duration and at what interval will you repeat DSC Distress Alert?

A single call on MF/HF DSC varies between 6.2 – 7.2 seconds while on VHF it varies between 0.45 – 0.63 seconds.

To repeat a DSC Distress alert we can do it after 3.5 to 4.5 minutes from the beginning of the initial call.