The IWG is discussing the time interval from door lock to initial warning, with options of 15, 25, or 30 seconds as specified in para. 6.4.1. Investigation of door vibration effects during closing at three speeds (strong 3 m/s, medium 2 m/s, weak 1.2 m/s) on a medium SUV showed door vibration diminishes around 10 seconds. The system requires at least 3 times respiration cycles for accurate child detection judgment to reduce false-positive warnings in the field. A 25 seconds delay is recommended to allow appropriate time for accurate detection while accounting for vehicle vibration disturbance.