Train Video Data Retention via Multi-Parameter Deletion Logic

The patent changes the deletion criterion from a single parameter (validity period) to multiple parameters including number of presentations, time period since last presentation, and video data volume. This multi-parameter approach allows more accurate identification of video data that can be safely deleted while retaining data that should be preserved, thereby improving storage efficiency without sacrificing storage capacity.

The patent performs preliminary assessment of video data deletion candidates before deletion occurs, using multiple criteria to determine which data should be retained. This preliminary action ensures that video data likely to be retransmitted during boarding and alighting is preserved in storage, eliminating the need for time-consuming retransmissions and reducing time loss during these operations.

The patent applies different retention policies to different video data based on their individual characteristics such as volume, presentation frequency, and time since last presentation. Instead of uniform deletion based solely on validity period, the system selectively retains or deletes specific video data files, allowing high-quality large-volume advertisements to be preserved when necessary while freeing storage space for other purposes.