How are future frames used?

[alexgomezmotional]

I see in the leaderboards for detection camera-only on nuScenes Sparse4Dv3 offline is #1, and it notes that it also uses future frames as input.

how are future frames used?

[CrawlingD]

You can check Sparse4Dv3 Paper.
it said: "we adopt the multi-frame sampling approach from Sparse4Dv1 to fuse features from future frames"