Is there any relation between advertising interval, walking speed, and window size of moving average filter?

My beacons have advertisement interval of 330ms. I use iOS device to scan the advertisement packet whose scanning rate is 1 scan per second on average. I want to use the moving average filter to smooth the fluctuating RSSI values. Considering the walking speed as 1.2 m/s and the advertisement interval of 330 ms, what should be the size of a window in the moving average filter?