Methods, apparatus and systems for wireless motion monitoring to ensure security are described. In one example, a described system comprises: a transmitter configured for transmitting a first wireless signal through a wireless multipath channel of a venue; a receiver configured for receiving a second wireless signal through the wireless multipath channel; and a processor. The second wireless signal differs from the first wireless signal due to the wireless multipath channel and a motion of an object in the venue. The processor is configured for: obtaining a time series of channel information (TSCI) of the wireless multipath channel based on the second wireless signal; computing a spatial-temporal information (STI) based on the TSCI; monitoring the motion of the object based on the TSCI and the STI; performing a task based on the monitoring; and generating a response based on the task.