Apparatus and method for small-scale motion sensing

An apparatus for motion detection according to an embodiment is provided. The apparatus comprises a phase difference determiner (110) configured for determining a phase difference for each of one or more signal connections between a transmitter and a receiver of a cellular network. Moreover, the apparatus comprises a motion detector (120) configured for detecting a movement depending on the phase difference of each of the one or more signal connections. Each of the one or more signal connections is a connection between the transmitter and the receiver for transmitting a signal of the signal connection from the transmitter to the receiver within the cellular network. The signal is a signal used for transmitting control data used for controlling user data communication within the cellular network, or is a signal used for supporting user data communication within the cellular network. The phase difference for each of the one or more signal connections indicates a difference between a first phase value of the signal of the signal connection received at the receiver of the signal connection at a first point-in-time and a second phase value of the signal of the signal connection received at the receiver of the signal connection at a different second point-in-time.