A system including at least two distally separated devices that are in wireless communication with each other, wherein at least one of the two devices is provided with a warning mechanism configured to indicate an existing or imminent interruption or disturbance of communication. The inventive system may include a base unit and at least one mobile medical or pharmaceutical device in unidirectional communication or bidirectional communication with the base unit. A method for monitoring wireless communication between at least two devices is encompassed, wherein at least one of the two devices indicates an existing or imminent interruption or disturbance of the wireless communication by changing a type of the communication signal transmission.