A request to establish video communication with a recipient associated with multiple communication devices is received. The propulsion drive comprises at least one first propeller drive, which rotates the first propeller and by which the propulsion power andor rotating speed of the first propeller, and a second propeller drive, by which the second propeller is rotated and controlled. The trench shape of the photosensor provides the photosensitive element with an increased surface area compared to a flat photosensor occupying a comparable area on a substrate. Lengthwise perforations formed down substantially a middle of the transparent cover and separate the transparent cover first side from the transparent cover second side.