A plunge base router for use in an upright and an inverted position is disclosed. For each cell member in said neighbor cell set, handover statistics reflecting how frequent said cell member is involved in handovers aiming at modifying active sets including at least said first cell to include said cell member are registered. The array of light sources is configured to generate beams of coherent light with a substantially uniform distribution of the beams of coherent light in an area on a surface of an object in the area that results in a number of speckle patterns in light reflected from the surface of the object in the area in response to the beams of coherent light in the area.