The invention relates inter alia to a method performed by at least one apparatus, said method comprising: obtaining radiation signal data comprising results of measurements on radiation signals received at a mobile device and emitted by a positioning support device covering one or more signal areas by sweeping a striped band of radiation across said one or more signal areas; and determining a position of said mobile device within a signal area of said one or more signal areas at least based on said radiation signal data. The invention also relates to a positioning support device for supporting determining of positions of mobile devices in one or more signal areas, comprising: a radiation source covering said one or more signal areas by sweeping a striped band of radiation across said one or more signal areas.