Embodiments of the present disclosure provide apparatus, methods and computer readable storage mediums for configuring resources for positioning reference signals. A method comprises determining a second set of resource configuration for positioning reference signal (PRS) mapping to resource elements in the second set, wherein the second set is an extension of the first set of resource configuration for PRS mapping with additional resource elements. The method further comprises transmitting configurations of at least one of the first set and the second set, to configure PRS transmission according to the first set or the second set.