A method for optimizing power consumption for Narrowband Internet of Things devices, UEs, in idle mode using a coverage class specific paging configuration, where carriers for paging are partitioned by coverage class, whereas the coverage class specific paging configuration, broadcasted by a system information exchanged between the base station and the UE, is extended by an additional NRSRP rsrp-ThresholdPcch threshold, whereas the UE selects one carrier for paging with a Narrowband Reference signal received power (NRSRP) smaller than the rsrp-ThresholdPcch threshold or if a UE is not reachable the eNodeB expands a paging area for the considered UE stepwise into other paging coverage classes in order to reach the UE.