The present invention relates to a method for determining whether a wireless device is reachable in a cell served by a radio network node. The method is performed in the radio network node. The wireless device is in connected mode in the cell and applies DRX. The method comprises allocating (510) a dedicated random access preamble to the wireless device. The dedicated random access preamble is to be transmitted by the wireless device to indicate that the wireless device is reachable in the cell. The method further comprises transmitting (520) an indicator of the dedicated random access preamble to the wireless device, and monitoring (530) for the dedicated random access preamble from the wireless device. The method also comprises determining (540) that the wireless device is reachable when receiving the dedicated random access preamble from the wireless device.