A wireless communication device in a 3GPP NB-IoT wireless communication network operates during an inactivity period of an eDRX cycle. An activation procedure comprises calculating, in a time reference frame inherent to the wireless communication device, an earliest and a latest point in time for obtaining a narrowband master information block (MIB-NB) transmitted by a network node in a narrowband physical broadcast channel (NPBCH) during a single NPBCH transmission time interval. Between the calculated earliest point in time and latest point in time, radio receiver circuitry is activated in the wireless communication device and at least one radio subframe comprising the NPBCH is received and decoded. By this decoding, the MIB-NB is obtained, from which a system frame number (SFN) is read. A communication procedure then comprises activating the wireless communication device according to the eDRX cycle, and communicating, in a designated time interval as determined by the SFN, with the network node.