The invention relates to a wireless network comprising a radio access network and a plurality of terminals which are each provided for encoding certain data to be transmitted and for forming a key in the same manner in dependence on a first and a second frame number for a connection to be set up or to be reconfigured between the radio access network and a terminal. The first frame number depends on the periodically changing number of the radio frame used for the data transmission and the value of the second frame number depends on the first frame number. Based on the value of the first frame number the terminal and/or the radio access network is provided for ascertaining whether a time delay is to take place in the formation of the second frame number in the radio access network.