1. An apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus to perform at least the following: to conduct with at least one communication network control element a communication by using a demodulation reference signal based communication mode for signals received from the at least one communication network control element; to generate in the demodulation reference signal based communication mode at least one predefined scrambling sequence of a demodulation reference signal, wherein each of the at least one scrambling sequence comprises a set of calculation parameters being specific for the respective scrambling sequence, wherein the set of calculation parameters is configurable during the at least one communication on the basis of configuration information received from the at least one communication network control element; and to select, for initializing each of the at least one scrambling sequence before receiving the configuration information, at least one predetermined default value selectable from a set of predetermined default values for the set of calculation parameters in each of the at least one scrambling sequence, wherein the at least one predetermined default value is determined by using an identification element identifier of a terminal device as a parameter of a preset algorithm.