A reference configuration of the transmission chain is shown in GSM 05.01. According to this reference configuration@ this European Telecommunication Standard (ETS) specifies the data blocks given to the encryption unit. It includes the specification of encoding@ reordering@ interleaving and the stealing flag. It does not specify the channel decoding method. The definition is given for each kind of logical channel@ starting from the data provided to the channel encoder by the speech coder@ the data terminal equipment@ or the controller of the MS or BS. The definitions of the logical channel types used in this technical specification are given in GSM 05.02@ a summary is in annex 1.