 the message support relating to the establishment of the connection. RLC mode Transport Logical channel channel Physical channel UL-SCH PUSCH SetupRequest DL-SCH PDSCH SetupReject UL-SCH PUSCH SetupComplete Table 9.4. Support for messages relating to the connection establishment The SetupRequest message is transmitted by the mobile to initiate the connection establishment procedure. The message contains the following pieces of information: RRCSetupRequest ue-Identity establishmentCause ue-Identity: this element of information indicates the identity of the mobile, the 5G-S-TMSI identity if the mobile is attached or a 39-bit random value otherwise. 5G-NR Radio Interface - Radio Access Procedure establishmentCause: this element of information indicates the cause of the connection establishment as: - emergency call; - priority call; - mobile terminated call MT; - mobile originating call (MO-Data MO-VoiceCall, MO-VideoCall, MO-SMS); - mobile originating signaling (MO-Signaling); - priority multimedia service (mps-PriorityAccess); - critical service mission (mcs-PriorityAccess). The RRC Setup message is the response from the gNB entity to accept the request to establish the connection. The RRC Setup message is transmitted to establish the SRB1 bearer and carries the information for the configuration of the radio bearer of the master cell. The RRC Setup message is used to configure the parameters of the PHY, MAC, RLC, PDCP and SDAP layers, and contains the following information elements: RRCCSetup rrc-TransactionIdentifier radioBearingConfig CellGroupConfig rrc-TransactionIdentifier: this element of information provides the transaction ID. radioBearerConfig: this element of information provides the characteristics of the SRB1 or SRB3 media and the DRB media. The configuration changes the parameters of the PDCP sublayer. cellGroupConfig: this element of information provides the RLC, MAC and PHY parameters for the configuration of a secondary cell. The secondary cell corresponding to carrier aggregation or dual connectiv