(TA). 3) The mobile sends its session establishment request to the eNB entity in an RRC ConnectionRequest message. In this request, the mobile sends its C-RNTI radio identity, its S-TMSI core network identity or a random number and the object of its request (session request: Mobile Originating Signaling). 4) The eNB entity allocates a radio dedicated signaling Radio Bearer (SRB1) to the mobile via the RRC ConnectionSetup message. The downlink (DL) and uplink (UL) radio resources are controlled by the base station. On receipt of the RRC ConnectionSetup message, the mobile will use the dedicated radio resources to transmit the content of the NAS signaling message. 5) The mobile notifies the base station of the establishment of the SRB1 signaling bearer via the RRC ConnectionSetupComplete message and transmits the NAS information (e.g. an attachment request, a service request, an SMS) in the DedicatedInfoNAS field of the RRC ConnectionSetupComplete message. The eNB entity transmits the session establishment request to the MME entity. The MME provides the following information to the eNB: - E-RAB radio support parameters, including QoS parameters and tunnel termination with the SGW (Serving Gateway) entity; - the radio capabilities of the mobile; - the security context of the mobile to secure radio access (the eNB security key). The eNB entity will activate the DRB bearer by setting up: 6) 7) a procedure to secure the radio link (securing the AS access stratum); 8) 9) a reconfiguration of the RRC connection. During this request, the eNB entity transmits the measurement configuration. At the end of this procedure, the mobile can securely exchange data with the eNB entity. The eNB entity confirms the establishment of the DRB radio bearer to the MME entity SO that the latter can finalize the establishment of the tunnel between the eNB entity and the SGW entity handling the 4G core network traffic. NG-RAN Network - Procedures PRACH (Preamble) PDCCH (RA-RNTI)/PDSCH MAC RAR RRC ConnectionRequest RRC ConnectionSetup RRC Con