Foreword1 Scope2 References3 Definitions and abbreviations4 General4.1 Overview4.2 Coordination between the protocols for 5GS mobility management and 5GS session management4.3 UE domain selection4.4 NAS security4.5 Unified access control4.6 Network slicing4.7 NAS over non-3GPP access4.8 Interworking with E-UTRAN connected to EPC4.9 Disabling and re-enabling of UE's N1 mode capability4.10 Interworking with ePDG connected to EPC4.11 UE configuration parameter updates4.12 Access traffic steering, switching and splitting (ATSSS)4.13 Support of NAS signalling using wireline access network4.14 Non-public network (NPN)4.15 Time synchronization and time sensitive communication4.16 UE radio capability signalling optimisation4.17 5GS mobility management in NB-N1 mode4.18 5GS session management in NB-N1 mode4.19 5GS mobility management in WB-N1 mode for IoT4.20 5GS session management in WB-N1 mode for IoT4.23 NAS over Non-Terrestrial Network4.24 Minimization of service interruption4.25 Support of MUSIM features5 Elementary procedures for 5GS mobility management5.1 Overview5.2 Behaviour of the UE in state 5GMM-DEREGISTERED and state 5GMM-REGISTERED5.3 General on elementary 5GMM procedures5.4 5GMM common procedures5.4.1 Primary authentication and key agreement procedure5.4.2 Security mode control procedure5.4.3 Identification procedure5.4.4 Generic UE configuration update procedure5.4.5 NAS transport procedure(s)5.4.6 5GMM status procedure5.4.7 Network slice-specific authentication and authorization procedure5.5 5GMM specific procedures5.5.1 Registration procedure5.5.2 De-registration procedure5.5.3 eCall inactivity procedure5.5.4 Authentication and key agreement procedure for 5G ProSe UE-to-network relay5.6 5GMM connection management procedures6 Elementary procedures for 5GS session management6.1 Overview6.1.1 General6.1.2 Types of 5GSM procedures6.1.3 5GSM sublayer states6.1.4 Coordination between 5GSM and ESM6.1.4a Coordination between 5GSM and SM6.1.5 Coordination for interworking with ePDG connected to EPC6.2 General on elementary 5GSM procedures6.3 Network-requested 5GSM procedures6.4 UE-requested 5GSM procedures6.4.1 UE-requested PDU session establishment procedure6.4.2 UE-requested PDU session modification procedure6.4.3 UE-requested PDU session release procedure6.5 5GSM status procedure6.6 Miscellaneous procedures7 Handling of unknown, unforeseen, and erroneous protocol data8 Message functional definitions and contents9 General message format and information elements coding9.1 Overview9.2 Extended protocol discriminator9.3 Security header type9.4 PDU session identity9.5 Spare half octet9.6 Procedure transaction identity9.7 Message type9.8 Message authentication code9.9 Plain 5GS NAS message9.10 Sequence number9.11 Other information elements9.11.1 General9.11.2 Common information elements9.11.3 5GS mobility management (5GMM) information elements9.11.4 5GS session management (5GSM) information elements9.12 3GPP specific coding information defined within present document10 List of system parametersA.1 Causes related to UE identificationA.2 Cause related to subscription optionsA.3 Causes related to PLMN or SNPN specific network failures and congestion/authentication failuresA.4 Causes related to invalid messagesB.1 Causes related to nature of requestB.2 Protocol errors (e.g., unknown message)C.1 Storage of 5GMM information for UEs not operating in SNPN access operation modeC.2 Storage of 5GMM information for UEs operating in SNPN access operation modeD.1 GeneralD.2 ProceduresD.3 UE policy re-assembly at the UED.4 VoidD.5 Message functional definition and contentsD.6 Information elements codingD.7 Timers of UE policy delivery serviceD.8 Handling of unknown, unforeseen, and erroneous UPDS dataD.8.1 GeneralD.8.2 Message too short or too longD.8.3 Unknown or unforeseen procedure transaction identityD.8.4 Unknown or unforeseen message typeD.8.5 Non-semantical mandatory information element errorsD.8.6 Unknown and unforeseen IEs in the non-imperative message partD.8.7 Non-imperative message part errorsD.8.8 Messages with semantically incorrect contentsD.8.8 Messages with semantically incorrect contents D.4 Void 24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 18Stage 3TS Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM