ETSI TS 123 501 V17.15.0 (2026-01)

5G; System architecture for the 5G System (5GS) (3GPP TS 23.501 version 17.15.0 Release 17)

RTS/TSGS-0223501vhf0

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 2 - Architecture
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 20-Jan-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
5G;
System architecture for the 5G System (5GS)
(3GPP TS 23.501 version 17.15.0 Release 17)

3GPP TS 23.501 version 17.15.0 Release 17 1 ETSI TS 123 501 V17.15.0 (2026-01)

Reference
RTS/TSGS-0223501vhf0
Keywords
5G
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ETSI
3GPP TS 23.501 version 17.15.0 Release 17 2 ETSI TS 123 501 V17.15.0 (2026-01)
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ETSI
3GPP TS 23.501 version 17.15.0 Release 17 3 ETSI TS 123 501 V17.15.0 (2026-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 19
1 Scope . 20
2 References . 20
3 Definitions and abbreviations . 25
3.1 Definitions . 25
3.2 Abbreviations . 31
4 Architecture model and concepts . 34
4.1 General concepts . 34
4.2 Architecture reference model . 35
4.2.1 General . 35
4.2.2 Network Functions and entities . 36
4.2.3 Non-roaming reference architecture . 37
4.2.4 Roaming reference architectures . 40
4.2.5 Data Storage architectures . 44
4.2.5a Radio Capabilities Signalling optimisatio n . 45
4.2.6 Service-based interfaces . 46
4.2.7 Reference points . 47
4.2.8 Support of non-3GPP access . 50
4.2.8.0 General . 50
4.2.8.1 General Concepts to Support Trusted and Untrusted Non-3GPP Access . 50
4.2.8.1A General Concepts to support Wireline Access . 51
4.2.8.2 Architecture Reference Model for Trusted and Untrusted Non-3GPP Accesses . 52
4.2.8.2.1 Non-roaming Architecture . 52
4.2.8.2.2 LBO Roaming Architecture . 53
4.2.8.2.3 Home-routed Roaming Architecture . 55
4.2.8.3 Reference Points for Non-3GPP Access . 57
4.2.8.3.1 Overview . 57
4.2.8.3.2 Requirements on Ta . 58
4.2.8.4 Architecture Reference Model for Wireline Access network. 58
4.2.8.5 Access to 5GC from devices that do not support 5GC NAS over WLAN access . 59
4.2.8.5.1 General . 59
4.2.8.5.2 Reference Architecture . 60
4.2.8.5.3 Network Functions . 60
4.2.8.5.4 Reference Points . 60
4.2.9 Network Analytics architecture . 61
4.2.10 Architecture Reference Model for ATSSS Support . 61
4.2.11 Architecture for 5G multicast-broadcast services . 62
4.2.12 Architecture for Proximity based Services (ProSe) in 5GS . 62
4.2.13 Architecture enhancements for Edge Computing . 62
4.2.14 Architecture for Support of Uncrewed Aerial Systems connectivity, identification and tracking . 63
4.2.15 Architecture to support WLAN connection using 5G credentials without 5GS registration . 63
4.3 Interworking with EPC . 64
4.3.1 Non-roaming architecture . 64
4.3.2 Roaming architecture . 65
4.3.3 Interworking between 5GC via non-3GPP access and E-UTRAN connected to EPC . 67
4.3.3.1 Non-roaming architecture . 67
4.3.3.2 Roaming architecture . 68
4.3.4 Interworking between ePDG connected to EPC and 5GS . 70
4.3.4.1 Non-roaming architecture . 70
4.3.4.2 Roaming architectures . 71
4.3.5 Service Exposure in Interworking Scenarios . 73
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4.3.5.1 Non-roaming architecture . 73
4.3.5.2 Roaming architectures . 74
4.4 Specific services . 75
4.4.1 Public Warning System . 75
4.4.2 SMS over NAS . 75
4.4.2.0 General . 75
4.4.2.1 Architecture to support SMS over NAS . 75
4.4.2.2 Reference point to support SMS over NAS . 77
4.4.2.3 Service based interface to support SMS over NAS . 77
4.4.3 IMS support . 77
4.4.4 Location services . 78
4.4.4.1 Architecture to support Location Services . 78
4.4.4.2 Reference point to support Location Services . 78
4.4.4.3 Service Based Interfaces to support Location Services . 78
4.4.5 Application Triggering Services . 78
4.4.6 5G LAN-type Services . 78
4.4.6.1 User plane architecture to support 5G LAN-type service . 78
4.4.6.2 Reference points to support 5G LAN-type service . 79
4.4.7 MSISDN-less MO SMS Service . 79
4.4.8 Architecture to enable Time Sensitive Communication and Time Synchronization . 79
4.4.8.1 General . 79
4.4.8.2 Architecture to support IEEE Time Sensitive Networking . 79
4.4.8.3 Architecture for AF requested support of Time Sensitive Communication and Time
Synchronization . 80
5 High level features. 81
5.1 General . 81
5.2 Network Access Control . 82
5.2.1 General . 82
5.2.2 Network selection . 82
5.2.2a Void . 82
5.2.3 Identification and authentication . 82
5.2.4 Authorisation . 82
5.2.5 Access control and barring . 82
5.2.6 Policy control . 83
5.2.7 Lawful Interception. 83
5.3 Registration and Connection Management . 83
5.3.1 General . 83
5.3.2 Registration Management . 83
5.3.2.1 General . 83
5.3.2.2 5GS Registration Management states. 84
5.3.2.2.1 General . 84
5.3.2.2.2 RM-DEREGISTERED state . 84
5.3.2.2.3 RM-REGISTERED state . 84
5.3.2.2.4 5GS Registration Management State models . 85
5.3.2.3 Registration Area management . 85
5.3.2.4 Support of a UE registered over both 3GPP and Non-3GPP access . 87
5.3.3 Connection Management . 88
5.3.3.1 General . 88
5.3.3.2 5GS Connection Management states . 89
5.3.3.2.1 General . 89
5.3.3.2.2 CM-IDLE state . 89
5.3.3.2.3 CM-CONNECTED state . 89
5.3.3.2.4 5GS Connection Management State models . 90
5.3.3.2.5 CM-CONNECTED with RRC Inactive state . 90
5.3.3.3 NAS signalling connection management . 92
5.3.3.3.1 General . 92
5.3.3.3.2 NAS signalling connection establishment . 93
5.3.3.3.3 NAS signalling connection Release. 93
5.3.3.4 Support of a UE connected over both 3GPP and Non-3GPP access . 93
5.3.4 UE Mobility . 93
5.3.4.1 Mobility Restrictions . 93
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5.3.4.1.1 General . 93
5.3.4.1.2 Management of Service Area Restrictions . 96
5.3.4.2 Mobility Pattern . 98
5.3.4.3 Radio Resource Management functions . 98
5.3.4.3.1 General . 98
5.3.4.3.2 Preferred band(s) per data radio bearer(s) . 99
5.3.4.3.3 Redirection to dedicated frequency band(s) for an S-NSSAI . 99
5.3.4.3.4 Network Slice based cell reselection and Random Access . 100
5.3.4.4 UE mobility event notification . 100
5.3.5 Triggers for network analytics . 101
5.4 3GPP access specific aspects. 101
5.4.1 UE reachability in CM-IDLE. 101
5.4.1.1 General . 101
5.4.1.2 UE reachability allowing mobile terminated data while the UE is CM-IDLE . 102
5.4.1.3 Mobile Initiated Connection Only (MICO) mode . 102
5.4.2 UE reachability in CM-CONNECTED. 103
5.4.3 Paging strategy handling . 104
5.4.3.1 General . 104
5.4.3.2 Paging Policy Differentiation . 104
5.4.3.3 Paging Priority . 105
5.4.4 UE Radio Capability handling . 105
5.4.4.1 UE radio capability information storage in the AMF . 105
5.4.4.1a UE radio capability signalling optimisation (RACS) . 106
5.4.4.2 Void. 110
5.4.4.2a UE Radio Capability Match Request . 110
5.4.4.3 Paging assistance information . 110
5.4.4a UE MM Core Network Capability handling . 111
5.4.4b UE 5GSM Core Network Capability handling . 112
5.4.5 DRX (Discontinuous Reception) framework . 112
5.4.6 Core Network assistance information for RAN optimization . 113
5.4.6.1 General . 113
5.4.6.2 Core Network assisted RAN parameters tuning . 113
5.4.6.3 Core Network assisted RAN paging information . 114
5.4.7 NG-RAN location reporting . 114
5.4.8 Support for identification and restriction of using unlicensed spectrum . 115
5.4.9 Wake Up Signal Assistance . 116
5.4.9.1 General . 116
5.4.9.2 Group Wake Up Signal . 116
5.4.10 Support for identification and restriction of using NR satellite access . 117
5.4.11 Support for integrating NR satellite access into 5GS . 117
5.4.11.1 General . 117
5.4.11.2 Support of RAT types defined in 5GC for satellite access . 117
5.4.11.3 Void. 117
5.4.11.4 Verification of UE location . 117
5.4.11.5 Network selection for NR satellite access . 118
5.4.11.6 Support of Mobility Registration Update . 118
5.4.11.7 Tracking Area handling for NR satellite access . 118
5.4.11.8 Support for mobility Forbidden Area and Service Area Restrictions for NR satellite access . 118
5.4.12 Paging Early Indication with Paging Subgrouping Assistance . 119
5.4.12.1 General . 119
5.4.12.2 Core Network Assistance for PEIPS . 119
5.5 Non-3GPP access specific aspects . 120
5.5.0 General . 120
5.5.1 Registration Management . 120
5.5.2 Connection Management . 120
5.5.3 UE Reachability . 122
5.5.3.1 UE reachability in CM-IDLE . 122
5.5.3.2 UE reachability in CM-CONNECTED . 122
5.6 Session Management . 122
5.6.1 Overview . 122
5.6.2 Interaction between AMF and SMF . 125
5.6.3 Roaming . 127
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5.6.4 Single PDU Session with multiple PDU Session Anchors . 128
5.6.4.1 General . 128
5.6.4.2 Usage of an UL Classifier for a PDU Session . 129
5.6.4.3 Usage of IPv6 multi-homing for a PDU Session. 130
5.6.5 Support for Local Area Data Network . 132
5.6.6 Secondary authentication/authorization by a DN-AAA server during the establishment of a PDU
Session . 134
5.6.7 Application Function influence on traffic routing . 136
5.6.7.1 General . 136
5.6.7.2 Enhancement of UP path management based on the coordination with AFs . 143
5.6.8 Selective activation and deactivation of UP connection of existing PDU Session . 144
5.6.9 Session and Service Continuity . 145
5.6.9.1 General . 145
5.6.9.2 SSC mode . 145
5.6.9.2.1 SSC Mode 1 . 145
5.6.9.2.2 SSC Mode 2 . 146
5.6.9.2.3 SSC Mode 3 . 146
5.6.9.3 SSC mode selection. 146
5.6.10 Specific aspects of different PDU Session types . 147
5.6.10.1 Support of IP PDU Session type . 147
5.6.10.2 Support of Ethernet PDU Session type . 147
5.6.10.3 Support of Unstructured PDU Session type . 149
5.6.10.4 Maximum Transfer Unit size considerations . 150
5.6.11 UE presence in Area of Interest reporting usage by SMF . 151
5.6.12 Use of Network Instance . 152
5.6.13 Always-on PDU session . 152
5.6.14 Support of Framed Routing . 153
5.6.15 Triggers for network analytics . 153
5.7 QoS model . 154
5.7.1 General Overview . 154
5.7.1.1 QoS Flow . 154
5.7.1.2 QoS Profile . 154
5.7.1.2a Alternative QoS Profile . 155
5.7.1.3 Control of QoS Flows . 155
5.7.1.4 QoS Rules . 156
5.7.1.5 QoS Flow mapping . 156
5.7.1.6 DL traffic. 158
5.7.1.7 UL Traffic . 159
5.7.1.8 AMBR/MFBR enforcement and rate limitation . 159
5.7.1.9 Precedence Value . 160
5.7.1.10 UE-Slice-MBR enforcement and rate limitation . 160
5.7.1.11 QoS aspects of home-routed roaming . 160
5.7.2 5G QoS Parameters . 161
5.7.2.1 5QI . 161
5.7.2.2 ARP . 161
5.7.2.3 RQA . 161
5.7.2.4 Notification control . 162
5.7.2.4.1 General . 162
5.7.2.4.1a Notification Control without Alternative QoS Profiles . 162
5.7.2.4.1b Notification control with Alternative QoS Profiles . 162
5.7.2.4.2 Usage of Notification control with Alternative QoS Profiles at handover . 163
5.7.2.4.3 Usage of Notification control with Alternative QoS Profiles during QoS Flow establishment
and modification . 164
5.7.2.5 Flow Bit Rates . 164
5.7.2.6 Aggregate Bit Rates . 165
5.7.2.7 Default values . 165
5.7.2.8 Maximum Packet Loss Rate . 166
5.7.2.9 Wireline access network specific 5G QoS parameters . 166
5.7.3 5G QoS characteristics . 166
5.7.3.1 General . 166
5.7.3.2 Resource Type . 167
5.7.3.3 Priority Level . 167
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5.7.3.4 Packet Delay Budget . 167
5.7.3.5 Packet Error Rate . 168
5.7.3.6 Averaging Window . 168
5.7.3.7 Maximum Data Burst Volume . 169
5.7.4 Standardized 5QI to QoS characteristics mapping . 169
5.7.5 Reflective QoS . 174
5.7.5.1 General . 174
5.7.5.2 UE Derived QoS Rule . 174
5.7.5.3 Reflective QoS Control . 175
5.7.6 Packet Filter Set . 176
5.7.6.1 General . 176
5.7.6.2
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