Content for TR 29.890 Word version: 16.0.0
2 References
3 Definitions and abbreviations
4 Requirements
5 5G Policy Framework
5.1 Reference Model
5.2 Functional Entities
5.3 System Procedures
5.4 Network Function Service Procedures
5.5 Protocols
5.6 AMF Access and Mobility Policy
5.7 Session Management Policy Rules
5.8 UE Policies
5.9 QoS mechanisms
5.10 Discovery and Selection aspects
5.11 Roaming scenarios
5.12 Subscription Data Management
5.13 Interworking with EPC
5.14 IMS Aspects
5.15 Support of MPS services
5.16 Emergency Services
5.17 Mission Critical Services
5.18 Binding Mechanism
5.19 AF influence traffic routing
5.20 Event triggers
2 References p. 10
3 Definitions and abbreviations p. 13
3.1 Definitions p. 13
3.2 Abbreviations p. 13
4 Requirements p. 15
4.1 General Requirements p. 15
4.1.1 Architecture Requirements p. 15
4.1.2 Requirements for protocol selection for service based interfaces p. 15
4.1.3 Additional evaluation criteria for protocol selection for service based interfaces p. 15
4.2 Requirements for the 5G Policy Framework p. 16
4.3 Requirements for interworking between the 5G System and external Data Networks p. 17
4.4 Requirements for Network Capability Exposure of 5G System p. 17
5 5G Policy Framework p. 18
5.1 Reference Model p. 18
5.2 Functional Entities p. 22
5.2.1 Policy Control Function (PCF) p. 22
5.2.2 Session Management Function (SMF) p. 23
5.2.3 Access and Mobility Management Function (AMF) p. 23
5.2.4 Application Function (AF) p. 23
5.2.5 Network Data Analytics Function (NWDAF) p. 23
5.2.6 Network Exposure Function (NEF) p. 24
5.2.7 Unified Data Repository (UDR) p. 24
5.3 System Procedures p. 24
5.3.1 Procedures for Npcf_AMPolicyControl service p. 24
5.3.1.1 Policy request during UE registration p. 24
5.3.1.2 Policy update p. 26
5.3.1.3 Policy context deletion p. 27
5.3.2 Procedures for Npcf_SMPolicyControl service p. 28
5.3.2.1 Request of Session Management (SM) related policies p. 28
5.3.2.2 Update of Session Management (SM) related policies p. 30
5.3.2.2.1 PCF initiated update of SM related policies p. 30
5.3.2.2.2 SMF triggered update of SM related policies p. 30
5.3.2.3 Deletion of the context of SM related policies p. 31
5.3.3 Procedures for Nsmf_EventExposure service p. 32
5.3.3.1 PCF subscription to events p. 32
5.3.3.2 SMF Notification about subscribed events p. 33
5.3.3.3 PCF unsubscription to events p. 34
5.3.4 Procedures over N24 reference point p. 35
5.3.5 Procedure for Npcf_PolicyAuthorization service p. 35
5.3.5.1 Initial provisioning of service information p. 35
5.3.5.2 Modification of service information p. 36
5.3.5.3 AF application session context termination p. 37
5.3.5.3.1 Delete the AF application session context initiated by the AF p. 37
5.3.5.3.2 Delete the AF application session context initiated by the PCF p. 37
5.3.5.4 AF subscription to events p. 38
5.3.5.5 AF unsubscription to events p. 39
5.3.5.6 PCF notification about application session context events p. 40
5.4 Network Function Service Procedures p. 40
5.4.1 General p. 40
5.4.2 Npcf_AMPolicyControl service p. 41
5.4.2.1 General p. 41
5.4.2.2 Operations p. 42
5.4.2.3 Encoding Proposal 1: RESTful HTTP with Policy as PCF resource and custom operation to update policy at AMF p. 43
5.4.2.4 Encoding Proposal 2: RESTful HTTP with Policy as AMF resource p. 47
5.4.2.5 Encoding Proposal 3: RESTful HTTP with Policy as PCF resource and notification to trigger AMF to fetch new policy p. 52
5.4.2.5a Encoding Proposal 4: RESTful HTTP with Policy both as PCF resource and as AMF resource and subscription related information only in PCF resource p. 52
5.4.2.6 Comparison of Encoding Proposals p. 53
5.4.2.7 Conclusions p. 53
5.4.3 Npcf_SMPolicyControl service p. 53
5.4.3.1 General p. 53
5.4.3.2 Operations p. 54
5.4.3.3 Encoding Proposal 1: RESTful HTTP with Policy as PCF resource and custom operation to update policy at SMF p. 55
5.4.3.4 Encoding Proposal 2: RESTful HTTP with Policy as SMF resource p. 59
5.4.3.5 Encoding Proposal 3: RESTful HTTP with Policy as PCF resource and notification to trigger SMF to fetch new policy p. 62
5.4.3.5a Encoding Proposal 4: RESTful HTTP with Policy both as PCF resource and as SMF resource and subscription related information only in PCF resource p. 63
5.4.3.6 Comparison of Proposals p. 63
5.4.3.7 Conclusions p. 63
5.4.4 Npcf_PolicyAuthorization service p. 63
5.4.4.1 General p. 63
5.4.4.2 Operations p. 64
5.4.4.3 Encoding Proposal 1: RESTful HTTP with event subscriptions as sub-resource p. 66
5.4.4.4 Encoding Proposal 2: RESTful HTTP with event subscriptions as a separated sub-resource p. 70
5.4.4.5 Comparison of encoding proposals p. 72
5.4.4.6 Conclusions p. 72
5.4.5 Nsmf_EventExposure p. 72
5.4.6 UDR service p. 77
5.4.6.1 General p. 77
5.4.7 NWDAF services p. 78
5.4.7.1 General p. 78
5.4.7.2 Nnwdaf_Events_Subscription Service p. 78
5.4.7.2.1 General p. 78
5.4.7.2.2 Operations p. 78
5.4.7.3 Nnwdaf_Analytics_Info Service p. 78
5.4.7.3.1 General p. 78
5.4.7.3.2 Operations p. 78
5.5 Protocols p. 79
5.5.1 Protocol Candidates p. 79
5.5.1.1 HTTP2/JSON p. 79
5.5.1.1.1 General p. 79
5.5.1.1.2 HTTP/1.1 p. 79
5.5.1.1.3 HTTP/2 p. 80
5.5.1.1.4 Support of Notifications p. 81
5.5.1.1.4.1 General p. 81
5.5.1.1.4.2 Solution with two client-server pairs p. 81
5.5.1.1.4.3 Solutions with a single client-server pair prior to HTTP/2 p. 82
5.5.1.1.4.4 Solutions with a single client-server pair: HTTP/2 Server Push p. 83
5.5.1.1.4.5 Solution based on Websocket p. 83
5.5.1.1.5 Extensibility Mechanisms p. 84
5.5.1.1.6 HTTP Proxy p. 86
5.5.1.1.7 Protocol Candidate TCP/TLS/HTTP2/JSON p. 86
5.5.1.1.8 Protocol Candidate UDP/QUIC/HTTP2/JSON p. 86
5.5.1.1.9 Evaluation of HTTP aspects p. 86
5.5.1.2 Diameter p. 87
5.5.2 Comparison of RESTful and RPC protocol design p. 88
5.5.2.1 Characteristics of RPCs p. 88
5.5.2.2 Characteristics of REST p. 89
5.5.2.3 Degree of Compliance of the stage 2 requirements with RPC p. 90
5.5.2.4 Degree of Compliance of the stage 2 requirements with REST p. 90
5.5.2.5 Evaluation of RPC p. 92
5.5.2.6 Evaluation of REST p. 92
5.5.2.7 HTTP APIs types p. 93
5.5.2.8 Conclusions p. 93
5.5.3 Data Serialization Format p. 94
5.5.3.1 Introduction p. 94
5.5.3.2 Solution 1 - JSON p. 94
5.5.3.2.1 Description p. 94
5.5.3.2.2 Evaluation p. 94
5.5.3.3 Solution 2 - BSON p. 94
5.5.3.3.1 Description p. 94
5.5.3.3.2 Evaluation p. 95
5.5.3.4 Solution 3 - CBOR p. 95
5.5.3.4.1 Description p. 95
5.5.3.4.2 Evaluation p. 95
5.5.3.5 Conclusion p. 95
5.5.4 Transport protocols p. 96
5.5.5 Interface Definition Language p. 96
5.5.5.1 Introduction p. 96
5.5.5.2 Solution 1 - YANG/RESTCONF p. 97
5.5.5.2.1 Description p. 97
5.5.5.2.2 Evaluation p. 97
5.5.5.3 Solution 2 - OpenAPI Specification (Swagger) p. 97
5.5.5.3.1 Description p. 97
5.5.5.3.2 Evaluation p. 98
5.5.5.4 Solution 3 - Protocol Buffers p. 98
5.5.5.4.1 Description p. 98
5.5.5.4.2 Evaluation p. 98
5.5.5.5 Solution 4 - JSON Content Rules p. 98
5.5.5.5.1 Description p. 98
5.5.5.5.2 Evaluation p. 99
5.5.5.6 Solution 5 - JSON Schema p. 99
5.5.5.6.1 Description p. 99
5.5.5.6.2 Evaluation p. 99
5.5.5.7 Solution 6 - CBOR IDL p. 99
5.5.5.7.1 Description p. 99
5.5.5.7.2 Evaluation p. 99
5.5.5.8 Comparison of IDLs p. 100
5.5.5.9 Conclusion p. 101
5.5.6 Evaluation of candidate protocols for service based interfaces p. 101
5.6 AMF Access and Mobility Policy p. 105
5.7 Session Management Policy Rules p. 106
5.7.1 PCC rule in 5GC p. 106
5.7.1.1 General p. 106
5.7.1.2 PCC rule operations p. 110
5.7.2 5G PDU session related policy information p. 111
5.7.3 Packet Filter Set p. 113
5.7.3.1 General p. 113
5.7.3.2 IP Packet Filter Set p. 113
5.7.3.3 Ethernet Packet Filter Set p. 113
5.8 UE Policies p. 114
5.8.1 General p. 114
5.8.2 UE Access Network discovery and selection policies p. 114
5.8.3 UE Route Selection Policies (URSP) p. 114
5.9 QoS mechanisms p. 115
5.9.1 Overview p. 115
5.9.2 Policy provisioning for authorized QoS per service data flow p. 115
5.9.3 Policy enforcement for authorized QoS per service data flow p. 115
5.9.4 Policy provisioning of authorized QoS per PDU Session p. 116
5.9.5 Policy enforcement for authorized QoS per PDU session p. 116
5.9.6 Reflective QoS p. 116
5.9.6.1 General p. 116
5.9.6.2 Provisioning of authorized Reflective QoS per service data flow p. 116
5.9.6.3 Policy enforcement of authorized Reflective QoS per service data flow p. 116
5.9.6.4 Provisioning and Enforcement of authorized Reflective QoS information per PDU session p. 117
5.9.7 QoS Information p. 117
5.9.7.1 5G QoS Identifier (5QI) p. 117
5.9.7.2 QoS Characteristics p. 117
5.9.7.3 Allocation Retention Priority p. 118
5.9.7.4 Guaranteed Bitrate (DL/UL) p. 119
5.9.7.5 Maximum Bitrate (DL/UL) p. 119
5.9.7.6 Notification Control p. 119
5.9.7.7 PDU Session Aggregate Maximum Bitrate (DL/UL) p. 119
5.9.7.8 UE Aggregate Maximum Bitrate (DL/UL) p. 119
5.9.8 QoS mapping between Rx and N7 p. 119
5.10 Discovery and Selection aspects p. 119
5.10.1 General p. 119
5.10.2 PCF discovery and selection by the AMF p. 120
5.10.3 PCF discovery and selection by the SMF p. 120
5.10.4 Network functionality to assist PCF selection by the AF p. 120
5.11 Roaming scenarios p. 121
5.12 Subscription Data Management p. 122
5.13 Interworking with EPC p. 122
5.14 IMS Aspects p. 124
5.14.1 General p. 124
5.15 Support of MPS services p. 124
5.15.1 General p. 124
5.15.2 Invocation/Revocation of Priority PDU connectivity services p. 125
5.15.3 Invocation/Revocation of IMS Multimedia Priority Services p. 126
5.16 Emergency Services p. 126
5.17 Mission Critical Services p. 126
5.18 Binding Mechanism p. 126
5.18.1 General p. 126
5.18.2 Session Binding p. 127
5.18.3 PCC Rule Authorization p. 127
5.18.4 QoS Flow Binding p. 128
5.19 AF influence traffic routing p. 128
5.19.1 General p. 128
5.19.2 Support of traffic routing request p. 129
5.20 Event triggers p. 131
5.20.1 General p. 131
5.20.2 SMF Event triggers handling p. 131
5.20.3 AMF Event triggers handling p. 133
