Content for TR 23.700-29 Word version: 19.0.0
5 Key Issues
6 Solutions
7 Overall Evaluation
8 Conclusions
A Example network scenarios for regenerative payload generic architecture (e/gNB on LEO satellite)
B Store and Forward Satellite operation
C Example of network scenarios for UE-Sat-UE generic architecture (regenerative payload capabilities on LEO satellite)
$ Change history
5 Key Issues p. 15
5.1 Key Issue #1: Support of Regenerative-based satellite access p. 15
5.1.1 Description p. 15
5.2 Key Issue #2: Support of Store and Forward Satellite operation p. 15
5.2.1 Description p. 15
5.3 Key Issue #3: Support of UE-satellite-UE communication p. 15
5.3.1 Description p. 15
6 Solutions p. 17
6.0 Mapping of Solutions to Key Issues p. 17
6.1 Solution #1: N2/S1 disconnection for satellites leaving an area served by a CN p. 18
6.1.1 Description p. 18
6.1.2 Procedures p. 19
6.1.3 Impacts to Services, Entities and Interfaces p. 20
6.2 Solution #2 for KI#1: Mobility optimization for Regenerative-based satellite access p. 20
6.2.1 Description p. 20
6.2.1.1 TAI/CGI report over N2/S1-AP interface p. 21
6.2.1.2 TNL Connection Suspending over N2/S1-AP interface p. 21
6.2.1.3 Paging p. 22
6.2.2 Procedures p. 22
6.2.2.1 Connecting a RAN node on-board to the CN on the ground p. 22
6.2.2.2 Information Exchanging between RAN node and CN p. 22
6.2.2.2.1 RAN node Configuration for Supported TA list report p. 22
6.2.2.2.2 Reporting Supported TA list to the CN on the ground p. 23
6.2.2.3 TNL management over N2/S1-MME interface p. 23
6.2.2.4 Paging p. 24
6.2.3 Impacts on services, entities and interfaces p. 25
6.3 Solution #3: Support for suspend and resume of NG interface p. 25
6.3.1 Key Issue mapping p. 25
6.3.2 Functional Description p. 25
6.3.4 Impacts on existing services, entities and interfaces p. 26
6.4 Solution #4: Handling awareness of supported TAIs when RAN is onboard p. 26
6.4.1 Description p. 26
6.4.2 Procedures p. 28
6.4.2.1 Procedures of gNB connect to the same AMF via the same gateway p. 28
6.4.2.2 Procedures of gNB connect to a different AMF via a different gateway p. 29
6.4.2.3 Procedures of gNB connect to the same AMF via different gateway p. 29
6.4.3 Impacts to Services, Entities and Interfaces p. 29
6.5 Solution #5: Support of Feeder Link Switchover with TAU for Non-Pooled MMEs p. 30
6.5.1 Description p. 30
6.5.2 Procedures p. 31
6.5.3 Impacts to Services, Entities and Interfaces p. 32
6.6 Solution #6: Load re-balancing for feeder link switchover p. 32
6.6.1 Description p. 32
6.6.2 Procedures p. 32
6.6.2.1 MME procedures p. 32
6.6.2.2 AMF procedures p. 33
6.6.3 Impacts to Services, Entities and Interfaces p. 35
6.7 Solution #7 for Key Issue #1: Feeder link switchover with DL data continuity p. 35
6.7.1 Description p. 35
6.7.2 Procedures p. 35
6.7.3 Impacts to Services, Entities and Interfaces p. 37
6.8 Solution #8 for Key Issue #1: QoS/ Policy handling for Regenerative-based satellite access p. 37
6.8.1 Description p. 37
6.8.2 Procedures p. 38
6.8.2.1 General p. 38
6.8.3 Impacts to Services, Entities and Interfaces p. 39
6.9 Solution #9: Support of Regenerative-based satellite access with deploying RAN-agent and Proxy RAN node or Link Layer Proxy NF p. 39
6.9.1 Description p. 39
6.9.1.1 Support of Regenerative-based satellite access with RAN-agent and Proxy RAN node p. 40
6.9.1.2 Support of Regenerative-based satellite access with Link Layer Proxy p. 41
6.9.2 Procedures p. 42
6.9.2.1 NG Setup, RAN configuration Update and UE registration p. 42
6.9.2.2 Handover with LLP and MME relocation p. 43
6.9.3 Impacts to Services, Entities and Interfaces p. 45
6.10 Solution #10: Regenerative-based satellite access with IWF on S1 or N2/N3 interface p. 45
6.10.1 Key Issue mapping p. 45
6.10.2 Description p. 45
6.10.3 Procedures p. 47
6.10.4 Impacts on services, entities and interfaces p. 47
6.11 Solution #11: MME Split Architecture to support Control plane procedure for S&F p. 47
6.11.1 Key Issue mapping p. 47
6.11.2 Description p. 47
6.11.3 Procedures p. 49
6.11.3.1 Architecture enhancement to support S&F p. 49
6.11.3.2 Attach Procedure in EPC in S&F scenario p. 51
6.11.3.3 MO Data Transport in Control Plane CIoT EPS Optimisation in S&F p. 54
6.11.3.4 Connection Suspend and Resume Procedure p. 57
6.11.3.5 MT Data Transport in Control Plane CIoT EPS Optimisation in S&F p. 58
6.11.4 Impacts on services, entities and interfaces p. 60
6.12 Solution #12: S&F for multiple satellite deployment with anchor MME-ground p. 60
6.12.1 Description p. 60
6.12.2 Procedures p. 61
6.12.2.1 Periodic timer and mobile reachable timer p. 62
6.12.2.2 How UE identifies that it is allowed to attach with network for S/F p. 62
6.12.2.3 GUTI management and MME selection p. 63
6.12.2.4 MME-ground selection by MME-onboard p. 63
6.12.2.5 Authentication procedure/subscription details fetch during any other procedure p. 63
6.12.2.6 Attach with PDN connectivity, multiple satellite p. 63
6.12.3 Impacts on services, entities and interfaces p. 63
6.13 Solution #13: S&F for single satellite deployments with eNB and MME-onboard p. 64
6.13.1 Description p. 64
6.13.2 Procedures p. 65
6.13.2.1 Other changes: p. 66
6.13.2.1.1 Periodic timer and mobile reachable timer p. 66
6.13.2.1.2 How UE identifies that it is allowed to attach with network for S/F p. 66
6.13.2.1.3 UE selecting single satellite in a given area p. 67
6.13.2.1.4 Authentication procedure/subscription details fetch during any other procedure p. 67
6.13.3 Impacts on services, entities and interfaces p. 67
6.14 Solution #14: Initial Registration with prior rejection in satellite network for S&F operation p. 67
6.14.1 Key Issue mapping p. 67
6.14.2 Description p. 67
6.14.3 Procedures p. 69
6.14.4 Impacts on services, entities and interfaces p. 70
6.15 Solution #15: S&F solution for multi-satellite IoT NTN p. 71
6.15.1 Description p. 71
6.15.2 Procedures p. 73
6.15.2.1 Advertising capabilities and activation of S&F Satellite operation p. 74
6.15.2.2 NAS procedures spanning several satellite passes p. 74
6.15.2.3 Data transfer in S&F Satellite operation mode p. 78
6.15.3 Impacts to Services, Entities and Interfaces p. 80
6.16 Solution #16: Enabling S&F operation with C-SGN onboard p. 81
6.16.1 Description p. 81
6.16.2 Procedures p. 82
6.16.2.1 Procedures of NAS Pause/Recovery of S&F Operation p. 82
6.16.2.2 Procedures of Store/Forward of SMS transmission p. 84
6.16.2.3 Procedure of Store/Forward of Data transmission p. 86
6.16.2.3.1 Procedure of MO Data transmission p. 87
6.16.2.3.2 Procedure of MT data transmission p. 88
6.16.2.4 Example of initial attach procedure p. 88
6.16.3 Impacts to Services, Entities and Interfaces p. 91
6.17 Solution #17 for KI#2: Support of Store and Forward Satellite operation for small data transmission p. 92
6.17.1 Description p. 92
6.17.1.1 General p. 92
6.17.1.2 Reference Architecture p. 92
6.17.1.3 UE Authentication for S&F and Parameter Negotiation p. 93
6.17.1.4 Storing and Forwarding MO Data p. 94
6.17.1.5 Storing and Forwarding MT Data p. 94
6.17.2 Procedures p. 95
6.17.2.1 Attach with MO data transmission p. 95
6.17.2.2 Tracking Area Update with MO/MT data transmission p. 96
6.17.2.3 Service Request for MO Data transmission p. 96
6.17.3 Impacts on services, entities and interfaces p. 98
6.18 Solution #18: Attach Procedure with MME and HSS on board the satellite p. 99
6.18.1 Description p. 99
6.18.2 Procedures p. 100
6.18.2.1 Procedures for E-UTRAN Attach in case the onboard HSS holds subscription and credentials for the UE p. 100
6.18.2.2 Procedures for E-UTRAN Attach in case no subscription and credentials for the UE is stored in the onboard HSS p. 102
6.18.2.3 Procedure for MO Data Transport in Control Plane CIoT EPS Optimisation under S&F Satellite Operation p. 104
6.18.2.4 Procedure for MT Data Transport in Control Plane CIoT EPS Optimisation under S&F Satellite Operation p. 105
6.18.3 Impacts to Services, Entities and Interfaces p. 106
6.19 Solution #19: Store and Forward Operation using a UE Proxy and Endpoint Proxy p. 107
6.19.1 Description p. 107
6.19.2 Procedures p. 109
6.19.2.1 Support of MO and MT Transactions p. 109
6.19.2.2 Support of Security p. 112
6.19.2.3 Transition between SSF and Real Time Modes p. 113
6.19.2.4 Support of Discontinuous Satellite Coverage in SSF Mode p. 113
6.19.3 Impacts to Services, Entities and Interfaces p. 114
6.20 Solution #20: Solution on enabling S&F operation and data delivery with only eNB onboard satellite p. 116
6.20.1 Description p. 116
6.20.2 Procedures p. 117
6.20.2.1 Attach Procedure p. 117
6.20.2.2 MT Data delivery in CIoT EPS Optimisation for Store and Forward Operation if feeder link is available p. 119
6.20.2.3 MT Data delivery in CIoT EPS Optimisation for Store and Forward Operation if the feeder link is unavailable p. 121
6.20.2.4 MO Data Delivery in CIoT EPS Optimisation for Store and Forward Operation p. 122
6.20.3 Impacts to Services, Entities and Interfaces p. 123
6.21 Solution #21: Support of store and forward satellite operation in EPS p. 124
6.21.1 Description p. 124
6.21.2 Procedures p. 125
6.21.3 Impacts to Services, Entities and Interfaces p. 129
6.22 Solution #22 for Key Issue #2: Support of Store and Forward Satellite operation for SMS and Data Transmission p. 130
6.22.1 Introduction p. 130
6.22.2 Description p. 130
6.22.3 Procedures p. 132
6.22.3.1 Provision of available communication information p. 132
6.22.3.2 MT SMS Delivery procedure related to HSS p. 132
6.22.3.3 MT SMS Delivery procedure related to MME p. 134
6.22.3.3A MO SMS Delivery procedure p. 136
6.22.3.4 MT/MO data transmission p. 137
6.22.3.5 Support for multiple satellites serving a UE p. 139
6.22.4 Impacts on services, entities and interfaces p. 140
6.23 Solution #23: Support for SMS in satellite network for S&F operation p. 141
6.23.1 Key Issue mapping p. 141
6.23.2 Description p. 141
6.23.3 Procedures p. 143
6.23.3.1 Mobile Terminated SMS p. 143
6.23.3.2 Mobile Originated SMS p. 144
6.23.4 Impacts on services, entities and interfaces p. 144
6.24 Solution #24: Enhancement of registration and PDU session establishment to support on-board S&F p. 144
6.24.1 Description p. 144
6.24.2 Procedures p. 146
6.24.2.1 Option 1: Procedures of User plane enabled S&F p. 146
6.24.2.2 Option 2: Procedures of 5GC enabled S&F p. 148
6.24.3 Impacts to Services, Entities and Interfaces p. 148
6.25 Solution #25: UE reachability estimation p. 149
6.25.1 Key Issue mapping p. 149
6.25.2 Description p. 149
6.25.4 Impacts on services, entities and interfaces p. 151
6.26 Solution #26: Provision of Store and Forward Satellite Specific Parameters p. 151
6.26.1 Description p. 151
6.26.2 Procedures p. 152
6.26.3 Impacts on services, entities and interfaces p. 152
6.27 Solution #27: Performance optimization for the transport of MT/MO S&F traffic p. 153
6.27.1 Description p. 153
6.27.1.1 S&F Deployment Architecture p. 153
6.27.1.2 Performance impact from the accumulation of stored MT/MO traffic p. 154
6.27.1.3 Performance optimization to forward accumulated MT/MO traffic p. 154
6.27.2 Procedures p. 156
6.27.2.1 General procedure for performance optimization p. 157
6.27.2.2 Enhanced procedure for S&F UE Registration p. 157
6.27.2.3 Enhanced procedure for S&F Service Request p. 158
6.27.3 Impacts on services, entities and interfaces p. 158
6.28 Solution #28: UE-Satellite-UE Communication via UPFs onboard the satellites p. 159
6.28.1 Description p. 159
6.28.1.1 Reference Architecture p. 159
6.28.1.2 Identifying UEs applicable for UE-Satellite-UE Communication p. 160
6.28.1.3 UL CL/BP/local PSA UPF selection for UE-Satellite-UE Communication p. 160
6.28.2 Procedures p. 161
6.28.2.1 UE-satellite-UE communication procedure in IMS system p. 161
6.28.2.2 Ground common SMF for UE-SAT-UE communication p. 163
6.28.2.3 Ground common I/V-SMF for UE-SAT-UE communication p. 164
6.28.2.4 Handover procedure when serving satellite changes p. 165
6.28.3 Impacts to Services, Entities and Interfaces p. 166
6.29 Solution #29: SMF activated UE-satellite-UE communication for IMS service p. 167
6.29.1 Description p. 167
6.29.2 Procedures p. 167
6.29.3 Impacts to Services, Entities and Interfaces p. 169
6.30 Solution #30: Solution to determine UE-SATs-UE eligibility and enable communication setup p. 169
6.30.1 Description p. 169
6.30.2 Procedures p. 170
6.30.3 Impacts on existing nodes and functionalities p. 171
6.31 Solution #31: UE-satellite-UE communication for IMS voice and video (UPF onboard) p. 172
6.31.1 Description p. 172
6.31.2 Procedures p. 173
6.31.3 Impacts on services, entities and interfaces p. 173
6.32 Solution #32 for Key Issue #3: Support of UE-satellite-UE communication for IMS services with UPF/AGW inserted on satellites p. 174
6.32.1 Description p. 174
6.32.2 Procedures p. 176
6.32.2.1 Provision of access network information in 5GC p. 176
6.32.2.2 Provision of access network information to IMS p. 176
6.32.2.3 IMS procedures to determine to perform the UE-satellite-UE communication p. 177
6.32.2.4 IMS influence on traffic routing p. 179
6.32.3 Impacts to Services, Entities and Interfaces p. 179
6.33 Solution #33: Solution for UE-satellite-UE communication with IMS media entity onboard p. 180
6.33.1 Description p. 180
6.33.2 Procedures p. 182
6.33.2.1 UE-Satellite-UE Communication Signalling p. 182
6.33.2.2 Minimize service interruption if the Serving Satellite changes p. 183
6.33.3 Impacts on services, entities and interfaces p. 184
6.34 Solution #34: Enhancement on AMF discovery for Regenerative-based satellite p. 185
6.34.1 Description p. 185
6.34.2 Procedures p. 185
6.34.3 Impacts on services, entities and interfaces p. 186
6.35 Solution #35: N2/S1 procedures to handle feeder link switch p. 187
6.35.1 Description p. 187
6.35.2 Procedures p. 188
6.35.3 Impacts to Services, Entities and Interfaces p. 188
6.36 Solution #36: User plane path failure management due to satellites leaving an area served by a CN p. 189
6.36.1 Description p. 189
6.36.2 Procedures p. 189
6.36.3 Impacts to Services, Entities and Interfaces p. 189
6.37 Solution #37: AMF Split Architecture to support Control plane procedure for S&F p. 190
6.37.1 Key Issue mapping p. 190
6.37.2 Description p. 190
6.37.3 Procedures p. 191
6.37.3.1 5GS Architecture enhancement to support S&F p. 191
6.37.3.2 Registration Procedure in 5GS in S&F scenario p. 192
6.37.3.3 UE Reachability Estimation (Satellite Location/Coverage Information) p. 196
6.37.4 Impacts on services, entities and interfaces p. 197
6.38 Solution #38: Exposure of Registration in S&F Mode p. 198
6.38.1 Description p. 198
6.38.2 Procedures p. 199
6.38.3 Impacts on services, entities and interfaces p. 199
6.39 Solution #39: Session creation and parameters provisioning for S&F p. 199
6.39.1 Key Issue mapping p. 199
6.39.2 Description p. 199
6.39.3 MME, SGW and PGW onboard p. 200
6.39.4 Impacts on services, entities and interfaces p. 201
6.40 Solution #40: User plane offload from P-CSCF/IMS-AGW located on the ground p. 201
6.40.1 Description p. 201
6.40.1.1 General p. 201
6.40.1.2 Architecture assumption p. 202
6.40.2 Procedures p. 202
6.40.3 Impacts on existing services, entities and interfaces p. 208
6.41 Solution #41: Support of UE-satellite-UE communication for IMS services with UPF/AGW on board p. 208
6.41.1 Description p. 208
6.41.2 Procedures p. 210
6.41.3 Impacts to Services, Entities and Interfaces p. 213
6.42 Solution #42: UE-satellite-UE communication in the context of LEO satellite constellations with ISL p. 214
6.42.1 Description p. 214
6.42.2 Procedures p. 215
6.42.2.1 Association of Relay entity representative of satellite constellations p. 215
6.42.2.2 Registration Procedure p. 217
6.42.2.3 IMS PDU Session Establishment Procedure p. 218
6.42.2.4 IMS registration and voice call setup procedure p. 219
6.42.3 Impacts on services, entities, and interfaces p. 222
6.43 Solution #43: UE-Sat-UE communication using resource allocation on-board satellite p. 222
6.43.1 Key Issue mapping p. 222
6.43.2 Description p. 223
6.43.3 Procedures p. 225
6.43.3.1 Overview p. 225
6.43.3.2 PCC and SMF Procedures for IMS Session Establishment at terminating P-CSCF and PCF p. 225
6.43.3.3 PCC and SMF Procedures for IMS Session Establishment at Originating P-CSCF and PCF p. 228
6.43.3.4 Change of Satellite in UE-Sat-UE scenario (mobility) p. 231
6.43.3.4a Roaming case in UE-Sat-UE scenario p. 234
6.43.3.5 Support for jurisdictions where LI can apply p. 234
6.43.4 Impacts on services, entities and interfaces p. 240
6.44 Solution #44: eNB buffered signalling and CP data transfer with eNB monitoring list p. 241
6.44.1 Description p. 241
6.44.1a Architecture p. 242
6.44.2 Procedures p. 242
6.44.2.1 Attach Procedure p. 242
6.44.2.2 MT control plane data transfer in S&F operation mode p. 245
6.44.2.3 MO control plane data transfer in S&F operation mode p. 246
6.44.2.4 Negotiation of S&F Monitoring List p. 247
6.44.3 Impacts on services, entities and interfaces p. 247
6.45 Solution#45: Support SMS in S&F satellite operation p. 248
6.45.0 Introduction p. 248
6.45.1 Description p. 248
6.45.2 Procedures p. 249
6.45.3 Impacts on Existing Nodes and Functionality p. 251
7 Overall Evaluation p. 252
7.1 Solution grouping for Key Issue #1: Support of Regenerative-based satellite access p. 252
7.2 Key Issue #2 Principles for evaluation p. 253
8 Conclusions p. 253
8.1 Conclusion for KI#1: Support of Regenerative-based satellite access p. 253
8.2 Conclusion for KI #2: Support of Store and Forward Satellite operation p. 254
8.3 Conclusion for KI#3: Support of UE-Sat-UE communication p. 256
8.3.1 General p. 256
8.3.2 Ground Fallback Option p. 256
A Example network scenarios for regenerative payload generic architecture (e/gNB on LEO satellite) p. 258
B Store and Forward Satellite operation p. 262
C Example of network scenarios for UE-Sat-UE generic architecture (regenerative payload capabilities on LEO satellite) p. 264
$ Change history p. 266
