TR 32.899
Study on Charging aspects
of 5G System Architecture Phase 1

3GPP‑Page

V15.1.0 (Wzip) 2018/03 104 p.

Rapporteur:: Miss CHEN, SHAN
Huawei Tech.(UK) Co.. Ltd

full Table of Contents for TR 32.899 Word version: 15.1.0

Scope p. 10

References p. 10

Definitions, symbols and abbreviations p. 11

3.1	Definitions p. 11
3.2	Symbols p. 11
3.3	Abbreviations p. 11

High-level description and potential requirements p. 12

4.1

Potential high-level charging requirements p. 12

4.2

Reference 5G system architectures p. 12

4.2.1

Non-roaming 5G system architecture p. 12

4.2.2

Roaming 5G system architecture p. 14

4.2.2.1	Roaming 5G system architecture - LBO scenario p. 14
4.2.2.2	Roaming 5G system architecture - Home routed scenario p. 15

4.3

Conventions p. 16

Topics p. 17

5.1

Session management and service continuity p. 17

5.1.1

Description and assumptions p. 17

5.1.2

Potential requirements p. 17

5.1.3

Key issues p. 17

5.1.3.1	Key issue #1.1: PDU session charging p. 17
5.1.3.2	Key issue #1.2: PDU session charging - SSC Mode 1 p. 17
5.1.3.3	Key issue #1.3: PDU session charging - SSC Mode 2 p. 18
5.1.3.4	Key issue #1.4: PDU session charging - SSC Mode 3 - parallel traffic p. 18

5.1.4

Solutions p. 18

5.1.4.1

Solution#1.1: PDU session charging from SMF p. 18

5.1.4.1.1	Architecture description p. 18
5.1.4.1.2	Procedure description p. 19
5.1.4.1.3	Solution evaluation p. 21

5.1.4.2

Solution#1.2: PDU session charging SSC Mode 1 from SMF p. 21

5.1.4.2.1	Architecture description p. 21
5.1.4.2.2	Procedure description p. 22
5.1.4.2.3	Solution evaluation p. 23

5.1.4.3

Solution#1.3: PDU session Charging SSC Mode 2 from SMF - CH session update p. 23

5.1.4.3.1	Architecture description p. 23
5.1.4.3.2	Procedure description p. 24

5.1.4.4

Solution#1.4: PDU session Charging SSC Mode 2 from SMF - new CH session p. 25

5.1.4.4.1	Architecture description p. 25
5.1.4.4.2	Procedure description p. 25

5.1.4.5

Solution#1.5: PDU session Charging SSC Mode 3 from SMF - CH session update p. 26

5.1.4.5.1	Architecture description p. 26
5.1.4.5.2	Procedure description p. 26

5.1.4.6

Solution#1.6: PDU session Charging SSC Mode 3 from SMF - New CH session p. 28

5.1.4.6.1

Architecture description p. 28

5.1.4.6.2

Procedure description p. 28

5.1.4.6.2.1	Scenario - no SMF reallocation p. 28
5.1.4.6.2.2	Scenario with SMF reallocation p. 29

5.1.4.7

Solution#1.7: PDU session Charging SSC Mode 3 Multi Homed from SMF - CH session update p. 30

5.1.4.7.1	Architecture description p. 30
5.1.4.7.2	Procedure description p. 30

5.1.4.8

Solution#1.8: PDU session Charging SSC Mode 3 Multi Homed from SMF - New CH session p. 32

5.1.4.8.1	Architecture description p. 32
5.1.4.8.2	Procedure description p. 32

5.1.5

Evaluation and conclusion p. 32

5.1.5.1

Architecture p. 32

5.1.5.2

Evaluation p. 33

5.1.5.2.1	Solutions evaluation for Key issue #1.3 p. 33
5.1.5.2.2	Solutions evaluation for Key issue #1.4 p. 33

5.1.5.3

Conclusion p. 34

5.2

QoS p. 34

5.2.1

Description and assumptions p. 34

5.2.2

Potential requirements p. 34

5.2.3

Key issues p. 34

5.2.3.1

Key issue#2.1 : QoS flow based charging p. 34

5.2.4

Solutions p. 35

5.2.4.1

Solution#2.1 QoS flow based charging - Reporting level per combination of the rating group and QFI p. 35

5.2.4.1.1	Architecture description p. 35
5.2.4.1.2	Procedure description p. 35

5.2.4.2

Solution#2.2 QoS flow based charging - Reporting level per combination of the rating group and QoS flow identifier and Service ID p. 36

5.2.4.2.1	Architecture description p. 36
5.2.4.2.2	Procedure description p. 36

5.2.4.3

Solution#2.3 QoS flow based charging - Reporting level per combination of the rating group and QoS flow identifier and Sponsor Id/Application service provider identity p. 36

5.2.4.3.1	Architecture description p. 36
5.2.4.3.2	Procedure description p. 36

5.2.5

Overall evaluation and conclusion p. 37

5.2.5.1	Solution evaluation p. 37
5.2.5.2	Conclusions p. 37

5.3

Interaction between SMF and UPF p. 37

5.3.1

Description and assumptions p. 37

5.3.1.0

General p. 37

5.3.1.1

Traffic monitoring, diversion, and blocking p. 38

5.3.1.1.1

Description and assumptions p. 38

5.3.1.2

Type of units for rating p. 38

5.3.1.2.1

Description and assumptions p. 38

5.3.2

Potential requirements p. 38

5.3.3

Key issues p. 39

5.3.3.1	Key issue #3.1: Traffic monitoring p. 39
5.3.3.2	Key issue #3.2: Blocking and diversion p. 39
5.3.3.3	Key issue #3.3: Support of duration p. 39
5.3.3.4	Key issue #3.4: Triggers and reporting in the separate SMF and UPF p. 39
5.3.3.5	Key issue #3.5: Quota management in the separate SMF and UPF p. 39
5.3.3.6	Key issue #3.6: PDU session Charging - Branching Point or UL Classifier p. 39
5.3.3.7	Key issue #3.7: Bytes counted as continuous and discrete time p. 40

5.3.4

Solutions p. 40

5.3.4.1

Solution#3.1: The reporting and quota management in the separation SMF and UPF p. 40

5.3.4.1.1	Architecture description p. 40
5.3.4.1.2	Offline Charging p. 41
5.3.4.1.3	Online charging p. 42
5.3.4.1.4	Solution evaluation p. 43

5.3.4.2

Solution#3.2: PDU session charging - counts in BP/UL CL UPF only p. 43

5.3.4.2.1	Architecture description p. 43
5.3.4.2.2	Procedure description - Addition of additional PDU Session Anchor and Branching Point or UL CL p. 43
5.3.4.2.3	Procedure description - Removal of additional PDU Session Anchor and Branching Point or UL CL p. 45
5.3.4.2.4	Procedure description - Additional PDU Session anchor relocation for UL CL p. 46
5.3.4.2.5	Procedure description - Relocation of UL CL for a PDU Session p. 47

5.3.4.3

Solution#3.3: PDU session charging - counts in two UPFs - single CH session p. 49

5.3.4.3.1	Architecture description p. 49
5.3.4.3.2	Procedure description - Addition of additional PDU Session Anchor and Branching Point or UL CL p. 49
5.3.4.3.3	Procedure description - Removal of additional PDU Session Anchor and Branching Point or UL CL p. 51
5.3.4.3.4	Procedure description - Additional PDU Session anchor relocation for UL CL p. 51
5.3.4.3.5	Procedure description - Relocation of UL CL for a PDU Session p. 51

5.3.4.4

Solution#3.4: The reporting and quota management SSC mode 2 - CH session update p. 51

5.3.4.4.1

Architecture description p. 51

5.3.4.4.2

Procedure description p. 51

5.3.4.4.2.0	General Description p. 51
5.3.4.4.2.1	Solution 3.4.1: The Charging system is aware of the UPF change p. 52
5.3.4.4.2.2	Solution 3.4.2: The Charging system is not aware of the UPF change p. 53

5.3.4.5

Solution#3.5: The reporting and quota management - in multiple UPFs (parallel traffic) p. 53

5.3.4.5.1

Architecture description p. 53

5.3.4.5.2

Procedure description p. 54

5.3.4.5.2.0	General Description p. 54
5.3.4.5.2.1	Solution 3.5.1 Charging system granted quota shared by UPFs p. 54
5.3.4.5.2.2	Solution 3.5.2 Charging System grants the quota for each UPF p. 57

5.3.4.6

Solution#3.6: Bytes counted as continuous time p. 58

5.3.4.6.1	Architecture description p. 58
5.3.4.6.2	Procedure description p. 58
5.3.4.6.3	Solution evaluation. p. 58

5.3.4.7

Void p. …

5.3.4.8

Solution#3.8: Charging at SMF and usage monitoring over N4 p. 58

5.3.4.8.1	Architecture description p. 58
5.3.4.8.2	Procedure description p. 58
5.3.4.8.3	Solution evaluation. p. 60

5.3.4.9

Solution#3.9: PDU session charging - counts in UPFs - single CH session p. 60

5.3.4.9.1	Architecture description p. 60
5.3.4.9.2	Procedure description- Addition of additional PDU Session Anchor and Branching Point or UL CL p. 60
5.3.4.9.3	Procedure description - Removal of additional PDU Session Anchor and Branching Point or UL CL p. 61
5.3.4.9.4	Procedure description - Additional PDU Session anchor relocation for UL CL p. 63
5.3.4.9.5	Procedure description - Relocation of UL CL for a PDU Session p. 64

5.3.4.10

Solution#3.10: The reporting and quota management SSC mode 2 - New CH session p. 65

5.3.4.10.1	Architecture description p. 65
5.3.4.10.2	Procedure description p. 65

5.3.5

Overall evaluation and conclusion p. 66

5.3.5.1

Evaluation p. 66

5.3.5.1.1	Solutions evaluation for Key issue #3.1 and #3.2 p. 66
5.3.5.1.2	Solutions evaluation for Key issue #3.3 p. 66
5.3.5.1.3	Solutions evaluation for Key issue #3.4 p. 66
5.3.5.1.4	Solutions evaluation for Key issue #3.5 p. 66
5.3.5.1.5	Solutions evaluation for Key issue #3.6 p. 67

5.3.5.2

Conclusion p. 67

5.4

Network Slicing p. 67

5.4.1

Description and assumptions p. 67

5.4.2

Potential requirements p. 68

5.4.3

Key issues p. 68

5.4.3.1	Key issue #4.1: Charging for UE served by one or more Network Slice instances p. 68
5.4.3.2	Key issue #4.2: Charging for the CSP who utilizes a specific network slice instance p. 68

5.4.4

Solutions p. 69

5.4.4.1

Solution#4.1: Charging for UE - different architecture options p. 69

5.4.4.1.1

Offline charging p. 69

5.4.4.1.1.1	Option #1: The offline charging system with CDF and CGF in two separate physical elements p. 69
5.4.4.1.1.2	Option #2: The offline charging system with CDF integrated in the NE, CGF in a separate physical element p. 69
5.4.4.1.1.3	Option #3: The offline charging system with CDF and CGF integrated in the NE p. 70

5.4.4.1.2

Online charging p. 70

5.4.4.1.2.0	General Description p. 70
5.4.4.1.2.1	Option #1: The online charging system is shared by all the Network Slice instances per PLMN p. 71
5.4.4.1.2.2	Option #2: online charging by instantiating a slice-specific OCF/RF/CGF for each Network Slice instance p. 71

5.4.4.1.3

Solution evaluation p. 72

5.4.4.2

Solution#4.2: Charging for creating and modifying a Network Slice by a CSP p. 72

5.4.4.2.1	Offline charging p. 72
5.4.4.2.2	Online charging p. 73

5.4.4.3

Solution#4.3: Charging procedure for UE served by multiple network slice instances p. 74

5.4.4.3.1	Procedure description p. 74
5.4.4.3.2	Solution evaluation p. 74

5.4.5

Conclusions p. 75

5.5

Network Capability Exposure p. 75

5.5.1

Description and assumptions p. 75

5.5.2

Potential requirements p. 75

5.5.3

Key issues p. 76

5.5.3.1	Key issue #5.1: Charging for network capability exposure p. 76
5.5.3.2	Key issue #5.2: Exposure of Charging System as network capability p. 76

5.5.4

Solutions p. 76

5.5.4.1

Solution#5.1: Charging for network capability external exposure - Ro/Rf p. 76

5.5.4.1.1	Architecture description p. 76
5.5.4.1.2	Procedure description p. 76

5.5.4.2

Solution#5.2: Exposure of Charging System as network capability p. 77

5.5.4.2.1

Architecture description p. 77

5.5.4.3

Solution#5.3: Charging for internal network capability exposure p. 77

5.5.4.3.1	Architecture description p. 77
5.5.4.3.2	Procedure description p. 78

5.5.4.4

Solution#5.4: Charging for Event Exposure with bulk subscription p. 78

5.5.4.4.1	Architecture description p. 78
5.5.4.4.2	Procedure description p. 78

5.5.4.5

Solution#5.5: Charging for network capability external exposure - Nch p. 79

5.5.4.5.1	Architecture description p. 79
5.5.4.5.2	Procedure description p. 79

5.5.5

Evaluation and conclusion p. 79

5.5.5.1	Evaluation p. 79
5.5.5.2	Conclusion p. 79

5.6

Roaming p. 80

5.6.1

Description and assumption p. 80

5.6.1.0	General p. 80
5.6.1.1	PDU session - roaming LBO p. 80
5.6.1.2	PDU session - roaming Home Routed p. 80

5.6.2

Potential requirements p. 80

5.6.3

Key issues p. 80

5.6.3.1

Key issue #6.1: Online charging from HPLMN p. 80

5.6.4

Solutions p. 81

5.6.4.1

Solution #6.1: PDU session charging from SMF in roaming LBO - CH in VPLMN p. 81

5.6.4.1.1	Architecture description p. 81
5.6.4.1.2	Procedures description p. 81
5.6.4.1.3	Charging mode and objective p. 81
5.6.4.1.4	Charging architecture - additional considerations p. 82
5.6.4.1.5	Solution evaluation p. 82

5.6.4.2

Solution #6.2: PDU session charging from SMF in roaming LBO - CH in HPLMN p. 82

5.6.4.2.1	Architecture description p. 82
5.6.4.2.2	Procedures description p. 82
5.6.4.2.3	Charging mode and objective p. 83
5.6.4.2.4	Charging architecture - additional considerations p. 83
5.6.4.2.5	Solution evaluation p. 83

5.6.4.3

Solution #6.3: PDU session charging from SMFs in Home Routed p. 84

5.6.4.3.1

Architecture description p. 84

5.6.4.3.2

Procedures description p. 84

5.6.4.3.3

Charging mode and objective p. 86

5.6.4.3.4

Charging architecture - additional considerations p. 86

5.6.4.3.4.1	Description p. 86
5.6.4.3.4.2	Solution #6.3.1: solutions #9.1 (Combined online and offline charging) for VPLMN p. 86
5.6.4.3.4.3	Solution #6.3.2: solutions #9.2 (Partial combined online and offline charging) for VPLMN p. 86
5.6.4.3.4.4	Solution #6.3.3: solutions #9.3 (Online charging with unlimited quota for offline) for VPLMN p. 87
5.6.4.3.4.5	Solution #6.3.4: Rf solution for VPLMN p. 87

5.6.4.3.5

Solution evaluation p. 87

5.6.4.4

Solution #6.4: PDU session charging from SMF in roaming LBO - CH in HPLMN and VPLMN p. 88

5.6.4.4.1	Architecture description p. 88
5.6.4.4.2	Procedures description p. 88
5.6.4.4.3	Charging mode and objective p. 88
5.6.4.4.4	Additional considerations p. 89
5.6.4.4.5	Solution evaluation p. 89

5.6.5

Overall evaluation and conclusion p. 89

5.6.5.1	Overall evaluation p. 89
5.6.5.2	Conclusion p. 89

5.7

Service-based architecture p. 90

5.7.1

Description and assumptions p. 90

5.7.2

Potential requirements p. 90

5.7.3

Key issues p. 90

5.7.3.1

Key issue #7.1: The service interface for Charging Domain p. 90

5.7.4

Solutions p. 90

5.7.4.1

Solution#7.1: Service interface for SMF and Charging Domain p. 90

5.7.4.1.1	Architecture description p. 90
5.7.4.1.2	Service identification p. 90

5.7.4.2

Solution#7.2: Reference point representation for SMF and Charging Domain p. 91

5.7.4.3

Solution#7.3: Service interface for SMF and Charging Domain p. 92

5.7.4.4

Solution evaluation p. 92

5.7.5

Conclusions p. 92

5.8

Interworking between 5G System and existing systems p. 93

5.8.1

Description and assumptions p. 93

5.8.2

Potential requirements p. 93

5.8.3

Key issues p. 93

5.8.3.1	Key issue #8.1: <Charging for 5GS to EPS handover> p. 93
5.8.3.2	Key issue #8.2: <Charging for EPS to 5GS handover> p. 93

5.8.4

Solutions p. 94

5.8.4.1	Solution#8.1: 5GS to EPS handover using N26 interface p. 94
5.8.4.2	Solution#8.2: EPS to 5G handover using N26 interface p. 95

5.8.5

Evaluation and conclusion p. 97

5.8.5.1	Solution Evaluation p. 97
5.8.5.2	Conclusions p. 97

5.9

Online and offline charging evaluation p. 97

5.9.1

Description and assumption p. 97

5.9.1.1	Existing functionalities p. 97
5.9.1.2	Considerations for 5G p. 98

5.9.2

Potential requirements p. 98

5.9.3

Key issues p. 98

5.9.3.1	Key issue #9.1: CDRs generation for online p. 98
5.9.3.2	Key issue #9.2: Offline charging only p. 98

5.9.4

Solutions p. 99

5.9.4.1

Solution #9.1: Combined online and offline charging p. 99

5.9.4.1.1	Architecture description p. 99
5.9.4.1.2	Procedures description p. 99
5.9.4.1.3	Solution evaluation. p. 99

5.9.4.2

Solution #9.2: Partial combined online and offline charging p. 100

5.9.4.2.1	Architecture description p. 100
5.9.4.2.2	Procedures description p. 100
5.9.4.2.3	Solution evaluation. p. 100

5.9.4.3

Solution #9.3: Online charging with unlimited quota for offline p. 101

5.9.4.3.1	Architecture description p. 101
5.9.4.3.2	Procedures description p. 101
5.9.4.3.3	Solution evaluation. p. 101

5.9.5

Overall evaluation and conclusion. p. 101

5.9.5.1	Overall evaluation p. 101
5.9.5.2	Conclusion p. 102

5.10

Connection, registration and mobility management p. 102

5.10.1

Description and assumptions p. 102

5.10.2

Potential requirements p. 102

5.10.3

Key issues p. 102

5.10.4

Solutions p. 102

5.10.4.1

Solution#10.1: No charging for registration p. 102

5.10.4.1.1	Architecture description p. 102
5.10.4.1.2	Procedure description p. 102
5.10.4.1.3	Solution evaluation. p. 103

5.10.5

Conclusion p. 103

Conclusions and recommendations p. 103

6.1	Conclusions p. 103
6.2	Recommendations p. 103

Change History p. 104

TR 32.899 Study on Charging aspects of 5G System Architecture Phase 1

full Table of Contents for TR 32.899 Word version: 15.1.0

TR 32.899
Study on Charging aspects
of 5G System Architecture Phase 1