TR 23.873
Feasibility study for Transport and Control separation in the PS CN domain
V4.0.0 (Wzip)
2001/04 91 p.
- Rapporteur:
- Mr. Ibanez, Juan-Antonio
Ericsson LM
full Table of Contents for TR 23.873 Word version: 4.0.0
1 Scope p. 6
The scope of this Technical Report (TR) is to capture the results of a feasibility study on how to introduce a clear separation of transport and control functions in the PS CN domain, with minimum impacts on the reference logical architecture for R'00.
With this separation in view, functional elements of the PS CN domain that provide both significant control and transport functions may be decomposed into two separate functional entities: one entity taking care of the control functionality and an other entity handling the payload transport. An exact distribution of the functions currently supported by a single functional entity between new functional entities and other network entities will be defined as the result of this feasibility study, if necessary.
A standard control protocol should be used between the control and transport entities, if applicable, e.g. H.248. The required functionality, e.g. extensions to H.248 or any other protocol which may be chosen for this task, would have to be defined and standardised within 3GPP. This TR will identify and define these extensions, and extensions to other interfaces if applicable.
More generally, the aim of this TR is to identify and strive to solve all issues introduced by such evolution of the PS CN domain. At the end of the feasibility study, the remaining open issues will be reported and their importance will be assessed. An analysis of the benefits and drawbacks of separating the control and transport functions in the PS CN domain will also be performed.
2 References p. 7
3 Symbols and Abbreviations p. 7
3.1 Symbols p. 7
3.2 Abbreviations p. 7
4 Introduction p. 7
5 Reference Logical Architecture p. 8
6 Alternative 1: SGSN Server - PS Media Gateway Approach p. 8
6.1 Introduction p. 8
6.2 Logical Architecture p. 9
6.2.1 Functional Nodes p. 10
6.2.2 Interfaces p. 11
6.2.2.1 SGSN server - PS-MGW (Mp) (Iu Mode Only) p. 11
6.2.2.2 UTRAN - SGSN server (Iu) (Iu Mode Only) p. 11
6.2.2.3 UTRAN - PS-MGW (Iu) (Iu Mode Only) p. 11
6.2.2.4 BSS - 2G-SGSN (Gb) (Gb Mode Only) p. 11
6.2.2.5 2G-SGSN/SGSN server - GGSN (Gn, Gp) p. 11
6.2.2.6 PS-MGW - GGSN (Gn) (Iu Mode Only) p. 11
6.2.2.7 Gn interface for inter SGSN procedures p. 11
6.2.3 User plane p. 11
6.3 H.248 option over Mp p. 12
6.3.1 Mobility Management (H.248 option) p. 12
6.3.1.1 Detach Procedures p. 12
6.3.1.2 Routing Area Update Procedure p. 13
6.3.1.3 Serving SRNS Relocation Procedure p. 16
6.3.1.4 UMTS to GSM Intra SGSN Change p. 19
6.3.1.5 GSM to UMTS Intra SGSN Change p. 21
6.3.1.6 UMTS to GSM Inter SGSN Change p. 23
6.3.1.7 GSM to UMTS Inter SGSN Change p. 25
6.3.2 Session Management (H.248 option) p. 27
6.3.2.1 PDP Context Activation Procedure p. 27
6.3.2.2 Secondary PDP Context Activation Procedure p. 28
6.3.2.3 Network-Requested PDP Context Activation Procedure p. 29
6.3.2.4 PDP Context Modification Procedures p. 29
6.3.2.5 PDP Context Deactivation Procedure p. 31
6.3.2.6 Iu Release Procedure p. 32
6.3.2.7 Service Request Initiated by MS Procedure p. 33
6.3.2.8 Service Request Initiated by Network Procedure p. 34
6.3.3 Charging (H.248 option) p. 35
6.3.3.1 Handling of S-CDR p. 35
6.3.3.2 Handling of other types of CDRs in the SGSN server p. 36
6.3.3.3 Handling of prepaid on-line p. 36
6.3.3.4 Handling of hot-billing p. 36
6.3.3.5 General charging issues on the Mp interface p. 37
6.3.4 CAMEL Considerations (H.248 option) p. 37
6.3.4.1 Handling of Volume Based CAMEL Charging p. 37
6.3.4.2 Handling of Time Based CAMEL Charging p. 38
6.3.5 Lawful Interception (H.248 option) p. 39
6.3.5.1 Lawful Interception of Content of Communications p. 39
6.3.5.2 Lawful Interception of Intercept Related Information p. 40
6.3.6 QoS Considerations (H.248 option) p. 40
6.3.7 Abnormal Cases (H.248 option) p. 40
6.4 GTP-C option over Mp p. 40
6.4.1 Mobility Management (GTP-C option) p. 41
6.4.2 Session Management (GTP-C option) p. 44
6.4.2.1 PDP Context Activation Procedure p. 44
6.4.2.2 PDP Context Modification Procedures p. 45
6.4.2.3 PDP Context Deactivation Procedure p. 45
6.4.2.4 RAB Release Procedure p. 46
6.4.2.5 Service Request Initiated by MS Procedure p. 47
6.4.2.6 Service Request Initiated by Network Procedure p. 48
6.4.3 Charging (GTP-C option) p. 48
6.4.4 CAMEL Considerations (GTP-C option) p. 48
6.4.5 Lawful Interception (GTP-C option) p. 49
6.4.5.1 Lawful Interception of Content of Communications p. 49
6.4.5.2 Lawful Interception of Intercept Related Information p. 50
6.4.6 QoS Considerations (GTP-C option) p. 50
6.4.7 Information storage in PS-MGW (GTP-C option) p. 50
6.4.8 Abnormal Cases (GTP-C option) p. 51
6.5 General Lawful Interception Considerations p. 51
6.6 Security p. 52
6.7 O&M p. 52
6.8 RAN Considerations (e.g. GERAN) p. 52
6.9 Compatibility p. 52
6.10 Dynamic Allocation of PS-MGW Resources p. 52
6.11 Benefits and Drawbacks p. 53
6.12 Open Issues p. 54
7 Alternative 2: One Tunnel Approach p. 54
7.1 Introduction p. 54
7.1.1 Applicability p. 54
7.2 Logical Architecture p. 55
7.3 Mobility Management p. 59
7.3.1 Inter ISGSN Routeing Area Update p. 59
7.3.2 Location Report Procedure p. 61
7.3.3 Serving SRNS Relocation Procedure p. 62
7.3.4 Combined Hard Handover and SRNS Relocation Procedure p. 65
7.3.5 UMTS to GSM Change p. 65
7.3.6 GSM to UMTS SGSN Change p. 65
7.3.6.1 Intra SGSN Change p. 66
7.3.6.2 Inter SGSN Change p. 67
7.4 Session Management p. 71
7.4.1 PDP Context Activation Procedure p. 71
7.4.2 Secondary PDP Context Activation Procedure p. 73
7.4.3 Iu Release Procedure p. 74
7.4.4 Service Request Initiated by UE Procedure p. 74
7.4.5 Service Request Initiated by Network Procedure p. 75
7.5 Charging p. 77
7.6 CAMEL Considerations p. 77
7.7 Lawful Interception p. 78
7.8 QoS Considerations p. 78
7.9 Security p. 79
7.10 O&M p. 79
7.11 RAN Considerations (e.g. GERAN) p. 79
7.12 Abnormal Cases p. 79
7.13 Compatibility p. 79
7.14 Benefits and Drawbacks p. 79
7.15 Open Issues p. 80
8 Summary p. 80
8.1 Selection Criteria p. 80
8.1.1 Aims p. 80
8.1.2 Compatibility criteria p. 81
8.2 Assignment of Functions to the Logical Architecture p. 81
8.3 Comparison of the Overall Functionality p. 83
9 Work Plan p. 85
A Combined SGSN and GGSN split p. 86
A.1 Introduction p. 86
A.2 Logical Architecture p. 87
A.2.1 Functional Nodes p. 88
A.2.1.1 SGSN Server p. 88
A.2.1.2 GGSN Server p. 88
A.2.1.3 Packet Switching - Media Gateway (PS-MGW) p. 88
A.2.2 Interfaces p. 88
A.3 Benefits and Drawbacks p. 89
A.4 Open Issues p. 89
$ Change History p. 91
