Content for TR 23.843 Word version: 12.0.0
4 Scenarios and problem analysis for CNO
5 Architecture principles
6 Solutions targeting HLR/HSS overload handling
7 Solutions targeting improved efficiency of User Location Information reporting
7A Solutions targeting reporting list of users on the area(s) of interest
8 Solutions for GTP-c overload handling
9 Evaluation
10 Conclusions
A CN interfaces and services using Diameter as well as overload impact
$ Change history
4 Scenarios and problem analysis for CNO p. 9
4.1 General p. 9
4.2 Scenario 1: Overlaid RATs and failure of RAN node p. 10
4.3 Scenario 2: CN overload due to flood of registrations and mobility management events p. 10
4.4 Scenario 3: CN overload due to flood of resource allocation for mobile originating services p. 10
4.5 Scenario 4: CN overload due to flood of mobile terminated events p. 11
4.6 Scenario 5: CN overload due to flood of User Location Information (ULI) reporting p. 11
4.7 Scenario 6: User Location Information (ULI) reporting scenarios with existing capabilities p. 12
4.8 Scenario 7: ULI reporting when user plane radio bearers are not established for the UE p. 13
4.9 Scenario 8: GTP-C overload due to flood of Mobility and Session Management messages p. 13
5 Architecture principles p. 14
6 Solutions targeting HLR/HSS overload handling p. 15
6.1 Improved control of user registration attempts p. 15
6.1.1 Introduction p. 15
6.1.2 Solution 1: Optimizing the periodic LAU/RAU/TAU signalling p. 15
6.1.3 Solution 2: NAS reject solution p. 15
6.1.3.1 Evaluation p. 16
6.1.4 Ideas for RAN node restart CN overload prevention p. 16
6.1.5 Signalling load reduction for TAU/RAU caused by UE mobility across mobility management entities p. 17
6.2 Solutions targeting at HSS/HLR overload prevention p. 19
6.2.1 Introduction p. 19
6.2.2 Solution 1: Optimizing subscription data download from HSS p. 21
6.2.3 Solution 2: HLR/HSS overload notification p. 22
6.2.4 Solution 3: Prevent HLR/HSS from overload due to RAT-reselection in PS domain p. 23
6.2.4.1 General p. 23
6.2.4.2 Evaluation p. 23
6.2.5 Solution 4: Diameter application evaluation and improvement via existing mechanisms p. 24
6.3 Solution: Optimizing control of mobile terminated services by CN node p. 26
7 Solutions targeting improved efficiency of User Location Information reporting p. 26
7.1 Solution 1: ULI reporting only when the UE is in "CONNECTED" state p. 26
7.1.1 Description p. 26
7.1.2 Impacts on existing nodes and functionality p. 26
7.1.3 Solution evaluation p. 26
7.2 Solution 2: ULI reporting at PCC area level p. 27
7.2.1 Overview of ULI reporting at PCC area level p. 27
7.2.2 More detailed description p. 28
7.2.3 Impacts on existing nodes and functionality p. 29
7.2.4 Solution evaluation p. 29
7.3 Solution 3: New "change of eNB" reporting event p. 30
7A Solutions targeting reporting list of users on the area(s) of interest p. 31
8 Solutions for GTP-c overload handling p. 33
8.1 Solutions targeting existing mechanism for GTP-C node overload prevention p. 33
8.1.1 Introduction p. 33
8.1.2 Mobility management signalling p. 33
8.1.3 Re-attach signalling p. 33
8.1.4 Service request signalling p. 33
8.1.5 UE requested PDN connectivity signalling p. 34
8.1.6 Network triggered Service Requests p. 34
8.2 Framework for solutions using modifications of GTP-c signalling p. 34
8.2.1 General p. 34
8.2.2 List of interfaces (and directions) where each of GTP-c load and overload control should apply p. 35
8.2.3 Scope of GTP-c load / overload control p. 35
8.2.4 Examples of actions GTP-c node may take when another node has advertised overload p. 36
8.2.5 Solution 1: Using load information for dynamic load balancing of GW nodes p. 36
8.2.5.1 Description p. 36
8.2.5.2 Applicability p. 36
8.2.5.3 Messages and inclusion period p. 37
8.2.5.4 Node selection using load information p. 37
8.2.5.5 Advertising support of this feature p. 38
8.2.5.6 Roaming consideration p. 38
8.2.5.7 Network sharing support p. 38
8.2.6 Solution 2: Using overload information for overload control of GTP-C nodes p. 38
8.2.6.1 Description p. 38
8.2.6.2 Applicability p. 39
8.2.6.3 Messages and inclusion period p. 39
8.2.6.4 Expected actions from involved nodes when overload information is received p. 40
8.2.6.5 Advertising support of this feature p. 40
8.2.6.6 Roaming consideration p. 40
8.2.6.7 Network sharing support p. 40
8.3 Solutions for preventing S-GW and P-GW overload p. 40
9 Evaluation p. 42
9.1 Evaluation of SS7/ MAP interface p. 42
9.2 Enhancement of Diameter interface for overload prevention and control support p. 42
9.3 Evaluation related with the support of overload control and dynamic load control for GTP-C p. 43
9.4 Evaluation related with the support of User Location Information reporting improvements p. 44
9.5 Evaluation related with the support of reporting list of users on the area(s) of interest p. 45
10 Conclusions p. 45
10.1 Conclusions for MAP/SS7 and Diameter interfaces p. 45
10.1.1 MAP/SS7 interface p. 45
10.1.2 Diameter interface p. 45
10.2 Conclusions for GTP-C interfaces p. 45
10.3 Conclusions for User Location Information reporting improvements p. 46
A CN interfaces and services using Diameter as well as overload impact p. 47
$ Change history p. 48
