Content for TR 23.857 Word version: 11.0.0
1 Scope
2 References
3 Definitions, symbols and abbreviations
4 Requirements analysis and assumptions
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1 Scope p. 8
The present document contains the study on EPC nodes failure and restoration.
This document will consider any necessary operational protocol recovery mechanisms in the EPS in order to restore the subscriber service in the event of EPC node failure or clean up the hanging resource in other EPC nodes if the recovery of the failed node is not possible. The document will address the following aspects:
- list the different network failure scenarios to be analyzed for EPC nodes: MME, S4-SGSN, SGW and PGW;
- identify precisely the problems resulting from the current definition of the standards;
- list various possible solutions;
- identify pros and cons of possible solutions;
- conclude on potential enhancements to the standards (depending on gains vs complexity).
2 References p. 8
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
[1]
TR 21.905: "Vocabulary for 3GPP Specifications".
[2]
TS 23.007: "Restoration procedures".
[3]
TS 29.274: "Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3".
[4]
TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS)".
[5]
TS 24.008: "Mobile Radio Interface Layer 3 specification; Core Network Protocols; Stage 3".
[6]
TS 23.401: "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".
[7]
TS 23.060: "General Packet Radio Service (GPRS); Service description".
[8]
TS 23.272: "Circuit Switched (CS) fallback in Evolved Packet System (EPS); Stage 2".
[9]
TS 29.118: "Mobility Management Entity (MME) - Visitor Location Register (VLR) SGs interface specification".
[10]
TS 23.018: "Basic call handling; Technical realization".
[11]
TS 23.236: "Intra Domain Connection of RAN Nodes to Multiple CN Nodes".
3 Definitions, symbols and abbreviations p. 9
3.1 Definitions p. 9
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
3.2 Abbreviations p. 9
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
EPC
Evolved Packet Core
EPS
Evolved Packet System
GTP
GPRS Tunnelling Protocol
MME
Mobility Management Entity
PGW
PDN Gateway
SGW
Serving Gateway
4 Requirements analysis and assumptions p. 9
The following are the requirements considered as the criteria for developing solutions provided in this study.
- The impact or degradation of the service affect on the user shall be minimised.
- The solution shall not cause overload or congestion in the Core Network and RAN.
- The solution shall support pre-Rel10 UEs but not necessary with the same level of efficiency and performance to that provided for UEs from Rel-10 onwards.
- The solution should minimise the resource reservation in the Core Network and RAN.
- The impact for the hPLMN by EPC node failure of vPLMN shall be minimised.
- The deployment of LTE/EPC and SGs interface shall not impair the delivery of Mobile Terminated CS services (e.g. CS call, SMS).
