IMS Control Entity Default CSI Handling

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Solution Overview

Problem

IMS networks face challenges in processing session requests without a valid Communication Service Identifier (CSI), as legacy terminals may not support CSI or generate unrecognized CSI, leading to unclear service execution by network nodes.

Innovation Solution

Implementing a default CSI procedure within control entities like P-CSCF and S-CSCF, which generate or enforce default CSI information during user terminal registration, allowing nodes to identify and process communication services correctly, even if CSI is missing, unsupported, or unrecognized.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If legacy terminals are used that do not support CSI, then compatibility with older devices is improved, but the ability to properly identify and process communication services deteriorates

Engineering Contradiction:
Improvecompatibility with legacy terminalsVSAvoidCSI information
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The network elements perform preliminary actions by generating default CSI information during the user terminal registration process, before actual session requests are made. This ensures that when legacy terminals make service requests without CSI, the network already has default values ready to use for service identification and processing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Default CSI information acts as an intermediary between legacy terminals that cannot provide CSI and the network elements that require CSI for service processing. The HSS generates and stores default CSI, which is then used by P-CSCF and S-CSCF to properly identify and route communication services for terminals that otherwise would be unable to do so.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If default CSI procedure is implemented, then service identification accuracy is improved, but network complexity increases

Engineering Contradiction:
Improveservice identification accuracyVSAvoidnetwork complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The HSS automatically generates default CSI information based on user subscription data during registration, without requiring manual configuration or complex external intervention. This self-service approach simplifies the overall system by having one network element handle the generation and distribution of default CSI to other elements as needed.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2179569B1Control entity and method for setting up a session in a communications network, subscriber database and communications network
Publication Date: 2016.05.04 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2179569B1 patent drawingFigure 1~2a
  • EP2179569B1 patent drawingFigure 2b~2c
  • EP2179569B1 patent drawingFigure 3~4

AI summary

Control entity and method for setting up a session in a communications network, subscriber database and communications network The invention relates to a control entity for setting up a session in a communications network, comprising an input device for receiving a request to set up a session in the communications network, a processor unit for processing the request, and an output device for sending messages. The control entity further comprising or having access to a memory for storing information. The processor unit is arranged to determine if the request comprises a valid Communication Service Identifier, CSI, the Communication Service Identifier identifying the type of communication service of the session that is to be established over the communications network. And if the request does not comprise a valid Communication Service Identifier to execute a default CSI procedure using default CSI information stored in the memory.