MGCF Capability Interworking via SIP Application Server

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Solution Overview

Problem

Conventional Media Gateway Control Functions (MGCF) lack the ability to convert and transfer capability information between Circuit-Switched (CS) and Internet Protocol Multimedia Subsystem (IMS) sessions, preventing direct IMS connections between CS-capable and IMS-only User Equipments (UEs).

Innovation Solution

A method and system for processing capability information within the MGCF, involving the creation and transmission of Session Initiation Protocol (SIP) messages that include capability information, allowing for the interworking between CS and IMS UEs, enabling the MGCF to convert and transfer this information between UEs, and utilizing SIP Application Servers to manage and correct capability information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the MGCF converts CS-call setup messages to SIP messages, then interworking between CS and IMS domains is enabled, but the MGCF cannot transfer capability information from CSI UEs to IMS UEs

Engineering Contradiction:

Improveinterworking capability between CS and IMS domainsVSAvoidcapability information transfer

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent introduces an Application Server as an intermediary entity between the MGCF and IMS UEs. The Application Server receives capability information from the MGCF, processes and stores it, and makes it available to IMS UEs through SIP messages. This intermediary resolves the contradiction by providing a mechanism for capability information transfer that the direct MGCF-to-IMS interface cannot provide.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary action by having the MGCF extract and forward capability information from CS-call setup messages to the Application Server before the actual IMS session establishment. This advance preparation ensures that capability information is available when needed for IMS session setup, preventing information loss in the conversion process.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If capability information is extracted from CS-call setup messages, then capability exchange between UEs is enabled, but the conventional MGCF lacks conversion methods for this information

Engineering Contradiction:

Improvecapability exchange reliabilityVSAvoidMGCF conversion function

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies extraction by separating the capability information processing function from the MGCF and placing it in the Application Server. The MGCF extracts capability information from CS-call setup messages and forwards it to the Application Server, which then handles the conversion and storage. This extraction resolves the contradiction by removing the conversion complexity from the MGCF while maintaining reliable capability exchange.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The Application Server acts as an intermediary that handles the complex conversion of capability information between different formats (CS domain format to IMS domain format). This mediator approach enables reliable capability exchange without requiring the MGCF to implement complex conversion functions, thus resolving the contradiction between reliability and device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If direct IMS connection is established between CSI UE and IMS UE, then service efficiency is improved, but capability information cannot be exchanged without MGCF conversion

Engineering Contradiction:

Improveservice efficiencyVSAvoidcapability information

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent implements feedback by having the Application Server store capability information received from the MGCF and provide it back to IMS UEs during session establishment. This feedback mechanism ensures that capability information is not lost in the transition from CS to IMS domain, enabling efficient direct connections while maintaining information completeness.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary action by pre-processing and storing capability information in the Application Server before the IMS session is established. This ensures that when the direct IMS connection is formed between CSI UE and IMS UE, the necessary capability information is already available, preventing information loss and maintaining high service efficiency.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2843907B1Method and System of Forwarding Capability Information of User Equipment in Internet Protocol Multimedia Subsystem Network

Publication Date: 2016.12.07 SAMSUNG ELECTRONICS CO LTD

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AI summary

Disclosed is a method and system for mutually exchanging capability information of UEs for communication between a Circuit-Switched (CS) and IMS services (CSI) UE, which can use a CS call for voice communication while using an IMS session for PS service, and an IMS UE which uses an IMS session for both voice communication and PS service. A MGCF performs interworking of capability information between a CS message and an IMS message so that the IMS UE can process UE capability information through an IMS session request/response. When a call request message containing no capability information is created from a UE not supporting capability exchange, a CSI AS transfers the call request message to a peer UE after inserting estimable capability information of the UE into the call request message, and stores capability information of the counterpart UE for the UE.