BGCF Inter-IMS Service Support via SIP Modification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Inter-IMS service support in telecommunication systems is challenging due to differences in communication providers' networks, where multimedia calls and communications need to be set up between IMS systems of different providers, requiring efficient handling of SIP requests and feature tags to ensure compatibility and proper routing.

Innovation Solution

The implementation of a border gateway control function (BGCF) that forwards, modifies, and routes SIP requests between IMS networks, determining method and feature tag support, adding or removing codecs, and altering routing information to ensure compatibility and successful communication across different IMS systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If SIP requests are forwarded between IMS networks of different providers, then inter-IMS service support is enabled, but compatibility issues arise due to differences in network capabilities and supported features

Engineering Contradiction:
Improveinter-IMS service supportVSAvoidcompatibility
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a border gateway control function (BGCF) as an intermediary between IMS networks of different providers. The BGCF receives SIP requests, determines whether the requesting or receiving network supports the requested method and feature tags, and modifies the request accordingly. This intermediary resolves compatibility issues by mediating between networks with different capabilities, enabling inter-IMS service support while maintaining reliability through active compatibility management.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If feature tags are added or removed from SIP requests to match external IMS capabilities, then compatibility is improved, but processing complexity increases

Engineering Contradiction:
ImprovecompatibilityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the border gateway control function determine support for methods and feature tags before forwarding SIP requests between IMS networks. The BGCF proactively identifies capability mismatches and modifies feature tags in advance, preventing compatibility issues rather than reacting to them. This preliminary processing reduces the need for complex real-time negotiation and error handling, managing processing complexity through advance preparation.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If routing information is modified to comply with external IMS capabilities, then successful communication is enabled, but message modification overhead increases

Engineering Contradiction:
Improvecommunication successVSAvoidmessage modification overhead
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The border gateway control function serves as a mediator that handles routing information modification centrally at the network boundary. Rather than requiring multiple modification attempts or complex peer-to-peer negotiation between IMS networks, the BGCF single-handedly adjusts routing information to ensure compatibility. This centralized mediation enables successful communication while minimizing time loss by avoiding repeated modification cycles.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3266187B1Inter-IMS service support in telecommunication systems
Publication Date: 2020.04.08 T MOBILE US INC
  • EP3266187B1 patent drawingFigure 1
  • EP3266187B1 patent drawingFigure 2
  • EP3266187B1 patent drawingFigure 3

AI summary

A first communication provider supports an IP multimedia subsystem (IMS) having a border session control function (BGCF) that receives SIP requests. The SIP requests correspond to different SIP methods and specify various feature tags. The feature tags correspond to available services or media types that may be available from the IMS of a second communication provider. When receiving a SIP request that addresses a user supported by the second communication provider, the BGCF of the first communication provider checks the method and feature tag of the SIP request to make sure that they are supported by IMS of the second communication provider. If they are not, the SIP is rejected and failure message is returned. The BGCF may also modify certain parameters of the SIP request, such as by removing one or more offered codecs or preconditions.