Call Termination Anchoring in Circuit Switched Domain

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Solution Overview

Problem

Current call termination anchoring in circuit switched domains cannot be effectively anchored without intelligent network services or number portability, leading to disruptions in voice session continuity during network switching between IMS and circuit domain networks.

Innovation Solution

A method and system that enables call termination anchoring by having the home location register directly request and receive IP multimedia subsystem routing information from the voice call continuity application server, allowing the call to be anchored without relying on intelligent network services or number portability, involving steps like sending a LOCREQ message and returning IMS routing information to ensure continuous voice sessions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If intelligent network services or number portability are used for call termination anchoring, then voice session continuity is maintained during network switching, but device complexity and dependency on additional network services increase

Engineering Contradiction:

Improvevoice session continuityVSAvoidnetwork service dependency

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the anchoring function from the intelligent network domain and relocates it to the home location register (HLR) in the circuit switched domain. The HLR directly interacts with the voice call continuity application server to obtain routing information, eliminating the need for intelligent network services or number portability while maintaining voice session continuity during network switching

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The home location register (HLR) is enhanced to perform multiple functions: it not only manages subscriber location information but also directly requests and processes routing information from the voice call continuity application server. This multi-functionality allows the HLR to handle anchoring operations without requiring separate intelligent network infrastructure

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If intelligent network services are deployed for anchoring, then call termination can be anchored, but the solution becomes unsuitable for networks without intelligent network support

Engineering Contradiction:

Improvecall termination anchoring capabilityVSAvoidnetwork compatibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The solution makes the HLR universal by enabling it to directly interface with the voice call continuity application server regardless of whether intelligent network services are present. The HLR obtains routing information through direct interaction with the application server, making the anchoring capability applicable to both networks with and without intelligent network support

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces the home location register (HLR) as an intermediary between the circuit switched domain and the IP multimedia subsystem. The HLR mediates the anchoring process by directly requesting routing information from the voice call continuity application server, eliminating the need for intelligent network mediators and improving network compatibility

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the home location register directly requests routing information from the voice call continuity application server, then intelligent network services are not required, but new signaling interactions must be established

Engineering Contradiction:

Improvenetwork service independenceVSAvoidsignaling interaction complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the routing information request function from the intelligent network domain and places it directly in the home location register. The HLR sends routing information requests directly to the voice call continuity application server using existing signaling interfaces, avoiding the need for complex new signaling protocols while achieving service independence

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS7953072B2Method and system for ending-call anchoring of circuit switched domain

Publication Date: 2011.05.31 ZTE CORP

AI summary

The present invention discloses a method and a system for call termination anchoring of CS (Circuit Switching) domain, the method including the following steps: when a call coming from CS domain network reaches the mobile switch center in the home circuit switched domain of a voice call continuity subscriber, the mobile switch center sends a LOCREQ message to a home location register to query a location; Step 2, the home location register directly sends a message to the voice call continuity application server to request routing information; and Step 3, the voice call continuity application server returns IP multimedia subsystem routing number information associated with the voice call continuity application server to the home location register to make the call can be anchored to the voice call continuity application server. The present invention realizes call termination anchoring for a VCC subscriber in the circuit domain without intelligent network services.