Voice Session Handover via Target Core Network Selection

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Solution Overview

Problem

Current communication networks lack a defined procedure to ensure successful handover of voice sessions from a packet switched source radio access network to a target radio access network associated with a circuit switched domain, leading to potential disruptions in voice session continuity.

Innovation Solution

A method and node for selecting a target core network that supports voice session continuity, involving the reception and selection of network identifications indicating support for voice session continuity, allowing for dynamic and dedicated handover of voice sessions from a packet switched source radio access network to a target radio access network with a circuit switched domain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If handover procedure is implemented without defined selection criteria for target core network, then handover can be executed, but voice session continuity cannot be guaranteed

Engineering Contradiction:
Improvevoice session continuityVSAvoidhandover procedure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring the source radio access network node with a list of candidate target core networks and their identifiers before handover is needed. This allows the node to quickly select an appropriate target during handover without complex real-time decision-making, thereby ensuring voice session continuity while maintaining procedural simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism in the form of a pre-defined candidate target core network list that mediates between the source radio access network and potential target networks. This intermediary structure simplifies the handover procedure by providing a curated selection of suitable targets rather than requiring direct complex interactions between multiple networks during the handover process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If generic handover procedure is used, then handover can be performed, but specific network architecture changes and operator policies cannot be accommodated

Engineering Contradiction:
Improvenetwork architecture adaptabilityVSAvoidselection procedure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring the source radio access network node with a list of candidate target core networks and their identifiers before handover is needed. This allows the node to quickly select an appropriate target during handover without complex real-time decision-making, thereby ensuring voice session continuity while maintaining procedural simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by incorporating specific identifiers and characteristics of candidate target core networks into the pre-configured list. This allows the handover procedure to adapt to different network architectures and operator policies by selecting targets based on matched parameters such as network type, supported services, and operator-specific criteria, without increasing overall procedure complexity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If network identification indicating voice session continuity support is received and used for selection, then reliable target core network selection is achieved, but additional signaling and processing are required

Engineering Contradiction:
Improvetarget core network selection reliabilityVSAvoidselection processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-configuring the source radio access network node with a list of candidate target core networks and their identifiers before handover is needed. This allows the node to quickly select an appropriate target during handover without complex real-time decision-making, thereby ensuring voice session continuity while maintaining procedural simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies beforehand cushioning by pre-processing and validating the candidate target core network list in advance, including verifying their support for voice session continuity. This preparatory work cushions against potential selection failures during actual handover, ensuring reliable target selection while minimizing processing time during the critical handover moment.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3073787B1Methods of and nodes for selecting a target core network for handing over a voice session of a terminal
Publication Date: 2018.12.19 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3073787B1 patent drawingFigure 1
  • EP3073787B1 patent drawingFigure 2
  • EP3073787B1 patent drawingFigure 3

AI summary

A method of selecting a target core network (110) of a communication network (100) for handing over a voice session of a terminal (118) from a packet switched source radio access network (104) of the communication network (100) to a target radio access network of the communication network (100) is described. The voice session is anchored in an Internet Protocol Multimedia Subsystem of the communication network (100), and the selected target core network (110) comprises a circuit switched domain which is associated with the target radio access network and supports voice session continuity allowing to hand over the voice session from the packet switched source radio access network (104) to the target radio access network. The target radio access network is associated with a network identification of the target core network (110). The method is executed by a node (112) of the source radio access network (104). The method comprises receiving (126) a network identification of at least one target core network (110) associated with at least one target radio access network. The network identification indicates support for voice session continuity. The method comprises selecting (138) the target core network (110) based on the indicated support of voice session continuity indicated by the received network identification. Thus, a successful handover of the terminal (118) from the packet switched source radio access network (104) to the target radio access network employing voice session continuity may be accomplished.