IMS S-CSCF Reassignment for Load Balancing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In IMS networks, when a preferred S-CSCF becomes unavailable or is recovered, there is no mechanism to reassign users back to it, leading to inefficient load balancing and resource utilization, especially when new S-CSCFs are deployed or existing ones are under maintenance.

Innovation Solution

A method and system that allow the I-CSCF or S-CSCF to receive signaling messages indicating the availability of a more favorable S-CSCF, determining if conditions for reallocating a user are met, such as the absence of active sessions or subscriptions, and reassigning users to optimize load balancing by moving them to a more suitable S-CSCF.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a user is assigned to a backup S-CSCF when the preferred S-CSCF is unavailable, then service continuity is maintained, but load balancing efficiency deteriorates when the preferred S-CSCF recovers

Engineering Contradiction:
Improveservice continuityVSAvoidload balancing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic S-CSCF reassignment by introducing a reassignment indicator that allows the system to transition from a static assignment to a dynamic reassignment process. When the preferred S-CSCF recovers, the system can dynamically reassign the user back to it, optimizing load balancing while maintaining service continuity during outages.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms through the reassignment indicator and availability checking process. The system continuously monitors S-CSCF availability and uses this feedback to make intelligent reassignment decisions, ensuring users are assigned to the most appropriate S-CSCF based on current network conditions.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If S-CSCF reselection is prevented while the current S-CSCF is available, then service stability is maintained, but adaptability to new S-CSCF deployments deteriorates

Engineering Contradiction:
Improveservice stabilityVSAvoidadaptability to new S-CSCF
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The system transitions from a static no-reassignment policy to a dynamic conditional reassignment policy. The reassignment indicator and availability checking enable the system to adapt its behavior based on network conditions, allowing reassignment when beneficial while maintaining stability when appropriate.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the system parameter from a fixed assignment state to a conditional reassignment state. By introducing the reassignment indicator and availability conditions, the system can adjust its assignment behavior based on changing network parameters such as S-CSCF availability and load conditions.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If users remain assigned to the original S-CSCF after recovery, then assignment consistency is maintained, but resource utilization efficiency deteriorates

Engineering Contradiction:
Improveassignment consistencyVSAvoidresource utilization efficiency
Core Design Contradiction:
Loss of informationVSLoss of energy

Solution Approach 1:

The system uses feedback from S-CSCF availability checking to make informed reassignment decisions. This feedback mechanism ensures that reassignment only occurs when the preferred S-CSCF is actually available, maintaining assignment consistency while improving resource utilization by preventing unnecessary assignments to unavailable resources.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary availability checking before reassignment. By checking S-CSCF availability in advance and setting the reassignment indicator accordingly, the system ensures that reassignment only happens when the target S-CSCF is ready to accept the user, maintaining consistency while optimizing resource use.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2066098B1Allocation of a serving entity in a communication network
Publication Date: 2016.05.25 NOKIA SOLUTIONS & NETWORKS OY
  • EP2066098B1 patent drawingFigure 1
  • EP2066098B1 patent drawingFigure 2
  • EP2066098B1 patent drawingFigure 3

AI summary

The present invention relates to allocating a serving entity (S-CSCF) for a user of IMS network. Signaling message associated with the user is received and the message comprises information indicating that the user may be allocated to another serving entity. It is determined if at least one condition for allocation of another serving entity for the user is met.