Call Re-establishment Signal Threshold Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing call re-establishment algorithms in GSM networks do not allow network operators to specify minimum radio channel quality criteria for initiating call re-establishment after a radio link failure, leading to inefficient re-establishment attempts in poor channel quality conditions, which can result in unnecessary signaling and processing overhead.

Innovation Solution

Implementing a signal level threshold in each network cell, where call re-establishment is initiated only if the received signal level exceeds a predefined minimum threshold, thereby minimizing instances of failed re-establishment attempts and optimizing network resource use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If call re-establishment is enabled without signal level threshold criteria, then the probability of dropped voice calls is minimized, but unnecessary signaling and processing overhead occurs in poor channel quality conditions

Engineering Contradiction:
Improvecall continuityVSAvoidnetwork resource consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces a signal level threshold parameter that must be satisfied before call re-establishment is initiated. This parameter change filters out re-establishment attempts in poor channel conditions, reducing unnecessary network signaling and processing while maintaining reliability in suitable conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from signal level measurements to control the call re-establishment process. By continuously monitoring signal quality and comparing it against the threshold, the network can intelligently decide whether to permit re-establishment, avoiding waste of resources in poor conditions while maintaining service in good conditions.

Inventive Principle:
Principle #23Feedback

2Loss of energy

If call re-establishment is disabled to minimize network resource use, then signaling overhead is reduced, but user experience deteriorates with increased call drops

Engineering Contradiction:
Improvenetwork resource consumptionVSAvoidcall continuity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

By introducing and adjusting the signal level threshold parameter, the system finds an optimal balance between resource conservation and service reliability. The threshold can be tuned to allow re-establishment only when signal conditions indicate a reasonable chance of success, thereby reducing unnecessary resource consumption while maintaining user experience.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If call re-establishment attempts are made in poor channel quality conditions, then call continuity is maintained, but success probability decreases and network resources are wasted

Engineering Contradiction:
Improvecall re-establishment availabilityVSAvoidre-establishment success rate
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent uses signal level threshold as a gatekeeping parameter that must be satisfied before re-establishment proceeds. This ensures that re-establishment attempts are only made when channel conditions are sufficiently good, thereby maintaining high success rates while preserving call continuity availability when conditions permit.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2471335B1System and method for call re-establishment
Publication Date: 2019.10.09 BLACKBERRY LTD
  • EP2471335B1 patent drawingFigure 1
  • EP2471335B1 patent drawingFigure 2
  • EP2471335B1 patent drawingFigure 3

AI summary

A method for implementing call re-establishment using a user equipment (UE) configured to communicate with a wireless communication network includes detecting at least one of a radio link failure and a protocol failure of a connection between the UE and a serving cell. A target cell of the wireless communication network is selected and a received signal level for the target cell is compared to a signal level threshold. When the received signal level for the target cell exceeds the signal level threshold, call re- establishment is initiated on the target cell. The signal level threshold may be encoded within a system information type 21bis message, or a system information element. In some cases, the signal level threshold is equal to a minimum signal level required on the target cell.