PLMN Selection Search Inhibit List for Roaming Battery Conservation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Mobile communication devices face inefficiencies in network scanning while roaming, as they periodically search for higher priority networks, leading to increased battery consumption and longer search times due to the complexity of available access technologies and frequency bands, especially when no higher priority networks are available.

Innovation Solution

Implementing a search inhibit list mechanism in mobile devices that tracks unavailable networks, allowing them to refrain from periodic scans when no higher priority networks are found, thereby reducing unnecessary searches and conserving resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mobile devices periodically scan for higher priority networks while roaming, then network selection reliability is improved, but battery consumption increases and search time extends

Engineering Contradiction:
Improvenetwork selection reliabilityVSAvoidbattery consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent performs network scanning and availability determination in advance before final network selection. By periodically determining whether higher priority networks are available and storing these results, the device avoids repeated full scanning procedures, thereby reducing battery consumption while maintaining reliable network selection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of performing complete network scanning procedures repeatedly, the patent implements a simplified check to determine network availability. This partial action approach verifies whether higher priority networks are available without executing the full scanning process, thus conserving energy while ensuring network selection reliability.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If mobile devices periodically scan for higher priority networks while roaming, then network selection reliability is improved, but search time increases

Engineering Contradiction:
Improvenetwork selection reliabilityVSAvoidsearch time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs network availability determination in advance and stores the results. When network reselection is needed, the device retrieves previously stored availability information rather than performing complete scans, significantly reducing search time while maintaining reliable network selection through prior verification.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a simplified availability check instead of complete network scanning. This partial action determines whether higher priority networks are available without executing full scan procedures, thereby reducing search time while preserving network selection reliability.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If mobile devices perform complete network scanning procedures, then accurate network availability determination is achieved, but energy consumption and processing time increase

Engineering Contradiction:
Improvenetwork availability determination accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent performs a simplified availability check that determines whether higher priority networks are available without executing complete scanning procedures. This partial action maintains sufficient accuracy for network selection decisions while significantly reducing energy consumption and processing requirements.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs availability determination in advance and caches the results. This preliminary action ensures accurate network availability information is obtained before selection, eliminating the need for repeated complete scans and thereby reducing energy consumption while maintaining determination accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2774419B1Public land mobile network PLMN selection
Publication Date: 2016.03.02 BLACKBERRY LTD
  • EP2774419B1 patent drawingFigure 1
  • EP2774419B1 patent drawingFigure 2
  • EP2774419B1 patent drawingFigure 3

AI summary

Methods and apparatus for network searching are disclosed. An example method is performed by a mobile device related to public land mobile network PLMN selection, the method comprising registering with a visited PLMN (502), determining whether a priority search inhibit list includes a cell global identity of a serving cell (504), dependent at least in part on determining that the priority search inhibit list does not include the cell global identity of the serving cell and dependent at least in part on a priority search period, searching for a second PLMN having a higher priority than the visited PLMN (506), and dependent at least in part on the searching being unsuccessful (508), adding the cell global identity of the serving cell to the priority search inhibit list (512).