Cell Reselection Algorithm Offset for Radio Access Network Ping-Pong

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Solution Overview

Problem

Mobile telecommunications devices experience 'ping-ponging' between radio access networks due to ineffective cell reselection strategies, leading to service disruptions and inefficiencies in UMTS and GSM systems.

Innovation Solution

Implementing an algorithm that imports system information from one radio access network to another and applies an offset to cell reselection measurements to determine the likelihood of reselection, thereby reducing the likelihood of 'ping-ponging' by ranking cells and reselecting only suitable networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cell reselection parameters are applied without network-specific offsets, then cell reselection is straightforward, but ping-ponging between radio access networks occurs frequently

Engineering Contradiction:
Improveconnection stabilityVSAvoidcell reselection algorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different offset values specifically for each radio access network (GSM and UMTS) based on local network characteristics. By tailoring the offset to each network type rather than using a universal approach, the system reduces ping-ponging while maintaining manageable algorithm complexity through network-specific parameterization.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies cell reselection parameters by introducing network-specific offset values that change the selection criteria. These parameter changes allow the device to make more informed reselection decisions that prevent ping-ponging, balancing connection stability with acceptable algorithm complexity through mathematical adjustments.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If cell reselection uses standard parameters without additional weight values, then the algorithm is simpler, but service disruptions increase due to ineffective reselection

Engineering Contradiction:
Improveservice continuityVSAvoidreselection algorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary calculations by determining additional weight values before executing cell reselection. These pre-computed weights are then used to adjust the reselection decision, ensuring more reliable service continuity while keeping the overall algorithm complexity manageable through structured preparation steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent incorporates feedback mechanisms where the device monitors service quality and uses this information to adjust reselection behavior. By feeding back service disruption information and adjusting future reselection decisions accordingly, the system improves service continuity while managing complexity through iterative optimization.

Inventive Principle:
Principle #23Feedback

3Productivity

If the device reselects cells based on basic measurement criteria, then the process is faster, but ping-ponging frequency increases

Engineering Contradiction:
Improvereselection speedVSAvoidconnection stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by using offset values and weight calculations to prevent ping-ponging before it occurs. These preemptive adjustments to reselection criteria stop the oscillation between networks from happening in the first place, maintaining connection stability while keeping the enhanced reselection process computationally efficient.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP2146540B1A method of cell reselection in a wireless telecommunications device operative with a plurality of a radio access networks
Publication Date: 2010.10.06 BLACKBERRY LTD
  • EP2146540B1 patent drawingFigure 1
  • EP2146540B1 patent drawingFigure 2
  • EP2146540B1 patent drawingFigure 3

AI summary

Apparatus and a method of cell reselection in a wireless telecommunications device operative with a plurality of radio access networks are disclosed. The method comprises, when the device is camped on a first radio access network: ranking cells in a neighbouring list according to cell reselection criteria; considering for cell reselection a cell in the neighbouring list; when the cell in the list is a cell of a second radio access network different from the first radio access network, applying an algorithm for cell reselection from the second radio access network to the first radio access network; and when the algorithm as applied would result in reselection to the first radio access network, considering for cell reselection another cell in the list.