RAN Assistance Information Timer for Wireless Cell Change

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing wireless communication systems face challenges in effectively handling radio access network (RAN) assistance information during cell changes, particularly in inter-RAT and intra-RAT transitions, where it is unclear when dedicated RAN assistance information remains valid, leading to inconsistencies in traffic steering between 3GPP and non-3GPP access networks.

Innovation Solution

A method is introduced where user equipment (UE) receives RAN assistance information with a timer value via dedicated signaling, allowing it to determine the validity of the information and apply it during cell changes. The UE starts a timer upon receiving the information and continues to apply the dedicated RAN assistance information until the timer expires, ensuring consistent interworking policies across different radio access technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated RAN assistance information is provided without a timer mechanism, then the information can be applied immediately, but it is unclear when the information remains valid during cell changes, leading to inconsistencies in traffic steering

Engineering Contradiction:
Improvevalidity of RAN assistance informationVSAvoidtimer management mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by including a timer value in the dedicated RAN assistance information before the UE actually needs to use it. This timer value pre-defines the validity period, so when the UE receives the information, it already knows how long to apply it, eliminating the uncertainty about validity duration during cell changes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by making the RAN assistance information time-dependent through the timer mechanism. The information is not statically valid indefinitely but dynamically expires after the timer value elapses, allowing the system to adapt to changing network conditions while providing clear validity boundaries.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If RAN assistance information is applied indefinitely, then consistency is maintained, but the system cannot adapt to changed network conditions after cell change

Engineering Contradiction:
Improveadaptation to network conditionsVSAvoidconsistency of traffic steering
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies periodic action through the timer mechanism that periodically expires and resets. The RAN assistance information remains valid for a specific period defined by the timer value, after which it expires and can be updated with new information better suited to current network conditions, enabling systematic adaptation while maintaining consistency during the validity period.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements parameter changes by using the timer value as a dynamic parameter that controls the validity duration of RAN assistance information. This allows the system to transition from static, indefinite validity to dynamic, time-limited validity, enabling adaptation to changing network conditions while maintaining reliability within each validity period.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a timer mechanism is introduced to track validity, then adaptability to cell changes is improved, but the complexity of handling RAN assistance information increases

Engineering Contradiction:
Improvehandling of cell changesVSAvoidtimer management in UE
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining the timer value with the RAN assistance information in a single dedicated signaling message. Instead of implementing a separate, complex timer management system in the UE, the timer value is integrated into the existing information structure, simplifying the overall handling mechanism while still providing the necessary adaptability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3120615B1Method and apparatus for handling ran assistance information for cell change in wireless communication system
Publication Date: 2019.08.14 LG ELECTRONICS INC
  • EP3120615B1 patent drawingFigure 1
  • EP3120615B1 patent drawingFigure 2
  • EP3120615B1 patent drawingFigure 3~5

AI summary

A method and apparatus for handling radio access network (RAN) assistance information in a wireless communication system is provided. A user equipment (UE) receives RAN assistance information via dedicated signaling, and starts a timer. Upon performing cell change, the UE determines whether to stop the timer. The cell change may be one of inter- or intra-radio access technology (RAT) cell change. If the UE determines not to stop the timer, the UE applies the received RAN assistance information while the timer is running. That is, the UE may consider that the received RAN assistance information is valid for RAN-assisted interworking while the timer is running.