UE Radio Capability Conversion for Cross-RAT Handover Signalling

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Solution Overview

Problem

Existing systems face inefficiencies in signaling UE radio capability information across different radio access technologies (RATs) during handovers, particularly for 4G and 5G networks, as target RAN nodes lack the capability to decode UE radio capability information formatted for the source RAT.

Innovation Solution

A method and apparatus that enables a RAN node to generate and transmit UE radio capability information in both the format of the source and target RATs, allowing for efficient conversion and storage of this information using a UE Radio Capability ID (RAC-ID) within the core network, maintaining the 'source adapt to target' principle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If signalling is transmitted at every cell boundary in a Hierarchy Level 1 (HL1) configuration, then coverage is improved, but signalling overhead and resource consumption increase significantly

Engineering Contradiction:
ImprovecoverageVSAvoidsignalling overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the coverage area into different zones (first coverage area and second coverage area) with different signalling transmission strategies. In the first coverage area, signalling is transmitted at every cell boundary, while in the second coverage area, signalling is transmitted only at selected cell boundaries based on whether user equipment is present. This segmentation allows the system to maintain reliable coverage where needed while reducing signalling overhead in areas where it is not necessary.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different signalling transmission qualities to different locations. In coverage areas where user equipment is detected, signalling is transmitted at every cell boundary to ensure reliable communication. In coverage areas where no user equipment is present, signalling transmission is reduced to selected cell boundaries. This local differentiation optimizes the balance between coverage reliability and signalling overhead based on actual network conditions.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If user equipment presence is determined by checking all possible cell boundaries, then detection accuracy is improved, but processing time and complexity increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by determining user equipment presence in a first coverage area before making signalling transmission decisions for a second coverage area. This preliminary detection allows the system to prepare transmission configurations in advance, reducing the need for real-time processing of all cell boundaries and thereby reducing overall processing time while maintaining detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts and focuses processing efforts on specific cell boundaries where user equipment is likely to be present, rather than uniformly processing all cell boundaries. By identifying and concentrating resources on relevant detection points based on preliminary information, the system achieves accurate detection with reduced processing time and complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4104472B1Signalling optimisation
Publication Date: 2026.05.13 NOKIA TECHNOLOGIES OY
  • EP4104472B1 patent drawingFigure 1
  • EP4104472B1 patent drawingFigure 2A
  • EP4104472B1 patent drawingFigure 2B

AI summary

There is disclosed an apparatus comprising means for performing: receiving first radio capability information from a user equipment, the first radio capability information in a format of a first radio access technology; generating second radio capability information of the user equipment based on the first radio capability information, wherein the second radio capability information is generated in a format of a second radio access technology; and sending the first radio capability information and the second radio capability information to a core network node.