Network Node Time Offset Management via Mobility Profile

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Solution Overview

Problem

Current wireless communication systems lack a dynamic mechanism to account for user equipment mobility when managing time offset measurements, leading to potential inaccuracies in target cell identification during mobility procedures.

Innovation Solution

A method and network node configuration that obtain user equipment time offset measurements and mobility profiles to adapt parameters for detecting uplink signals, ensuring measurement reliability by accounting for expected mobility behavior, and sending indications to target nodes to adjust detection parameters accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If user equipment time offset measurement is used for target cell identification during mobility procedures, then mobility support is improved, but measurement accuracy deteriorates due to user equipment mobility

Engineering Contradiction:
Improvemobility supportVSAvoidtime offset measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The source RNC calculates an expected time offset value in advance based on the UE mobility profile before the handover is executed. This preliminary calculation allows the target RNC to have an accurate reference value ready when the UE arrives, compensating for the time that would otherwise have passed and caused measurement inaccuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The UE mobility profile acts as an intermediary that bridges the gap between the source RNC's knowledge of UE movement characteristics and the target RNC's need for accurate time offset prediction. This intermediary information allows the system to anticipate and compensate for measurement inaccuracies caused by UE mobility.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If static time offset measurement is used, then measurement simplicity is improved, but reliability deteriorates due to changing mobility conditions

Engineering Contradiction:
Improvemeasurement mechanism complexityVSAvoidmeasurement reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system transitions from a static time offset measurement approach to a dynamic one by incorporating the UE mobility profile. The mobility profile contains dynamic characteristics such as velocity and direction that allow the time offset to be adjusted based on current mobility conditions, thereby maintaining reliability without excessive complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter used for time offset calculation from a static measured value to a dynamically calculated expected value based on mobility profile parameters (velocity, direction, timing). This parameter change allows the system to adapt to varying mobility conditions while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2904835B1A node and method for the management of a user equipment time offset measurement
Publication Date: 2019.07.31 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2904835B1 patent drawingFigure 1
  • EP2904835B1 patent drawingFigure 2
  • EP2904835B1 patent drawingFigure 3

AI summary

Example embodiments presented herein are directed towards a network node (401A, 401B) (e.g., a source or target base station), and corresponding method therein, for managing a user equipment time offset measurement by accounting for a user equipment mobility profile. The management may involve a source network node (401A) delaying or preventing the sending of a user equipment timing offset measurement to a target network node (401B) or sending an indication or a reliability of the user equipment timing offset measurement. The network node (401A, 401B) may further apply a compensation to the user equipment timing offset measurement to account for an expected behavior of the user equipment based on the mobility profile. The network node (401A, 401B) may also adapt an uplink search window based on the user equipment mobility profile.