NTN Measurement Timing for Reliable Neighbor Cell SSB Alignment

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Solution Overview

Problem

Existing measurement configurations in non-terrestrial networks (NTN) struggle to align synchronization signal block (SSB) based measurement timing configurations (SMTC) and measurement gaps due to large and changing propagation delays caused by satellite mobility, leading to unreliable neighbor cell measurements.

Innovation Solution

Implement mechanisms for determining and updating SMTC and measurement gap configurations on a per-cell basis, using position-velocity-time (PVT) information and orbital ephemeris to align with SSB signals, and employing additional SSB bursts to maintain synchronization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed measurement timing configurations are used in NTN, then device complexity is reduced, but measurement reliability deteriorates due to large and changing propagation delays from satellite mobility

Engineering Contradiction:

Improvemeasurement configuration complexityVSAvoidneighbor cell measurement reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic measurement timing configurations that adapt to changing satellite positions and propagation delays. The network configures multiple SMTC windows with different timing parameters, and the UE selects the appropriate configuration based on current satellite ephemeris data, making the measurement system flexible rather than fixed

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the timing parameters of SMTC windows and measurement gaps based on satellite propagation delay variations. By adjusting the start time, duration, and periodicity of measurement windows according to real-time satellite position data, the system maintains measurement reliability without requiring complex reconfiguration procedures

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If multiple SMTC windows are configured for different neighbor cells, then measurement precision is improved, but device complexity increases due to per-cell configuration management

Engineering Contradiction:

Improveneighbor cell measurement precisionVSAvoidmeasurement configuration management

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the measurement configuration into cell-specific SMTC windows, where each neighbor cell has its own dedicated timing configuration. This allows precise alignment with each cell's SSB signals while maintaining independent control over measurement parameters for different cells

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The network acts as an intermediary that provides satellite ephemeris data and propagation delay information to the UE. This intermediary role enables the UE to calculate appropriate measurement timing configurations without directly managing complex inter-cell synchronization, simplifying the overall system architecture

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of time

If measurement gaps are aligned with SSB signals, then measurement latency is reduced, but adaptability to satellite mobility deteriorates with fixed configurations

Engineering Contradiction:

Improvemeasurement latencyVSAvoidadaptability to propagation delay changes

Core Design Contradiction:

Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent implements periodic measurement gaps that are synchronized with the periodic transmission of SSB signals from neighbor cells. By aligning measurement opportunities with SSB periodicity, the UE can perform measurements at optimal intervals with minimal latency while the periodic nature allows easy adaptation to satellite mobility through parameter updates

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20250392936A1Measurement configuration in non-terrestrial network (NTN)

Publication Date: 2025.12.25 MEDIATEK SINGAPORE PTE LTD

AI summary

A method includes receiving a measurement configuration from a serving cell of a user equipment (UE) in a non-terrestrial network (NTN) providing mobile communication service based on satellites. The satellites can be low Earth orbiting (LEO) satellites, geostationary Earth orbiting (GEO) satellites, and the like. The measurement configuration indicates a first synchronization signal block (SSB) based measurement timing configuration (SMTC) and a second SMTC. The first SMTC specifies first SMTC windows aligning with SSB signals from the serving cell of the UE. The second SMTC specifies second SMTC windows aligning with SSB signals from a first neighbor cell of the UE. The serving cell is associated with a first flying object, and the first neighbor cell is associated with a second flying object. The UE performs a measurement based on the first SMTC corresponding to the serving cell and the second SMTC corresponding to the first neighbor cell.