UE GNSS Measurement Gap Signaling for NTN Uplink Synchronization

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Solution Overview

Problem

IoT devices in NTN networks face challenges in maintaining uplink synchronization due to GNSS position expiration during long transmissions, as they cannot perform GNSS measurements simultaneously with data transmission, leading to inaccurate TA values and synchronization issues.

Innovation Solution

The method involves the UE sending a message to the network with information on GNSS measurement execution, preferences, and mobility data to configure GNSS measurement gaps, allowing the network to determine optimal measurement times and reduce unnecessary measurements, thereby maintaining synchronization and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE performs GNSS measurements during long transmissions to maintain uplink synchronization, then synchronization accuracy is improved, but the UE cannot simultaneously perform data transmission and GNSS measurements

Engineering Contradiction:

Improveuplink synchronizationVSAvoiddata transmission efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent divides the transmission time into different segments: GNSS measurement gaps and data transmission periods. The network configures specific time windows (measurement gaps) where the UE can perform GNSS measurements without interfering with data transmission. This segmentation allows both synchronization maintenance and data transmission to coexist by separating their time resources.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by having the UE perform GNSS measurements before the GNSS position validity expires. The network configures measurement gaps in advance, and the UE uses these pre-arranged time windows to acquire updated positions and calculate TA values before the current position becomes invalid, ensuring continuous synchronization without interrupting ongoing data transmissions.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the network configures frequent GNSS measurement gaps for the UE, then uplink synchronization is maintained, but power consumption increases

Engineering Contradiction:

Improveuplink synchronizationVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of GNSS measurement configuration based on real-time conditions. The UE reports its mobility state (high or low) to the network, which then dynamically adjusts the measurement gap frequency and duration accordingly. This dynamic approach ensures synchronization is maintained when needed while minimizing power consumption during stable conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes key parameters of GNSS measurement configuration including measurement gap duration, frequency, and timing based on UE mobility state and network conditions. The network adjusts these parameters dynamically to match actual synchronization needs, avoiding fixed frequent measurements that would waste power during low-mobility scenarios while maintaining adequate synchronization when mobility requires it.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If the UE performs GNSS measurements continuously, then position accuracy is maintained, but unnecessary measurements waste resources and increase latency

Engineering Contradiction:

ImproveGNSS position accuracyVSAvoidmeasurement latency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent establishes a feedback mechanism where the UE reports its GNSS measurement status, mobility state, and position validity information to the network. Based on this feedback, the network intelligently decides whether to configure new measurement gaps or allow the UE to skip measurements. This feedback loop prevents unnecessary measurements while ensuring accuracy is maintained when truly needed.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies partial action by having the UE perform GNSS measurements only when necessary rather than continuously. The network determines necessity based on mobility state and position validity, configuring measurement gaps selectively. This partial measurement approach avoids excessive measurements that would waste resources and introduce latency, while maintaining sufficient accuracy for synchronization purposes.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP4686251A1Information transmission method, and terminal, network device and storage medium

Publication Date: 2026.01.28 CHINA MOBILE COMM GRP CO LTD

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AI summary

Embodiments of the present disclosure provide information transmission methods, UEs, network devices, and storage media. The method includes: sending, by a UE, a first message to a network, wherein the first message includes at least one of the following pieces of information: no GNSS measurement execution by the UE; skipping next GNSS measurement by the UE; cause(s) for no GNSS measurement execution or skipping next GNSS measurement; preference regarding GNSS measurement gap configuration for the UE; mobility information; requesting the network for GNSS measurement gap configuration; GNSS position validity duration; GNSS measurement successful completion; new GNSS position validity duration or updated GNSS position validity duration; GNSS measurement time duration; identity(es) or index(es) of GNSS measurement execution gap configuration information for GNSS measurement execution; autonomous GNSS measurement execution.