NTN Terminal Timing Control for NCR-Relayed Synchronization

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Solution Overview

Problem

The introduction of a Network Controlled Repeater (NCR) in a Non-Terrestrial Network (NTN) disrupts normal Timing Advance (TA) control due to significant delays, necessitating a solution for suitable synchronization processing.

Innovation Solution

A relay device (NCR) applies a specific time offset for beam control and resource instructions when routing via NTN, and a terminal controls transmission and reception via a relay device for a specific frequency cell, determining TA values based on satellite ephemeris and common parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Timing Advance control is applied in NTN as specified, then synchronization is maintained in direct satellite-UE communication, but TA control does not operate normally when NCR is introduced

Engineering Contradiction:

ImproveTA control operationVSAvoidcompatibility with NCR routing

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic timing adjustment by applying a specific time offset to notification timing based on the routing path (direct NTN vs. NCR-relayed). This dynamic adaptation allows the system to maintain TA control reliability for direct satellite-UE communication while accommodating the different timing characteristics introduced by NCR routing, resolving the contradiction between maintaining original TA control and adapting to NCR integration

Inventive Principle:

Principle #15Dynamics

2Productivity

If NCR is introduced in NTN, then UE power consumption is reduced and throughput is improved, but synchronization processing becomes unsuitable due to routing delays

Engineering Contradiction:

Improvethroughput and power efficiencyVSAvoidsynchronization accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies a predetermined time offset to the timing of notifications (such as beam control and resource instructions) when they are relayed through NCR. This preliminary timing adjustment compensates for the delays introduced by NCR routing before the actual communication occurs, ensuring that synchronization is maintained in advance, thereby allowing the system to utilize NCR's power and throughput benefits while preserving synchronization reliability

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If standard notification timing is used for beam control and resource instructions, then terrestrial network operation is efficient, but NTN routing via NCR experiences timing mismatches

Engineering Contradiction:

Improvenotification processing efficiencyVSAvoidtiming offset delay

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The patent applies different timing treatment to different notification types and routing paths. Specifically, a specific time offset is applied only to notifications that traverse the NCR path in NTN, while direct NTN and terrestrial network notifications maintain their standard timing. This localized timing adjustment preserves the efficiency of standard operations where applicable while correcting timing mismatches only where NCR routing introduces delays

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4712684A1Terminal and wireless communication method

Publication Date: 2026.03.18 NTT DOCOMO INC

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AI summary

A terminal can transmit and receive a radio signal via a relay device connected to a non-terrestrial network, or without the relay device. The terminal controls the transmission and reception of the radio signal via the relay device for a specific frequency cell.