NTN Scheduling Offset Configuration for Uplink Timing
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Solution Overview
Problem
Non-terrestrial networks face challenges in providing efficient access due to increased propagation delay and satellite movement, which affect uplink synchronization and handover processes, especially in high-frequency bands like FR2, where existing parameters are insufficient to support large propagation delays and mobility.
Innovation Solution
The introduction of NTN configuration information, including scheduling offset information indicated by the number of slots based on subcarrier spacing for FR2, is transmitted to user equipment to adjust timing relationships between downlink and uplink channels, enhancing synchronization and mobility by providing a wider range of configuration options.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing parameters are used for terrestrial networks, then device complexity is reduced and ease of operation is improved, but reliability deteriorates due to insufficient support for large propagation delays and satellite mobility
Solution Approach 1:
The patent introduces NTN-specific parameters including scheduling offset indicators (K1, K2, K3) that can be configured in units of slots or sub-slots, allowing flexible adjustment of timing relationships between downlink and uplink channels to compensate for large propagation delays. The uplink synchronization timer is extended to support longer synchronization validity periods suitable for satellite mobility scenarios.
Solution Approach 2:
The patent segments the timing relationship configuration into multiple independent parameters: scheduling offset for PUCCH (K1), scheduling offset for PUSCH (K2), and scheduling offset for SRS (K3). Each parameter can be independently configured based on specific service requirements, allowing fine-grained control over uplink timing without increasing overall system complexity.
2Productivity
If scheduling offset information is indicated by number of slots based on SCS for FR2, then productivity is improved through faster access, but measurement precision deteriorates due to coarser time granularity
Solution Approach 1:
The patent implements dynamic switching between slot-based and sub-slot-based scheduling offset indications based on the subcarrier spacing configuration. For FR2 with larger SCS (e.g., 60kHz), the system can use sub-slot granularity to maintain timing precision while still achieving fast access. The indicator format adapts to the numerology being used, ensuring both speed and precision requirements are met.
3Reliability
If uplink synchronization timer is extended to support larger propagation delays, then reliability is improved, but loss of time increases due to longer synchronization maintenance periods
Solution Approach 1:
The uplink synchronization timer value is configured based on the specific NTN scenario, satellite orbit type, and propagation delay characteristics. Rather than using a fixed extended timer for all cases, the system allows flexible configuration of the timer duration to match the actual synchronization requirements, avoiding unnecessary time consumption while maintaining reliability.
Data Source
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AI summary
According to embodiments, a method performed by a non-terrestrial network (NTN) device for providing a new radio (NR) access may include generating NTN configuration information, and transmitting a message comprising the generated NTN configuration information to a user equipment (UE) via an NTN payload. The NTN configuration information may include scheduling offset information. The scheduling offset information may be applied to a difference between physical downlink control channel (PDCCH) reception and physical uplink control channel (PUCCH) transmission or a difference between PDCCH reception and physical uplink shared channel (PUSCH) transmission. The scheduling offset information may be indicated by a number of slots, based on subcarrier spacing (SCS) for a frequency range (FR) 2 band of the NR.