Scheduling Offset Update for Non-Terrestrial Network Timing
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Solution Overview
Problem
In non-terrestrial networks, the random characteristics of channels and high altitudes of satellites lead to ineffective handover procedures based on reference signal received power (RSRP), making it difficult to precisely configure cell coverage and determine uplink transmission timing.
Innovation Solution
A method for updating and signaling scheduling offsets in a non-terrestrial network, where a satellite periodically transmits scheduling offsets to user equipment (UE), adjusting update periodicity based on preset conditions such as elevation angle and distance, to improve uplink transmission timing and handover performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RSRP-based handover procedure is used in NTN, then handover can be performed, but it is ineffective due to random channel characteristics and small RSRP difference in wide coverage area
Solution Approach 1:
The patent changes the measurement parameter from RSRP (reference signal received power) to timing advance (TA) based measurements. By using timing advance values which reflect the actual propagation delay and satellite position, the handover decision can be made more accurately in NTN environments where RSRP differences are minimal due to wide coverage areas.
Solution Approach 2:
The patent replaces the traditional RSRP-based measurement mechanism with a timing advance-based measurement mechanism. This substitution allows the system to use timing information, which has better differentiation capability in NTN, instead of power-based measurements that become less effective in wide coverage scenarios.
2Manufacturing precision
If cell coverage is configured based on RSRP and RSRQ, then coverage can be defined, but it is difficult to precisely configure due to random channel characteristics
Solution Approach 1:
The patent changes the parameters used for cell coverage configuration from RSRP and RSRQ to timing advance-based parameters. By using timing advance values that directly reflect the propagation characteristics and satellite-UE geometry, the system can more precisely define and configure cell coverage boundaries in NTN environments.
3Loss of information
If scheduling offset is not updated dynamically, then signaling overhead is reduced, but uplink transmission timing accuracy deteriorates due to changing satellite-UE relationship
Solution Approach 1:
The patent implements periodic updates of the scheduling offset (K2) parameter based on timing advance changes. Instead of continuous updates, the system periodically refreshes the scheduling offset information when timing advance variations exceed a threshold or after a certain time interval, balancing signaling overhead with timing accuracy requirements.
Solution Approach 2:
The patent makes the scheduling offset dynamic by updating it based on changing timing advance values. The scheduling offset is adjusted according to the satellite-UE relative motion and propagation delay changes, ensuring that uplink transmission timing remains accurate despite the dynamic NTN environment.
Data Source
AI summary
A method and a device for timing control in a non-terrestrial network are provided. The method includes: transmitting, to a UE, first system information including a first scheduling offset; determining a first update period of the first scheduling offset; transmitting, to the UE, a first message including information about the first update period; and transmitting, to the UE, a second message including information about a scheduling offset updated according to the first update period.