Selective HARQ Feedback with Disabled Processes for Long-Delay NTNs
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Solution Overview
Problem
Current LTE and NR technologies face challenges in adapting to non-terrestrial networks (NTNs) due to longer signal propagation delays, which affect Hybrid ARQ (HARQ) operations, leading to inefficiencies and unreliability in data transmissions.
Innovation Solution
Implementing methods for user equipment (UE) and network nodes to manage HARQ processes by enabling or disabling HARQ feedback based on process status and scheduling restrictions, allowing flexible HARQ feedback transmission and reception, even with out-of-order scheduling, to accommodate long delays in NTNs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ feedback is transmitted for all HARQ processes in NTNs, then reliability of data transmissions is improved, but loss of time increases due to long signal propagation delays
Solution Approach 1:
The patent applies partial action by selectively transmitting HARQ feedback only for enabled HARQ processes while omitting feedback for disabled processes. This reduces the total feedback transmission time and processing overhead, directly addressing the time loss issue in NTNs while maintaining reliability for critical data transmissions through the enabled processes.
2Productivity
If multiple HARQ processes are managed simultaneously, then productivity of data transmissions is improved, but device complexity increases due to scheduling restrictions
Solution Approach 1:
The patent segments HARQ processes into enabled and disabled categories, allowing independent management of each group. This segmentation simplifies the scheduling complexity by providing clear rules for feedback transmission (transmit for enabled, omit for disabled) while maintaining the productivity benefits of multiple parallel HARQ processes.
3Device complexity
If HARQ feedback transmission is restricted by out-of-order scheduling, then device complexity is reduced, but loss of time increases due to waiting for in-order feedback
Solution Approach 1:
The patent applies partial action by transmitting HARQ feedback out of order when enabled processes are identified, rather than waiting for all processes to complete in sequence. This selective feedback transmission reduces the waiting time while maintaining manageable device complexity through the enabled/disabled process distinction.
Data Source
AI summary
A method for a UE (1700) to transmit HARQ feedback for data transmissions from a wireless network is disclosed. The UE receives (1530), from the network, a first data message associated with a first HARQ process and a second data message associated with a second HARQ process. At least one of the first and second HARQ processes is disabled. The second data message is received after the first data message. The UE selectively transmits (1560), at a first occasion after the first data message, first HARQ feedback for the first data message based on whether the first HARQ process is enabled or disabled. The UE selectively transmits, at a second occasion after the second data message, second HARQ feedback for the second data message based on the following: whether the second HARQ process is enabled or disabled, an order of the first and second occasions, and an out-of-order scheduling restriction.