NTN HARQ Process Switching to Cut Delay and Buffer Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of existing HARQ solutions in LTE or NR systems for NTN communication leads to increased communication delay and buffer pressure at the receive end.
Innovation Solution
A method and apparatus that adapt HARQ processes to NTN by allowing some processes to operate without HARQ manner, utilizing unused bits in DCI to indicate process numbers and transmission manners, enabling dynamic HARQ mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing HARQ solution is applied to NTN communication, then data transmission reliability is improved, but communication delay increases and buffer pressure at receive end increases
Solution Approach 1:
The patent segments HARQ processes into two types: first HARQ processes that use traditional HARQ with feedback, and second HARQ processes that use new HARQ without feedback. This segmentation allows selective application of HARQ mechanisms based on traffic requirements, reducing unnecessary feedback delays for certain data transmissions while maintaining reliability through appropriate process selection.
Solution Approach 2:
The patent introduces dynamic HARQ process management where the network can dynamically configure and switch between different HARQ process types based on channel conditions, traffic characteristics, and quality of service requirements. This dynamic adaptation enables the system to optimize between reliability and delay by adjusting HARQ process behavior in real-time.
2Reliability
If existing HARQ solution is applied to NTN communication, then data transmission reliability is improved, but buffer pressure at receive end increases
Solution Approach 1:
By dividing HARQ processes into feedback-based and feedback-free types, the patent reduces the need for extensive buffering in feedback-free processes. The receive end only needs to buffer data for first HARQ processes that require feedback, while second HARQ processes can be processed more immediately, thereby reducing overall buffer pressure.
Solution Approach 2:
The patent extracts the feedback mechanism from certain HARQ processes (second HARQ processes), removing the requirement for receive end buffering and feedback generation for those specific data transmissions. This extraction reduces buffer pressure while maintaining adequate reliability through the remaining feedback-based processes.
3Productivity
If HARQ process number is increased to improve throughput, then data transmission throughput is improved, but device complexity increases
Solution Approach 1:
The patent implements dynamic HARQ process configuration where the network can flexibly activate and deactivate different HARQ processes based on current traffic demands and channel conditions. This dynamic management allows the system to achieve high throughput when needed while reducing complexity by deactivating unnecessary processes during low-demand periods.
Solution Approach 2:
The patent changes the operational parameters of HARQ processes by introducing a feedback flag that determines whether each process uses traditional feedback-based HARQ or new feedback-free HARQ. This parameter change allows the same HARQ process infrastructure to support multiple operational modes, improving throughput without proportionally increasing complexity.
Data Source
AI summary
Example non-terrestrial network (NTN)-based data transmission methods and apparatus are described. In one example method, a first hybrid automatic repeat request (HARQ) process for data transmission does not use a HARQ transmission manner, and an unused bit in DCI may be multiplexed. The DCI includes a first part of bits indicating a process number of the first HARQ process. Another part of bits of the DCI may indicate the process number or another parameter. The terminal device perform data processing by using the DCI and output processed data, that is, perform data transmission.