HARQ-ACK Feedback Timer for Uplink Retransmission Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The current LTE system lacks a concrete scheme for explicit HARQ-ACK feedback to distinguish between discontinuous transmission (DTX) and negative acknowledgement (NACK), which hinders the reliability and efficiency of uplink data transmission in new radio (NR) Rel-16.
Innovation Solution
A method for controlling data retransmission is introduced, where a timer is started for data transmission, and retransmission occurs if no HARQ-ACK feedback is received or if HARQ-ACK feedback is received before the timer expires, utilizing HARQ buffer flushing and resource allocation for retransmission based on timer and grant feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If explicit HARQ-ACK feedback is implemented to distinguish DTX from NACK, then uplink transmission reliability is improved, but device complexity increases due to the need for timer-based retransmission control mechanisms
Solution Approach 1:
The patent implements explicit HARQ-ACK feedback mechanisms where the network device sends HARQ-ACK feedback to the terminal device to indicate whether uplink data was successfully received. This feedback system distinguishes between DTX (no feedback received) and NACK (feedback received indicating failure), enabling the terminal device to make informed retransmission decisions and thereby improving uplink transmission reliability.
Solution Approach 2:
The patent employs timer-based mechanisms where the terminal device starts a timer before expecting HARQ-ACK feedback. If the timer expires before receiving feedback, the terminal device can proactively determine DTX condition and trigger retransmission without waiting for network indication, thus improving reliability while managing complexity through predetermined timing rules.
2Reliability
If data retransmission is triggered based on timer expiration and HARQ-ACK feedback, then data transmission reliability is improved, but transmission delay increases due to additional retransmission procedures
Solution Approach 1:
The patent implements dynamic retransmission control where the terminal device adapts its retransmission behavior based on real-time conditions. The device monitors whether HARQ-ACK feedback is received before timer expiration and dynamically decides whether to retransmit data. This dynamic approach ensures reliable delivery while minimizing unnecessary retransmissions that would increase delay.
Solution Approach 2:
The terminal device autonomously manages its own retransmission process by monitoring timer expiration and HARQ-ACK feedback reception. The device can independently determine when retransmission is necessary without continuous network intervention, thereby improving reliability while reducing overall transmission delay through self-directed error correction.
3Productivity
If HARQ buffer is flushed upon receiving HARQ-ACK feedback before timer expiration, then resource efficiency is improved, but risk of data loss increases if feedback is mistakenly received
Solution Approach 1:
The patent replaces manual or complex judgment logic with a standardized timer-based mechanism. The terminal device compares the current time against the timer expiration time to determine whether to flush the HARQ buffer. This mechanical time-comparison approach reduces complexity and minimizes erroneous decisions compared to more complex judgment algorithms, thereby improving resource efficiency while maintaining data reliability.
Data Source
AI summary
A method for controlling data retransmission is provided. Data is transmitted to network device and a timer is started. The data is retransmitted after the timer expires if a HARQ-ACK feedback corresponding to the data is not received before the timer expires. Or the data is retransmitted if a HARQ-NACK feedback corresponding to the data is received from the network device before the timer expires.