Base Station HARQ Feedback Post-Indicator for URLLC Pre-emption
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Solution Overview
Problem
Current mobile telecommunications systems, particularly in the transition to 5G, face challenges in efficiently managing HARQ feedback and retransmissions due to the pre-emption of resources by ultra-reliable and low-latency communications (URLLC) on existing LTE and LTE-A systems, which can corrupt enhanced mobile broadband (eMBB) transmissions and disrupt the HARQ timeline.
Innovation Solution
The implementation of a base station and user equipment circuitry that dynamically overrides the HARQ feedback schedule by using a post-indicator to postpone the HARQ ACK/NACK response, allowing sufficient time for the user equipment to process retransmitted data, and reschedules resources to ensure accurate HARQ feedback transmission after the completion of data processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If URLLC transmissions are allowed to pre-empt eMBB resources for low-latency communication, then URLLC reliability and latency are improved, but eMBB transmission integrity is corrupted and HARQ feedback timing is disrupted
Solution Approach 1:
The patent introduces a post-indicator as an intermediary signal that mediates between URLLC pre-emption and eMBB HARQ feedback. The post-indicator is transmitted after the URLLC transmission to indicate whether eMBB resources were pre-empted, allowing the UE to adjust its HARQ feedback timing accordingly without corrupting the eMBB transmission integrity
Solution Approach 2:
The patent implements dynamic HARQ feedback timing adjustment based on URLLC pre-emption conditions. The HARQ feedback timeline is made flexible rather than fixed, allowing the UE to postpone its ACK/NACK transmission when pre-emption is detected, thus adapting the system to handle both URLLC low-latency requirements and eMBB reliability requirements
2Loss of time
If HARQ feedback is transmitted according to the original schedule after URLLC pre-emption, then HARQ feedback timing is maintained, but data processing is incomplete and feedback accuracy is compromised
Solution Approach 1:
The patent makes the HARQ feedback timeline dynamic by allowing postponement of the ACK/NACK transmission when URLLC pre-emption occurs. The UE can adjust its feedback timing based on whether pre-emption was detected, ensuring that feedback is transmitted only after complete data processing while maintaining timing synchronization through the post-indicator mechanism
3Reliability
If eMBB transmissions are protected from URLLC pre-emption to maintain transmission integrity, then eMBB reliability is improved, but URLLC low-latency communication capability is degraded
Solution Approach 1:
The patent applies local quality by protecting only the specific eMBB resources that are actually pre-empted by URLLC, rather than protecting all eMBB resources globally. The post-indicator provides localized information about which resources were affected, allowing selective adjustment of HARQ feedback timing only for the impacted transmissions, thus minimizing impact on URLLC performance
Data Source
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AI summary
A base station for a mobile telecommunications system has circuitry which is configured to communicate with at least one user equipment. The circuitry is further configured to: transmit a short data transmission within the time scheduled for a long data transmission; and schedule, based on the transmission of the short data, a HARQ ACK/NACK response relating to at least a part of the long data transmission.