HARQ Mini-Slot Scheduling for Low Latency URLLC
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Solution Overview
Problem
Current Hybrid Automatic Repeat Request (HARQ) techniques in wireless communication systems face challenges in reducing latency while maintaining high reliability, especially for Ultra Reliable Low Latency Communications (URLLCs) due to increased latency from error detection and correction processes.
Innovation Solution
Scheduling HARQ transmissions and feedback messages in mini-slots within a Physical Resource Block (PRB), allowing for self-contained acknowledgments and adaptive mini-slot sizing based on service types, fading conditions, and device locations to optimize latency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ error detection and correction processes are implemented, then reliability is improved, but latency increases
Solution Approach 1:
The patent segments the communication resource into mini-slots of varying sizes rather than using fixed-size slots. This allows the system to divide the transmission time into smaller, more flexible units that can be optimized for different service requirements, thereby reducing the time required for error detection and correction processes while maintaining reliability.
Solution Approach 2:
The patent implements dynamic mini-slot sizing where the size of each mini-slot is adapted based on service type, fading conditions, and device location. This dynamic adjustment allows the system to optimize the balance between reliability and latency for different communication scenarios, reducing unnecessary processing time when full error correction is not required.
2Ease of operation
If fixed-size slots are used for HARQ transmissions, then scheduling simplicity is maintained, but latency cannot be optimized for different service types
Solution Approach 1:
The patent transitions from fixed-size slots to dynamic mini-slot structures where the size can be adjusted based on service requirements, fading conditions, and device location. This maintains scheduling simplicity through standardized procedures while enabling latency optimization by adapting slot sizes to specific communication needs.
Solution Approach 2:
The patent changes the temporal parameter of resource allocation by introducing variable mini-slot sizes. This allows the system to optimize latency for different service types (e.g., URLLC vs. eMBB) while maintaining ease of operation through systematic scheduling rules and base station control.
3Quantity of substance
If larger slots are used for HARQ transmissions, then more data can be transmitted, but latency increases
Solution Approach 1:
The patent segments large data transmissions into multiple smaller mini-slots rather than transmitting everything in a single large slot. This allows for parallel processing and faster acknowledgment cycles, reducing overall latency while maintaining the ability to transmit large volumes of data through aggregated mini-slot transmissions.
Solution Approach 2:
The patent implements periodic HARQ feedback mechanisms within the mini-slot structure, allowing for iterative transmission and acknowledgment cycles. This periodic action enables the system to transmit larger data volumes by breaking them into manageable chunks with intermediate feedback points, reducing total latency compared to waiting for complete transmission.
Data Source
AI summary
Systems, methods, and devices can be utilized to schedule at least one Hybrid Automatic Repeat Request (HARQ) transmission and at least one HARQ feedback message in the same Physical Resource Block (PRB). A HARQ transmission can be scheduled in a mini-slot of the PRB. Accordingly, latencies associated with transmitting and receiving the PRB can be reduced, while the high reliability of HARQ can be retained. Implementations can be applied to 5G technologies such as Ultra Reliable Low Latency Communications (URLLCs) and enhanced Mobile BroadBand (eMBB), as well as other low-latency communications. A method can include detecting a fading condition of a device; scheduling, in one or more mini-slots of a PRB, a HARQ transmission based at least in part on the fading condition; and transmitting, to the device, the HARQ transmission in the one or more mini-slots of the PRB.