Multicast HARQ Feedback Fallback Under RNTI-Specific Conditions
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Solution Overview
Problem
Existing wireless communication standards do not adequately address the handling of fallback operations for semi-static hybrid automatic repeat request (HARQ) feedback codebooks in multicast scenarios, leading to inconsistent UE behavior and incorrect network entity interpretation due to varying RNTI configurations and feedback types.
Innovation Solution
Implementing a fallback HARQ feedback indication mechanism for UEs based on radio network temporary identifiers (RNTIs) and feedback configurations, allowing UEs to transmit fallback HARQ feedback indications instead of semi-static HARQ feedback codebooks, synchronized with RNTI-specific conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a semi-static HARQ feedback codebook is used for multicast, then feedback coverage is improved, but UE behavior becomes inconsistent due to varying RNTI configurations
Solution Approach 1:
The patent changes the parameter of feedback transmission by introducing a fallback mechanism that switches between semi-static HARQ feedback codebook and fallback HARQ feedback indication based on RNTI-specific conditions. This allows the system to adapt the feedback parameter (codebook vs. indication) according to the specific RNTI configuration, resolving the inconsistency in UE behavior while maintaining feedback coverage.
Solution Approach 2:
The patent introduces dynamic selection between two feedback mechanisms (semi-static codebook and fallback indication) based on RNTI configurations. The UE dynamically determines which feedback type to use by checking RNTI-specific conditions, making the feedback system flexible and consistent across different RNTI scenarios rather than rigidly using semi-static codebook for all cases.
2Loss of energy
If fallback HARQ feedback indication is transmitted, then resource consumption is reduced, but feedback interpretation accuracy may deteriorate without proper synchronization
Solution Approach 1:
The patent implements a feedback mechanism where the network entity provides RNTI-specific feedback configuration that tells the UE when to use fallback HARQ feedback indication instead of semi-static codebook. This feedback loop ensures that the UE and network entity are synchronized about which feedback type to use, maintaining interpretation accuracy while enabling resource savings when fallback indication is appropriate.
Solution Approach 2:
The RNTI-specific feedback configuration acts as an intermediary that mediates between the UE's feedback transmission and the network entity's interpretation. This intermediary provides the synchronization information needed to ensure that when fallback indication is used, the network entity can correctly interpret it, preventing loss of accuracy while maintaining resource efficiency.
3Measurement precision
If RNTI-specific feedback configuration is implemented, then feedback interpretation accuracy is improved, but system complexity increases
Solution Approach 1:
The patent segments the feedback configuration into RNTI-specific configurations, where each RNTI has its own feedback type indication. This segmentation allows the system to manage complexity by organizing configuration data in a structured, per-RNTI manner rather than requiring a single complex configuration for all UEs, making the system more manageable while improving interpretation accuracy.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network entity, configuration information associated with a semi-static hybrid automatic repeat request (HARQ) feedback codebook for multicast messages. The UE may receive, from the network entity, a physical downlink control channel (PDCCH) message, associated with a radio network temporary identifier (RNTI), scheduling one or more multicast physical downlink shared channel (PDSCH) messages. The UE may transmit, to the network entity, one or more fallback HARQ feedback indications, associated with the one or more multicast PDSCH messages, in lieu of transmitting the semi-static HARQ feedback codebook, in accordance with the configuration information and associated with at least one of the RNTI or a feedback configuration associated with the RNTI. Numerous other aspects are provided.