Multicast Feedback Switching for NR Resource Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing ACK/NACK feedback for multicast services due to the complexity of receiving and managing feedback from a large number of user equipment devices, leading to issues such as misinterpretation of scheduling grants and inability to estimate UE-specific channel state information.
Innovation Solution
The implementation of a method that allows flexible switching between a common NACK-only feedback mode and a UE-specific ACK/NACK feedback mode, where each UE in a multicast group is configured with separate resource configurations for NACK-only and ACK/NACK feedbacks, allowing the network to dynamically adjust feedback modes based on channel conditions and network load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a common NACK-only feedback mode is used for all UEs in multicast group, then feedback resource usage is reduced and overhead is minimized, but the network cannot estimate UE-specific channel state information and may misinterpret scheduling grants
Solution Approach 1:
The patent implements dynamic feedback mode switching that allows the network to transition between common NACK-only feedback mode and UE-specific ACK/NACK feedback mode based on current channel conditions and network load. This dynamic adaptation enables the system to use resource-efficient common feedback when conditions permit, while switching to UE-specific feedback when accurate CSI estimation is required, thus resolving the contradiction between resource usage and information quality.
Solution Approach 2:
The patent changes the feedback mode parameter based on channel conditions and network state. By monitoring channel quality indicators and network load, the system adjusts the feedback configuration parameter to select between common and UE-specific feedback modes, allowing optimal balance between resource efficiency and information accuracy for different operating conditions.
2Measurement precision
If UE-specific ACK/NACK feedback mode is used for all UEs, then the network can accurately estimate UE-specific channel state information, but feedback resource usage and overhead increase significantly
Solution Approach 1:
The system dynamically adjusts feedback mode based on whether high-precision CSI estimation is currently needed. During phases requiring accurate channel state information (such as initial connection or poor channel conditions), the system activates UE-specific feedback mode. During stable phases with good channel conditions, it switches to common feedback mode, thus achieving measurement precision only when necessary and reducing overall resource consumption.
Solution Approach 2:
The feedback configuration parameter is changed based on network conditions and requirements. When the network determines that UE-specific CSI estimation is critical, it sets the feedback mode parameter to enable UE-specific feedback. When resource efficiency is prioritized and channel conditions are stable, the parameter is changed to common feedback mode, optimizing the trade-off between measurement precision and resource quantity.
3Device complexity
If common resource pools are used for feedback transmission, then resource overhead is reduced, but the system cannot differentiate between individual UE feedback and may misinterpret scheduling grants
Solution Approach 1:
The patent implements dynamic switching between common feedback resources and UE-specific feedback resources. When using common resources, the system employs specific interpretation rules for NACK-only feedback to maintain reliability. When switching to UE-specific resources, the system can accurately differentiate individual UE feedback. This dynamic resource allocation maintains reliability while managing complexity appropriately for different operational scenarios.
Solution Approach 2:
The patent applies different feedback interpretation rules based on the feedback mode. For common NACK-only feedback resources, the system uses simplified interpretation (NACK indicates missed grant). For UE-specific ACK/NACK resources, the system uses detailed interpretation that can differentiate individual UE responses. This local quality adaptation ensures reliable interpretation appropriate to each resource type while managing overall system complexity.
4Reliability
If the network switches between common and UE-specific feedback modes, then multicast service reliability is improved, but the switching complexity and configuration overhead increase
Solution Approach 1:
The patent uses feedback mechanisms where UEs report their reception status and channel conditions to the network. Based on this feedback, the network intelligently determines when switching between common and UE-specific feedback modes would improve reliability. This feedback-driven switching reduces arbitrary complexity by base mode transitions on actual service requirements and channel conditions, maintaining reliability while minimizing unnecessary switching complexity.
Solution Approach 2:
The network performs preliminary assessment of channel conditions and service requirements before switching feedback modes. By evaluating current multicast service reliability needs and channel state before transitioning between common and UE-specific feedback modes, the system avoids premature or unnecessary switching, thus improving reliability while reducing switching complexity and configuration overhead.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Wireless communications systems and methods related to acknowledgement/negative-acknowledgement (ACK/NACK) feedback operations for multicast communications are provided. A first user equipment (UE) receives, from a base station (BS), a multicast feedback configuration indicating a first resource configuration for a negative-acknowledgement (NACK) feedback mode; and a second resource configuration for an acknowledgement/negative-acknowledgement (ACK/NACK) feedback mode. The first UE receives, from the BS, a first multicast communication. The first UE transmits, to the BS, a NACK feedback for the first multicast communication based on the first resource configuration. The first UE receives, from the BS, a second multicast communication. The first UE transmits, to the BS, an ACK feedback or a NACK feedback for the second multicast communication based on the second resource configuration.