NR-U Contention Window Control for Groupcast and Broadcast Feedback
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Solution Overview
Problem
The existing NR-U system's method for adjusting contention windows based on HARQ feedback is unsuitable for groupcast, multicast, and broadcast scenarios, as it only supports unicast, and there is a need for a solution in SL-U systems to manage contention windows for groupcast, multicast, and broadcast transmissions on unlicensed frequency spectra.
Innovation Solution
A wireless communication method that adjusts contention windows based on feedback information for channels in a reference time unit, considering groupcast, multicast, or broadcast transmission modes, and includes methods to avoid using the same contention window during LBT, reducing interference among multiple devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the NR-U system uses unicast-based HARQ feedback to adjust contention windows, then the method works for single-receiver scenarios, but it cannot handle groupcast, multicast, and broadcast scenarios where multiple receivers provide feedback
Solution Approach 1:
The patent segments the feedback processing by separating ACK feedback and NACK feedback into distinct processing paths. For groupcast/multicast/broadcast scenarios, the system processes feedback from multiple receivers independently and combines the results to determine contention window adjustment, making the system adaptable to different transmission modes while managing complexity through structured processing
Solution Approach 2:
The patent creates a universal feedback processing mechanism that can handle both unicast and groupcast/multicast/broadcast scenarios using the same basic framework. The system determines the transmission mode and applies appropriate feedback processing rules, allowing a single mechanism to serve multiple transmission scenarios
2Object-affected harmful factors
If multiple devices use the same contention window during LBT, then the process is simple, but interference among devices increases
Solution Approach 1:
The patent applies local quality by allowing each device to have its own contention window value tailored to its specific feedback conditions. Devices adjust their contention windows independently based on their individual HARQ feedback experiences, creating differentiated access behavior that reduces interference while maintaining manageable complexity through local adjustments rather than global coordination
Data Source
AI summary
Embodiments of the present disclosure provide a wireless communication method and a first device. The method includes: adjusting, by the first device, a contention window corresponding to each priority of at least one priority, based on feedback information for a first channel transmitted within a reference time unit or a reference time period. A transmission mode of the first channel includes at least one of a groupcast transmission mode, a multicast transmission mode, or a broadcast transmission mode.