Sidelink Flow Control for Relay User Equipment

The patent segments data flow management by implementing separate buffer queues for different data flows (direct communications and unicast relayed communications). Each buffer queue is independently managed with its own flow control mechanisms, allowing the relay UE to handle multiple communications simultaneously without overwhelming complexity. This segmentation enables scalable management as more communication pairs are added.

The patent implements feedback mechanisms where the relay UE monitors buffer occupancy levels and sends flow control indications back to the source UE. When buffers approach capacity thresholds, the relay UE signals the source UE to reduce or pause data transmission. This closed-loop feedback system enables high data rates while preventing buffer overflow and data loss by dynamically adjusting transmission based on real-time buffer status.

The patent implements preliminary flow control by establishing buffer occupancy thresholds and monitoring mechanisms before overflow occurs. The system proactively manages data flow by detecting buffer status early and triggering flow control actions at optimal moments, rather than reacting after overflow happens. This preliminary action prevents the need for aggressive rate limiting that would cause excessive latency, as flow control is applied smoothly and predictively.

The patent applies local quality by assigning different service priorities and management parameters to different buffer queues based on their specific requirements. Each buffer queue can have customized thresholds, prioritization levels, and flow control parameters tailored to its data flow characteristics. This allows high-priority traffic to receive preferential treatment while low-priority traffic uses remaining resources, achieving quality of service differentiation without uniformly increasing memory requirements for all flows.