Multipath Relay Scheduling for NR Sidelink Coverage Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current implementations of WTRU-to-network and WTRU-to-WTRU coverage extension in NR-based systems are limited to single-hop SL links and do not adequately support enhanced quality of service requirements, particularly in scenarios with no Uu coverage.
Innovation Solution
Implement methods and apparatuses for scheduling in multipath wireless transmit/receive units (WTRUs) to Network relays, including an SL remote WTRU sending buffer status to a gNB and a relay WTRU, and compensating SR/BSR based on data priority and timing, to enhance coverage extension and QoS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-hop SL links are used for coverage extension, then device complexity is reduced, but connectivity reliability deteriorates in scenarios with no Uu coverage
Solution Approach 1:
The patent segments the single-hop relay link into multiple hops by introducing intermediate relay nodes. Remote WTRUs can communicate through multiple relay WTRUs to reach the network, extending coverage while maintaining connection reliability. The segmentation divides the complex multipath scheduling into manageable per-hop scheduling decisions.
Solution Approach 2:
The patent introduces relay WTRUs as intermediary nodes between remote WTRUs and the gNB. These intermediaries forward data and control information across multiple hops, enabling reliable connectivity in scenarios where direct Uu coverage is unavailable. The intermediary nodes manage resource allocation and scheduling for each hop independently.
2Reliability
If multipath relay scheduling is implemented, then SL connectivity and QoS are improved, but device complexity increases
Solution Approach 1:
The patent segments the multipath scheduling problem into independent per-hop scheduling decisions. Each relay WTRU makes local scheduling decisions based on its own buffer status and resource availability, rather than requiring centralized control of all paths. This reduces overall system complexity while maintaining multiple reliable paths.
Solution Approach 2:
The patent implements preliminary resource selection and buffer status reporting mechanisms. Remote WTRUs report buffer status to relay WTRUs in advance, and resources are selected before data transmission. This preliminary action allows relay nodes to prepare scheduling decisions ahead of time, reducing real-time complexity while ensuring reliable QoS.
3Measurement precision
If buffer status reporting is enhanced for mode 2 transmissions, then resource allocation precision is improved, but signaling overhead increases
Solution Approach 1:
The patent implements local quality buffer status reporting where each relay WTRU reports buffer status specific to its own logical channels and received data. Rather than centralized detailed reporting from all nodes, each node provides locally relevant buffer information to enable precise resource allocation at each hop while minimizing overall signaling overhead.
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Methods, apparatuses, and procedures for scheduling of multipath relays in wireless communications are disclosed. For example, a method implemented in a wireless transmit/receive unit (WTRU) includes determining that data to be transmitted has a priority greater than a priority threshold; determining timing information associated with a selected set of resources for transmitting the data, and the timing information indicates a time resource for transmitting the data is less than a time resource threshold; transmitting, to a network entity, a first message including information indicating a buffer status associated with the data and the timing information associated with the selected set of resources; and transmitting, to a relay WTRU on a sidelink transmission, a second message including information indicating the buffer status.