Region-based coordination for distributed resource allocation in sidelink mesh networks

Abstract

Sidelink mesh networking enables multi-hop transmission between user equipments (UEs), which can support emerging Internet-of-things (IoT) applications. In 5G standards, two resource allocation schemes (Mode 1 and Mode 2) are supported for sidelink transmission, but they are unsuitable for sidelink mesh networks. The centralized scheme Mode 1 only works for in-coverage sidelink, which also lacks scalability and adaptability. The distributed scheme Mode 2 overcomes the limitations of Mode 1, but it suffers resource conflict and performance degradation due to its random-access nature. To avoid resource conflict and enhance network performance, coordination among UEs is needed to support distributed resource allocation, yet how to achieve high coordination efficiency and compatibility with 5G standards remains an open problem. To this end, a region-based distributed resource allocation method (RODA) is proposed for sidelink mesh networks. The main idea is that an allocation region contains an allocator, its neighbors as allocatees, and the links between these nodes, where the allocator conducts resource allocation for its inner-region links. Particularly, an allocator determination mechanism is devised to form regions that cover all links in the network. A conflict elimination is developed to avoid resource conflict among regions with interfering links. A resource allocation mechanism is designed to allocate orthogonal and fair resources for inner-region links. A resource notification mechanism is developed to achieve compatibility with 5G standards and coexistence with Mode 2. Extensive simulations validate effectiveness and efficiency of RODA, and also demonstrate its significant throughput and fairness gain over the baseline schemes.