Can NR-V2X Sidelink support A2A links?

2026-03-24

AI Summary

This study investigates the applicability of the NR-V2X sidelink autonomous resource allocation mechanism specified in 3GPP Release 18 to kilometer-scale air-to-air (A2A) direct communications. Addressing the impact of propagation delay on synchronization and resource scheduling over long-distance links, the work presents the first systematic evaluation of the feasibility of existing standards in A2A scenarios. By integrating propagation modeling with link budget analysis, the study delineates the performance boundaries of the current framework. Findings indicate that Release 18 specifications can be directly applied for distances up to 42.4 km; beyond this threshold, adjustments to transmission timing are required to compensate for propagation delay. This research provides critical distance thresholds and concrete recommendations to inform future standardization efforts for A2A communications.

Technology Category

• Planning, Routing, and Scheduling: Applications
• Multiagent Systems: Agent Communication
• Application Domains: Mobility, Driving & Flight

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

In the context of 5G, 3GPP introduced New Radio vehicle to everything (NR-V2X) for direct vehicle-to-vehicle communication. However, starting from Release 18 the focus of the standard has been expanded from vehicles to any device and use case that can benefit from direct communication. In 3GPP terminology, the standard is now referred to simply as Sidelink communication. This standard allows direct communication between devices based on synchronous resource scheduling. Users can rely on controlled scheduling when in network coverage or, in the absence of coverage, autonomously select resources for transmission via a distributed resource allocation mechanism. Focusing on the autonomous resource allocation, this paper investigates the possibility of applying Release 18 Sidelink communication to Air-to-Air (A2A) links between airborne entities. The paper outlines the main challenges and required modifications to adapt the current standard for longer links in the order of kilometres. The analysis identifies the propagation delay as a critical limitation. Communications at distances over 42.4 km require a restriction of the user's transmitting opportunities. However, sidelink communication remains feasible for distances below this threshold without modifications to the standard.

Problem

• NR-V2X
• Sidelink
• Air-to-Air
• propagation delay
• autonomous resource allocation

Innovation

• NR-V2X
• Sidelink
• Air-to-Air communication
• autonomous resource allocation
• propagation delay