Low-Latency Relay Selection in NR-V2X Vehicular Communications via Graph Isomorphism Networks with Edge Features
Reliable, low-latency uplink connectivity is crucial for C-V2X networks in dense urban environments. The authors propose an edge-aware Learning-to-Optimise framework for real-time relay selection, which models each V2X snapshot as a directed graph and uses a Graph Isomorp…
Intelligence analysis by Llama

The proposed framework uses a Graph Isomorphism Network with Edge Features to enable edge-level relay activation, achieving tightly bounded inference latency and consistent end-to-end connectivity gains over a 1-hop MILP baseline.
Imagine you're driving in a city and you need to communicate with other vehicles and infrastructure. The authors propose a new way to select the best relay points for this communication, which is like a game of 'connect the dots' but with complex math and computer science. This new method is faster and more efficient than the old way, which is good for things like self-driving cars and smart cities.
Analysis
A Novel Approach to Relay Selection in C-V2X Networks
The authors propose a novel approach to relay selection in C-V2X networks, which is crucial for various applications such as autonomous vehicles and smart cities. The proposed framework uses a Graph Isomorphism Network with Edge Features to enable edge-level relay activation, achieving tightly bounded inference latency and consistent end-to-end connectivity gains over a 1-hop MILP baseline.
Edge-Aware Learning-to-Optimise Framework
The proposed framework models each V2X snapshot as a directed graph, where node features encode vehicle state and traffic demand, and edge features capture radio-link capacity. An offline MILP oracle generates optimal relay configurations that supervise a Graph Isomorphism Network with Edge Features, enabling edge-level relay activation through a single forward pass.
Hybrid GINE-Pruned MILP Strategy
To bridge learning and exact optimisation, the authors propose a hybrid GINE-Pruned MILP (GP-MILP) strategy, in which GINE predictions prune the MILP search space. Experiments on a large-scale dataset generated via an OSM-SUMO-GEMV$^2$ pipeline show that GINE closely matches MILP decisions at the link level and yields consistent end-to-end connectivity gains over a 1-hop MILP baseline.
Implications and Future Work
The proposed framework has the potential to improve the reliability and efficiency of C-V2X networks in dense urban environments. Future work could explore the application of the proposed framework to other wireless communication systems and the development of more efficient algorithms for relay selection.
Key points
- The authors propose a novel approach to relay selection in C-V2X networks using a Graph Isomorphism Network with Edge Features.
- The proposed framework models each V2X snapshot as a directed graph and uses a Graph Isomorphism Network with Edge Features to enable edge-level relay activation.
- The proposed framework achieves tightly bounded inference latency and consistent end-to-end connectivity gains over a 1-hop MILP baseline.
- The authors propose a hybrid GINE-Pruned MILP (GP-MILP) strategy to bridge learning and exact optimisation.
- Experiments on a large-scale dataset generated via an OSM-SUMO-GEMV$^2$ pipeline show that GINE closely matches MILP decisions at the link level and yields consistent end-to-end connectivity gains over a 1-hop MILP baseline.
The proposed framework has the potential to improve the reliability and efficiency of C-V2X networks in dense urban environments, which could lead to the widespread adoption of autonomous vehicles and smart cities.
The proposed framework relies on complex math and computer science, which could make it difficult to implement and scale in real-world scenarios.



