Unsupervised Graph-based Learning Method for Sub-band Allocation in 6G Subnetworks
Daniel Abode, Ramoni Adeogun, Lou Salaün, Renato Abreu, Thomas Jacobsen, Gilberto Berardinelli
TL;DR
This work tackles sub-band allocation in dense 6G subnetworks by modeling interference as a graph and solving a graph-coloring-like problem with an unsupervised GGNN approach. A interference graph is constructed by linking each subnetwork to its $K-1$ strongest interferers, and a Potts-model-inspired loss $\\ ext{\\Psi}(\\hat{\\theta})=\\sum_{(n,m)\\in \\mathcal{E}} \\hat{\\theta}_n^T \\hat{\\theta}_m$ guides the learning without ground-truth labels. The GGNN learns to classify nodes into sub-band choices, providing results competitive with centralized greedy coloring while reducing signaling and runtime; it also shows robustness to density and channel-model variations and can operate in centralized or decentralized modes. This approach offers scalable, data-driven interference coordination suitable for large-scale subnetworks in dynamic 6G environments, with potential extensions to traffic and mobility scenarios.
Abstract
In this paper, we present an unsupervised approach for frequency sub-band allocation in wireless networks using graph-based learning. We consider a dense deployment of subnetworks in the factory environment with a limited number of sub-bands which must be optimally allocated to coordinate inter-subnetwork interference. We model the subnetwork deployment as a conflict graph and propose an unsupervised learning approach inspired by the graph colouring heuristic and the Potts model to optimize the sub-band allocation using graph neural networks. The numerical evaluation shows that the proposed method achieves close performance to the centralized greedy colouring sub-band allocation heuristic with lower computational time complexity. In addition, it incurs reduced signalling overhead compared to iterative optimization heuristics that require all the mutual interfering channel information. We further demonstrate that the method is robust to different network settings.
