Decentralized Learning Strategies for Estimation Error Minimization with Graph Neural Networks
Xingran Chen, Navid NaderiAlizadeh, Alejandro Ribeiro, Shirin Saeedi Bidokhti
TL;DR
This work tackles real-time sampling and estimation in dynamic, multi-hop wireless networks by bridging graph neural networks with multi-agent reinforcement learning. The proposed graphical MARL framework combines a graphical actor-critic pair with a graph-based action distribution, enabling decentralized decisions that minimize the time-average estimation error. A key theoretical contribution is the transferability analysis, showing policies trained on structurally similar graphs generalize to larger networks via graphon-based arguments and WRNN-GRNN correspondence. Empirical results demonstrate superior performance over baselines, effective transfer to larger graphs, robustness to non-stationarity through recurrence and centralized training with decentralized execution, and notable gains in both synthetic and real network topologies. This work advances scalable, transferable decentralized learning for real-time estimation in dynamic wireless environments.
Abstract
We address real-time sampling and estimation of autoregressive Markovian sources in dynamic yet structurally similar multi-hop wireless networks. Each node caches samples from others and communicates over wireless collision channels, aiming to minimize time-average estimation error via decentralized policies. Due to the high dimensionality of action spaces and complexity of network topologies, deriving optimal policies analytically is intractable. To address this, we propose a graphical multi-agent reinforcement learning framework for policy optimization. Theoretically, we demonstrate that our proposed policies are transferable, allowing a policy trained on one graph to be effectively applied to structurally similar graphs. Numerical experiments demonstrate that (i) our proposed policy outperforms state-of-the-art baselines; (ii) the trained policies are transferable to larger networks, with performance gains increasing with the number of agents; (iii) the graphical training procedure withstands non-stationarity, even when using independent learning techniques; and (iv) recurrence is pivotal in both independent learning and centralized training and decentralized execution, and improves the resilience to non-stationarity.
