  Reinforcement learning (RL) is a classical tool to solve network control or
policy optimization problems in unknown environments. The original Q-learning
suffers from performance and complexity challenges across very large networks.
Herein, a novel model-free ensemble reinforcement learning algorithm which
adapts the classical Q-learning is proposed to handle these challenges for
networks which admit Markov decision process (MDP) models. Multiple Q-learning
algorithms are run on multiple, distinct, synthetically created and
structurally related Markovian environments in parallel; the outputs are fused
using an adaptive weighting mechanism based on the Jensen-Shannon divergence
(JSD) to obtain an approximately optimal policy with low complexity. The
theoretical justification of the algorithm, including the convergence of key
statistics and Q-functions are provided. Numerical results across several
network models show that the proposed algorithm can achieve up to 55% less
average policy error with up to 50% less runtime complexity than the
state-of-the-art Q-learning algorithms. Numerical results validate assumptions
made in the theoretical analysis.
