Before revision:  Instead of taking into account three sites and beyond, we propose a novel excitable-wave mean-field approximation . Such approach is also a single-site approximation, but it manages to keep track of the excitable-wave direction of propagation. It shows good agreement with simulations  and accounts for finite-size effects.
After revision:  Instead of taking into account three sites and beyond, we propose a novel excitable-wave mean-field approximation which shows good agreement with simulations and accounts for finite-size effects.