  We propose an algorithm which produces a randomized strategy reaching optimal
data propagation in wireless sensor networks (WSN).In [6] and [8], an energy
balanced solution is sought using an approximation algorithm. Our algorithm
improves by (a) when an energy-balanced solution does not exist, it still finds
an optimal solution (whereas previous algorithms did not consider this case and
provide no useful solution) (b) instead of being an approximation algorithm, it
finds the exact solution in one pass. We also provide a rigorous proof of the
optimality of our solution.
