“…If problem (A) is a stochastic convex programming problem, (i.e., U s,i (P s,i ), ∀i, ∀s is a concave function), there is no duality gap between it and its dual. Hence, we can obtain its optimal power scheduling by solving its dual [13]. However, since problem (A) may not be a stochastic convex programming problem, typically, we can guarantee neither optimality, nor feasibility (in terms of minimum performance constraints 4 ) of the solution that is obtained by solving the dual.…”