A Substitution Network (SN) is a rapidly deployable temporary wireless network that should be dynamically integrated within an existing base network. They back-up the base network inorder to meet temporary network overloaded conditions to keep providing services and to ensure the network connectivity, which could not be achieved by the base network alone. Within this context, in this paper, we propose a solution considering SNs as a means for provisioning backup path for Mobile Network Operators (MNOs) microwave backhaul to overcome network overload due to excessive wireless data traffic. Our approach considers Software Defined Networking (SDN) technology due to its flexibility to integrate diverse future generations of switches as well as its centralized approach for decoupling control-plane and data-plane. Our solution is based on exploring the OpenFlow protocol. Based on our experimental results, we demonstrate the feasibility of our proposal, which allows verifying the effectiveness of adopting SNs based on SDN. Here, our approach is considered in the context of emerging economies, since, from past research, studies have shown that OPEX/CAPEX may not have the same impact in emerging countries as they have in developed countries.