Abstract—Although Smart Grid (SG) is conceived to be a fundamental paradigm shift in the area of power grid, it faces one major challenge which is an efficient and reliable communications structure. In this paper, we identify a possible way in which SG can exploit the use of TVWS for communications using a two-way cognitive radio-based switching procedure. This procedure enable gateways to sense and utilize TVWS channels for communication when they are declared vacant and if occupied by a Primary User (PU), the gateway can alternatively switch transmission over to an unlicensed spectrum band. The optimum sensing time that takes account of the overhead brought about by the sensing process is evaluated. The theoretical analysis are validated through the numerical results.