In order to adapt the power grid to today's level of electricity consumption, growing investments are made in a smart power grid. The rising power demand curve can be restrained by a smart implementation of the new electrical power grid. The smart grid brings out an additional layer that will interconnect and manage all the generation, transmission and distribution sectors of the power grid. In this paper, we analyze the performance of a smart grid in which the communication layer is implemented using Worldwide-Interoperability for Microwave Access (WiMAX) communication technology. We investigate the performances of the different applications such as metering and pricing, electric car, video surveillance and voice support for workforce. In that, we examine the effect of the impulsive noise over the communication layer. An Orthogonal-Frequency-Division Multiplexing (OFDM) structure using WiMAX physical layer characteristics is considered where the results highlight the effects of the impulsive noise on the bit-error rate, throughput and the overall capacity of the network.