Energy resources, energy conversion processes, and reliable energy delivery are the important issues in the 21st century. Smart grid is an intelligent electricity network aimed at providing interoperability between seven different domains: generation, transmission, distribution, customer, operations, markets, and service provider. This new approach is achieved by integration of power systems, advanced communications and information technology. In this paper, the technologies required for the smart will be studied. Different communication technologies, protocols and standards required for various component of smart grid will be identified.