The paper proposes a novel approach to achieve monitoring and control of modern substations integrated with renewable-energy resources using advanced computer communication and control technology. The proposed approach is based on hybrid mixing a code division multiple access (CDMA)/interleave division multiple access (IDMA) and optical-CDMA (OCDMA)/optical-IDMA (OIDMA) systems over power-line/optical fiber combining wireless communication technology to realize the utility infrastructure of Smart Grid. Recently, due to the rapid growth on optical fiber/wireless communication technology, it can offer standardized communication technologies for wide-area, metropolitan-area, and local-area networks. When integrating with power grid, communication systems become urgent technologies, which enable the accommodation of distributed renewable-energy generation and act extremely important role in monitoring, operating, controlling, and protecting between renewable-energy generators and power systems. This paper presents hybrid mixing communication systems used in distributed power generation systems (DPGS) such as photovoltaic power-generation systems, wind-turbine power-generation systems, micro-turbine power-generation systems, etc. Finally, this paper outlines some research challenges and opportunities and offers possible solutions of the communication systems for grid integration of renewable-energy resources.