Network Virtualization for Smart Grid Communications

Information exchange is critical in smart grid for system control and management. Optical fibers are widely used in transmission grid and substations to provide high-capacity and high-reliability communications. However, due to high cost and inflexibility, optical fibers are not suitable for information transmission in distribution grid. Wireless mesh network (WMN) and power line communication (PLC) network are more appropriate for distribution grid communications. Nonetheless, both WMN and PLC technologies tend to suffer from bit error and packet loss due to interference and attenuation. It is extremely difficult to provide real-time services with low delay and high reliability in both of them. Network virtualization (NV) is a promising technology to support customized end-to-end performance of various services. In this paper, an NV-based framework is proposed for smart grid communications. In the framework, real-time services are supported by virtual networks (VNs) that are mapped to two physical networks simultaneously, i.e., WMN and PLC network. The WMN for NV is designed to adopt orthogonal frequency division multiple access as the multiple access scheme. In this way, different VNs are allocated distinct subcarriers. Concurrent transmissions in multiple subcarriers bring the benefit of additional diversity. The enhanced transmission diversity through the two networks and the allocated subcarriers contributes to the reliability guarantee of the real-time services. Since the VN mapping and subcarrier assignment problem is nondeterministic polynomial-time hard, a heuristic solution is developed to solve the problem efficiently and effectively. Simulation results reveal the effectiveness of our proposed framework.