Dataplane Based Fast Failover in SDN-Enabled Wide Area Measurement System of Smart Grid

In the wide area measurement system (WAMS) of smart grid, the real-time monitoring and protection applications have stringent requirements for the end-to-end transmission delays between PMUs and PDC, and fast failover is required to ensure the communication performance after link failures. In this work, the software-defined network (SDN) technology is utilized to enable datapath failover upon a link failure with a global view of the communication network. Then, a novel dataplane based fast failover (DFF) mechanism is proposed to directly re-route the data packet in dataplane without interacting with the SDN controller. Based on the mathematical analysis over the WAMS topology features, the proposed DFF optimizes two procedures of failover: backup path construction, and backup path installation. Using the proposed backup path construction algorithms, the 3-approximate and (1+2")-approximate (0 < " < 1) backup paths can be constructed, theoretically guaranteeing the data transmission delays both during and after failover. Using the proposed LinkID-based FF group table installation method, the conflict of forwarding rules between original and backup paths can be eliminated, while the storage cost is also optimized. The simulation results on six IEEE benchmark test power systems show that the proposed DFF mechanism could achieve lower data transmission delays during and after failover compared to the existing control plane based and dataplane based failover mechanisms.