P-cycle based protection scheme with cycle multiplexing and capacity balance for multicast service in substation communication network

In order to solve the problem of path protection for multicast services and improve the wavelength utilization ratio in substation communication networks (SCN), a p-cycle based protection scheme with cycle multiplexing and capacity balance (PBCM-CB) is presented in this paper to protect the multicast services under single link/node failure scenario. By analyzing the multicast services in SCN, the classical Prim algorithm is improved to generate optimized multicast light-trees corresponding to multicast requests. Based on this, the heuristic p-cycle generation algorithm is designed to connect the destination nodes of the multicast tree to a cycle to protect the entire tree. Aiming to improve utilization efficiency of the protection resource, the multiplexing conditions of the p-cycles are studied, and by multiplexing the existing p-cycles configured in the network, the wavelength utilization ratio is raised. Besides, in order to decrease the blocking probability (BP) of the network, a capacity balance strategy is adopted to generate the multicast trees and p-cycles. Simulation results demonstrate that the proposed algorithm can significantly reduce the redundancy and blocking probability of SCN compared with the existing flow p-cycle protection schemes.