Shortest Path First to Optimize the Optical Multicast Routing Cost and Wavelength Consumption for WDM Network

Abstract

Due to optical node light splitting constraint, the minimal cost optical multicast routing tree is an important issue solved normally by bypassing the nodes which violate splitting capability with a good few route cost or consuming more wavelength channel. The method of shortest path first to re-route the contending optical packet to destination nodes is presented for optimization the re-route cost and wavelength consumption in the paper. The minimal cost multicast tree is used first to search the tree overlaying the source node and all destination. Then, the shortest path first is designed to bypass the nodes on the tree which violate the light-splitting constraint with the minimal re-route cost increment for the optical multicast. According to the wavelength consumption cost factor, the wavelength consumption cost increment is calculated if the new wavelength channel is assigned for the tree nodes violating the light-splitting. Lastly, by comparing re-routing path multicast cost increment with the new assignment wavelength consumption cost increment, a minimal cost multicast routing is determined for the optical network with some nodes light splitting constraint. Furthermore, according to the actual network available wavelength scarcity, the wavelength consumption cost factor can be increased. Simulation results show that the proposed algorithm can achieve the optimal low-cost multicast tree and few wavelengths consumption also.