Fragmentation-aware Coordinated Virtual Optical Network Embedding Algorithm Over Elastic Optical Networks

Network virtualization has become a key solution for meeting the exploding needs of users and applications because of the growing demand for high performance-applications and cloud network services. Virtual optical network embedding (VONE) over elastic optical networks (EONS) is a fundamental technology to realize network virtualization. The VONE over EON is suffering from poor spectrum utilization due to the existence of non-aligned and non-contiguous slots, which is known as spectrum fragmentation. The goal of our coordinated algorithm based on the exact fit policy is to minimize the average number of used slots and shorten the length of the physical lightpath serves a virtual optical links. Results show not only our algorithm achieves the closest results to the ILP method, but also it improves the average number of used slots in a five-node topology by 21.9%. In addition, in a large topology, it significantly reduces the length of the lightpaths that serve virtual optical links, improving spectrum utilization and reducing the bandwidth blocking probability