BCSRA: bidirectional-propagation-based crosstalk-avoided spectrum-efficient resource allocation scheme in SDM-EONs

With the development of services such as video streaming and cloud computing, the demand for network capacity and quality of transmission would be gradually increased. Space-division multiplexing elastic optical networks (SDM-EONs) provide a promising approach to support the greater capacities of networks due to their sufficient resources with multi-core transmission existence. Unfortunately, inter-core crosstalk results in significant degradation of spectrum resource utilization and quality of transmission in SDM-EONs. To avoid this dilemma, this paper focuses on the crosstalk mitigation benefit of counter-propagation between the adjacent cores and presents a crosstalk impact fragmentation-aware metric (CIFA) under bidirectional spectrum where the state of spectrum slots is defined as unoccupied (“0”) and occupied (“1” for positive and “−1” for opposite transmissions). In this metric, the crosstalk impact on adjacent cores reflects the utilization of counter-propagation, and the fragmentation is considered to estimate spectrum utilization. Furthermore, benefiting from the presented metric, this paper proposes a bidirectional-propagation-based crosstalk-avoided spectrum-efficient resource allocation (BCSRA) scheme in SDM-EONs, which aims to avoid the crosstalk and fully utilize the spectrum resources in networks. In this scheme, the algorithm assigns the lightpath with the minimum CIFA to the incoming request, which minimizes the impact on future requests. Simulation results show that the proposed BCSRA scheme can effectively reduce the blocking probability and enhance resource utilization while avoiding inter-core crosstalk in SDM-EONs.