Logical optical line terminal placement optimization in the elastic lambda aggregation network with optical distribution network constraints

The elastic lambda aggregation network (EλAN) has been presented as an access/aggregation integrated network that can accommodate multiple network services. In the EλAN, optical line terminals (OLTs) become programmable and configure logical OLTs (L-OLTs) to support network services that have different protocols and quality of service requirements. To achieve the flexible utilization of network resources and improve energy efficiency, L-OLTs are migrated between programmable OLTs like virtual machines. In this paper, an integer linear programming (ILP) model of the L-OLT placement optimization problem with optical distribution network constraints is presented. Based on this ILP model, the communication suspension time that occurs with L-OLT migration is investigated. We discuss the modification of the L-OLT migration sequence to reduce the communication suspension time. The impact of the modification on the energy saving effect of L-OLT placement optimization is evaluated in this paper.