Traffic grooming policies under switching constraints in next-generation transport networks

Abstract—Network planning evolves alongwith the developments in optical transport technology. In the current ecosystem, network elements are required to be increasingly flexible in order to respond to changing requirements more rapidly. Transmission modules such as the sliceable bandwidth- variable transponder (SBVT) are a step forward in this direction, enabling us to adapt line-rates at the same time that multi-directionality is assured. These modules are applicable to multiple networking scenarios, which may have very diverse constraints on the type of client-layer flexibility that supports the SBVTs. In particular, the switching capacity available for traffic grooming operations can have a significant impact on the overall efficiency of this type of deployment. This paper proposes a framework to optimize multi-period planning scenarios for SBVT-enabled optical networks, which is utilized to study the interaction between the transport and client layers under different grooming and switching conditions. The analysis reveals that encouraging multi-hop grooming at the expense of further usage of client interfaces is beneficial in scenarios where switching capacity is most constrained.