Dynamic bandwidth reallocation for NG-SDH networks based on Real-time Traffic Flow Analysis

Synchronous Digital Hierarchy (SDH) networks are wildly deployed by telecom service providers (SP) around the world. Conventionally, SDH network circuits have to be designed and provisioned beforehand. Circuit profiles, including capacity, circuit route, end points..., have to be assigned before service activations. Any attempt of network re-configuration caused by network failures or traffic congestions will lead to uncertain service interruption. To further increase network availability, SPs have to overbuild their networks or to assign backup route(s) for each critical circuit, which, however, is costly and inefficient. With the introduction of technologies such as Virtual Concatenation (VCAT) and Link Capacity Adjustment Scheme (LCAS) of Next generation SDH (NG-SDH), SPs are able to adjust their SDH circuits at various bandwidth granularities and to hitlessly increase or decrease bandwidth of each circuit. In this study, we propose an effective approach to locate overbuild bandwidth, failed circuits, as well as congested circuits based on real time traffic flow data and network alarm message. Then our approach reallocates overbuilt network bandwidth in responding to network failures or traffic congestions by exploiting the benefit of VCAT and LCAS. Our simulation results show that our approach can significantly improve network availability as well as network resource utilization with minimal cost.