We are developing an optical layer-2 switch network that uses both wavelength-division multiplexing and time-division multiplexing technologies for efficient traffic aggregation in metro networks. For efficient traffic aggregation, path bandwidth control is key because it strongly affects bandwidth utilization efficiency. We propose a fast time-slot allocation method that uses hierarchical calculation, which divides the network-wide bandwidth-allocation problem into small-scale local bandwidth-allocation problems and solves them independently. This method has a much shorter computation complexity and enables dynamic path bandwidth control in large-scale networks. Our network will be able to efficiently accommodate dynamic traffic with limited resources by using the proposed method, leading to cost-effective metro networks.

The traffic of the future aggregation network will dynamically change not only in volume but also destination to support the application of virtualization technology to network edge equipment to achieve cost-effectiveness. Therefore, future aggregation network will have to accommodate this traffic cost-effectively, despite dynamic changes in both volume and destination. To correspond to this trend, in this paper, we propose an optical layer 2 switch network based on bufferless optical time division multiplexing (TDM) and dynamic bandwidth allocation to achieve a future aggregation network cost-effectively. We show here that our proposed network architecture effectively reduced the number of wavelengths and optical interfaces by application of bufferless optical TDM technology and dynamic bandwidth allocation to the aggregation network.