Spectrum Resource Management And Allocation Schemes In Flex-Grid Optical Network

With the rapid development of optical networks, network bandwidth capability and resource flexibility are suffering great challenges. Traditional WDM networks only support a wavelength as the minimum granularity of bandwidth allocation, which cannot meet the traffic requirements of the existing services on bandwidth capacity and flexibility. As a result, the architecture of flex-grid optical networks was proposed. Frequency slot is regarded as the minimum bandwidth granularity in flex-grid optical network, which is more flexible than wavelength granularity. The spectrum efficiency in flex-grid optical network is greatly improved compared to traditional WDM network. However, spectrum fragments will be more and more in dynamic running network due to the flexibility in resource allocation. This will bring a serious problem that the blocking probability raises and resource efficiency declines.In order to address these problems, a routing and spectrum allocation model was proposed in flex-grid optical network. Based on this model, the connection controller, which connected and controlled all the modules, was designed in control plane. At the same time, some new resource management and allocation techniques were explored. The main work is as follows:1. The resource allocation model was presented. The performance in term of theory analysis and simulation results are compared and analyzed with centralized and distributed resource allocation models. The results showed that, the centralized routing and spectrum allocation model based on PCE can optimize the performance in terms of blocking probability and spectrum efficiency.2. Connection controller was designed in control plane of flex-grid optical networks. And it was also implemented in flex-grid optical network platform. Connection controller is able to adapt to spectrum flexibility in networks. At the same time, it also can make the control and management more efficient.3. Based on link information aggregation, a multi-link resource allocation scheme was proposed considering the resources management and allocation in optical networks. In this scheme, multi-ink topology was abstracted and link information was gathered. The simulation results showed that, the computing complexity and time were reduced greatly. A routing scheme with node inclusion limitation was designed according to NIR heuristic algorithm. The simulation results showed that the path length can be optimized and the routing computation time can be reduced by this scheme.