Resource Optimization In Flexibel Optical WDM Networks

With the quickly development of Internet technology, rates of traffic are increasing and the more granularity. Traditional fixed grid WDM network cannot meet the increasingly needs. Flexible optical wavelength division multiplexing network can meet the growing needs. Compared with the traditional fixed-grid flexible optical network optical network routing and resource allocation problem is more complex. Traditional routing and wavelength assignment methods have been unable to resolve a flexible optical network resource optimization problems. In this paper, three flexible optical network resource optimization problems are researched, they are a routing and resource allocation strategy considering intermediate nodes modulation format conversion ability, transmission resource optimization strategies against multiple faults with multipath provisioning, resource sharing and multi-path combining strategies against multiple faults.Flexible optical networks effectively improves the network spectrum utilization efficiency and opens up new prospects for future network architecture. However, the spectrum fragmentations and the blocks caused by them are still bottleneck of flexible optical network. In this paper, the strategy that at the intermediate node converse modulation format without affecting the other traffic. The strategy using in flexible optical network resource optimization is expressed by dynamic routing, modulation format and spectrum assignment. Simulation results show that the proposed dynamic routing modulation format and spectrum allocation algorithm gets spectrum efficiency improvement by5%and blocking rate reduction by20%without additional bandwidth or changing existing traffic in the flexible optical WDM network. In survival scenarios, the proposed strategy can improve the recovery rate effectively and network survivability.With the natural disasters and other large-scale human-made disasters, survivability against multi-failures in optical networks has become a hot research topic. In this paper, a flexible optical network resource optimization against multiple failures starts with the introduction of multi-path transmission mechanism. Flexible optical network for multi-path transmission strategy is studied and analyzed. By numerical calculating the required bandwidth, quantitative analysis the advantage of multipath provisioning compared with single-path provisioning. Establish an ILP model for flexible optical network with multipath provisioning transmission strategy. It is solved and analyzed. The results prove that the proposed flexible optical network using multipath provisioning transmission against multiple failures saves network resources, while ensures the effective transmission performance and improves the efficiency.Resource sharing in flexible optical networks has been shown improving the resource efficiency. Flexible optical network resource sharing not only share wavelength or sub-wavelength, but also flexible spectrum. In this paper, optimization problem in a flexible optical networks with resource sharing resources and multipath provisioning against multiple faults is studied. Considering the characteristics of a flexible optical network transmission, resources sharing and the advantages of multipath provisioning, we propose a resource optimization strategy, and design a developed genetic algorithm to achieve the proposed strategy. Resource allocation algorithm is encoded by traffic sort. The developed algorithm uses two-point crossovers, roulette wheel selection algorithm, mutation and other effective operations. The simulation results show that the proposed strategy and algorithm can effectively improve the efficiency of network resources.