Energy-saving Technology Research Of Optical Networks

With the explosive growth of the scale of networks and the great advances of the Internet technology, the power consumption of networks will keep increasing at very fast speed, resulting in the increasingly severe global energy crisis and the worsening greenhouse effect. Especially in backbone networks, the energy consumption in optical networks plays a significant part of the electricity cost. Therefore, designing or operating an energy-effcient optical network has become a hot spot in this field.For requirements of the service level agreement (SLA), many redundant resources would exist in the network to assure the high availability of the traffic, so that the high power consumption would be obtained. In reference to energy-efficient optical networks, they can be divided into two types approximately, the single-layer and the multi-layer. However, the energy-efficiency has not been considered design for optical networks completely, especially with the service reliability, one of the customers’main concerns.In this dissertation, the main objective is to solve the problem of static routing and wavelength assignment at minimum power consumption. The author studies two cases in optical network planning:availability-guaranteed energy-efficient designs for single-layer optical networks and an availability-guaranteed energy-efficient design for two-layer optical networks.In chapter1, the dissertation’s study background and the assignment of the structure would be introduced.In chapter2, the availability-guaranteed energy-efficient designs for single-layer optical networks with dedicated path-protection and shared path-protection would be discussed respectively. The path-protection mechanism would be employed in order to assure the availability of the traffic. Simultaneously, a sleep mechanism and an iterative routing mechanism would be employed as main energy-efficient mechanisms in both of these two designs. The link weight of the paths can be modified for the iterative rerouting. Thus the backup resources can be switched to sleep mode for the energy-efficient purpose. The fundamental difference between them is that the link weight assignment is respective based on theirselves path-protection strategy in the iterative routing mechanism.In chapter3, the availability-guaranteed energy-efficient designs for two-layer optical networks with dedicated path-protection would be discussed particularly. In IP over WDM networks, the problem of static routing and wavelength assignment is solved by using an auxiliary graph. Initial-sorting and re-sorting would be proposed to select a number of demands whose connections are connected by direct lightpaths and based on the availability-guaranteed energy-efficient design for single-layer optical networks with dedicated path-protection in chapter2. And finally, the power-aware routing algorithm and the traffic grooming algorithm are combined to make more resources into idle mode and reduce the energy-consuming operations, only have a slight impact on availability.In this dissertation, simulation results indicate that the proposed algorithms perform well.And the last is summarizing of this dissertation.