Wdm Optical Networks And Multi-layer Network Survivability

Since the 1990s, the rapid development of data service promotes the rapid development of the telecommunication transmission network in the direction of high-bandwidth and multi-service. The introduction of DWDM technology makes the transmission network acquire a potentially unlimited bandwidth. In such a high-speed and multi-service transmission network, any failure will cause tremendous impact and losses. Therefore, the research for survivability is more urgent than the traditional network.In chapter 2, it makes an extensive and systematical summarization of single-layer network survivability based on reading lots of references about survivability technology and former method on the survivability schemes. Then an analysis is made for the coordination mechanisms and allocation of spare capacity in multi-layer networks.Survivability technology in optical layer has many advantages, such as rapid recovery, high reliability, low cost and strong transparency. Shared-Path Protection is always the hotspot in research due to the higher resource utilization and faster protection. Because of the dynamic characteristics of network operations increasingly showing, WDM networks require the ability to respond quickly to dynamic operations. In a dynamic environment, well designed routing and bandwidth allocation schemes are very important to improve the utilization of network resources and reduce congestion rate.In chapter 3, it researches the Path Protection algorithm in WDM networks in the dynamic operations environment. It focuses on the protection of a dedicated path and share path protection strategy for survival Routing Solutions, which means the network link weighted approach. Finally, several dynamic protection algorithms are simulated and their performances are analyzed.The survivability in multi-layer networks has become a key technology which is in urgent need of a breakthrough. There are two key issues of the survivability in multi-layer networks. One is how to establish an effective coordination mechanism which can avoid competition between the different layers. The other is how to raise the level of cooperation and sharing among spare capacity.In chapter 4, a comprehensive strategy and an effective coordination mechanism of SDH over WDM network are proposed. After that, we are focused on the study of the spare capacity allocation in multi-layer networks and propose a new method of resource allocation. This method extends the idea of resource sharing in a single network to the multi-layer networks and makes the capacity sharing maximum in different layers. Then we establish the integer linear programming (ILP) model for the analysis. The results show that the new method can significantly reduce the cost of protecting resources. Finally,aiming at the multi-network Failure Propagation phenomenon, a method of joint layer resources allocation is proposed. This method guarantees that link failure in the lower layer will not affect the working path and the protection path in the upper layer. On this basis and according to several different schemes, we discussed that how much protection capacity should be reserved to guarantee the recovery of affected operations. Meanwhile, the ILP model is constructed and analyzed.