PCE-based Control Model And Survival Strategy In Flex-Grid Optical Network

Along with the popularization of the internet and the growing demand from customers,the data almost explodes exponentially on a global scale.Up to now,for the wavelength division multiplexing(WDM)in the core network,the bit rate within single wavelength is now under the transition from 10 Gpbs to 40 Gbps and 100 Gbps.But the fix grid WDM comes to its limit,and connot meet the demand of 400 Gbps and higher bit rate.Thus,this lays solid foundations for the Flex-Grid.Meanwhile,the GMPLS-based control plane involved in intelligent optical networks has matured,and the Internet Engineering Task Force(IETF)has standardized the path computation element(PCE),producing the control architecture based on GMPLS and PCE.However,the upgrade of transport plane will definitely result in the updates in control techniques.The conventional distributed control model fails to satisfy the requirements of Flex-Grid,like frequency continuity,frequency fragment,etc.In this paper,a semi-centralized control scheme is proposed---a control model based on PCE for Flex-Grid networks,to address challenges and problems like routing,signaling as well as the control over the overall networks.With the expansion of the network scale and the increase in complexity of network environments,multi-failure probability has significantly improved.In the face of multiple failures especially simultaneous failures,the conventional dedicated protection and shared protection loss their excellent protection effect.In Flex-Grid optical network,spontaneous service failure will cause the loss of large amounts of users' data.To decrease the traffic loss caused by multiple failures,this subject introduces the concept of correlated risk between different traffics,proposing a novel routing and spectrum assignment algorithm named shared-path protection algorithm with correlated risk against multiple failures.The main work of this paper includes the following aspects:1.Summarized the development of the intelligent optical network,and then proposed the PCE-based semi-centralized control model considering the new features for Flex-Grid optical network;2.Researched on the PCE-based routing and spectrum assignment(RSA),and improved the standard backward-recursive PCE-based computation(BRPC)procedure,proposing the parallel path calculation-backward path selection(PPC-BRPS)algorithm suitable for Flex-Grid optical network;3.Designed and established the Flex-Grid experimental platform consisting of four domains and 200 control nodes to realize and validate our proposed semi-centralized control model;4.Proposed the shared-path protection with correlated risk algorithm(SPP_CR)against multiple failures,and established a simulation platform to compare the new algorithm with conventional path protection schemes.