Researches Of Survivability For WDM All Optical Transport Networks

With the increase of communication capacity and modern society's dependenceon communication, survivability of optical network has become a crucial problem.Optical layer protection has characteristic of fast protection rate, high reliability, lowcost and transparent, it can provide a common survivable platform for all kinds oftraffic. However, survivable technology in all transport network (OTN) is differentfrom SDH because the former handle optical signal and the latter handle electricalsignal. A lot of problem of survivability in OTN need to be solved. The cost-effectivesurvivable scheme in OTN and key technology, primary path and protection pathrouting and wavelength assignment (RWA) are the topics in this thesis. First, an analysis of present research situation was given in chapter 1. Second, asummary of the relating concepts and technology of optical network survivability wasgiven in chapter 2, which is the fundamental for farther discussion. Thirdly, some keytechnologies of optical layer protection such as fault monitoring, location, switchingcorporation, protection switching time were studied in chapter 3, a method of opticalpower monitoring for primary path and OTDR monitoring for protection path wasprovided. Then an OMS protection scheme was designed and realized in chapter 4.This paper describers the technical scheme, hardware, software and experimentalresult of the system. The result shows the system is safe and efficient to the protectionof the transport network. Another topic of this paper is RWA algorithms of primary path and protectionpath. In order to improve survivability of optical network, a new routing andwavelength assignment algorithms -diverse fiber physical routing algorithms ispresented. This paper presents the idea, Integer Linear Programs (ILP) and heuristicalgorithms, simulation model and example. The result shows that diverse fiberphysical routing algorithm is help to avoid protection fail because optical cable cut orcommunication duct dent, so it can decrease protection fail probability.