Optical Network Routing And Wavelength Assignment Problems

With the development of informantion society and the explosive growth of Internet,great changes has taken place in our life. Information is more and more important to us.With the coming of the "INTERNET era", a lot of new informantion service will be in useand the needs of bandwidth will become more and more. Thus emerges an acute need forvery high-bandwidth transport network facilities, whose capabilities are much beyond thosethat current high-speed network can provide. Wavelength-division multiplexing(WDM) isnow coming into our sight to satisfy the urgent needs. Because the WDM technology canfully utilize the enormous bandwidth of the optical fiber, the capacity of the network isgreatly improved. WDM technology is now being the most attractable technology in widebackbone network. All-optical network based on the concept of WDM and wavelengthrouting is considered as a candidate for the next generation transport network.Because the number of the wavelengths which are multiplexed in a single fiber islimited, without wavelength conversion, all the communication of the route must use thesame wavelength, namely wavelength continuity limited. One of the key issues in opticalnetwork design is to optimize Routing and Wavelength Assignment(RWA) for lightpaths.RWA solves how to find out an appropriate lightpath and assign a wavelength resonably inorder to make full use of the limited resource and provide communication capability aslarge as possible. So we must perform effective routing and wavelength assignment(RWA)to make the best use of the sources in the network.As present, large-scale all optical network is not easily realized, so the study of RWAand its engineering problems on small-scale and middle-scale optical network hasimportant academic and realistic significance. The major research works in this paper are:1. to introduce the optical network ,the techonology of WDM and some importantoptical laboratories abroad.2. to introduce the concept of RWA and significance of research;to research differenttype of RWA—static and dynamic, classify and compare some particularly assignments.3. In WDM network, wavelength conversion is a key technology. Limited by thetechnology and cost of the wavelength conversion, how to get higher effective of theoptical network by placing less wavelength conversion is important. This paper proposed aheuristic wavelength assignment(WA) which minimize the number of wavelengthconversion for WDM optical network with sparse-limited wavelength conversion. Theanalytical and simulation results show that when the traffic is heavy, the proposed WA canprovide a much lower blocking probability than some other previously proposed WAalgorithms.4. to make some research on WA of parallel algorithms on optical network, analyze thecommunication patterns of parallel algorithms of matrix multiplication.