Study On The Survivability And Rwa For WDM Optical Rings

Wavelength Division Multiplex (WDM) networks will play an important "role in future backbone networks. How to programming the wavelength reasonably in the networks is a key issue. And due to the specialty of high-speed, huge-capacity and multi-services of optical networks, the networks without the nice survivability are not allowed to be employed. In the paper, these key technologies of wavelength routing ring networks, the Routing and Wavelength Assignment (RWA) and the survivability of WRN, is researched in detail.1. The RWA is analyzed. Graph Theory is an effective tool for the problem. We discussed the problem of RWA for small WDM rings, and the restriction of Access Station to wavelength is avoided if we adopt Non-blocking Access Station (NAS). These are groundwork for next phases.2. The survivability of Optical networks, i.e. the protection and restoration for failure, are discussed. Whereas the vast success of SDH networks, it is WDM rings to be a fact firstly. Some kinds of WDMself-healing rings are discussed and compared.3.Utilized the method of vertices coloring, an initiatory arithmetic is proposed according to WDM rings, 'an improved Greedy algorithm'. Simulation on computer is carried out to compare this problem with a used one, the new algorithm acquires the higher wavelength efficiency. Then the algorithm is used to compare the demand of some different rings. The result show there is obvious difference for these rings especially for big networks. It offers the consult and the gist for the building of WDM networks. Two strict wavelength lower limits are achieved to estimating the RWA algorithm for WDM rings. It can be used as the criterion of the utilizing rate of WDM network resource.