Study On Key Technology Of Wson Networks Constrained Routing Calculation

In the 21st century, with the development of internet technology such as peer-to-peer services, the world networks band width demand's yearly rate reaches as high as 50%-100%. The next transport networks drove by broadband data services are evolving to high speed, large capacity, ultra long distance and intelligent network is the trend. WSON (Wavelength Switched Optical Networks), as the extended of ASON (Automatically Switched Optical Network), has the extra ability intelligent wavelength allocation. In the WSON's optical layer, the cross connection is lambda which is different with circuit layer cross connection in switching. On the one hand, wavelength continuity constrains the optical control plane routing and wavelength allocation (RWA) due to un-mature all-optical wavelength conversation. In order to resolve the above problems, the key technologies about two types of constrain routing computation are analyzed in GMPLS-based (Generalized Multiprotocol Label Switching) distributed control plane and PCE-based (Path Computation Element) centralized control plane. The main innovative contributions are listed as follows.Firstly, complete the WSON standard requirements analysis and technical research, including WSON network GMPLS & PCE architecture, and WSON architecture with impairment, and RWA information model, the final analysis to support the impairment required, we need the control plane protocol OSPF and the PCEP protocol extensions.Secondly, in order to solve the network blocking and Load Balance problem, a new Load Balance strategy is proposed, in this strategy, a linear formulation is used to describe this problem, a new heuristic algorithm is presented, which tries to implement load balancing in each link. Based on routing strategy in GMPLS-based distributed control plane, a new ant colony optimization-based RWA algorithm is proposed in the article to improve the performance of the network.Thirdly, there is a problem in the centralization network, the information in the PCE is different with the correct information in the current network because of delay. So the wavelength reservation made by the PCE may be failed. To resolve the problem, a new label strategy is proposed in this article to improve the performance of the network.Last, all of the above theories are proved by emulator, and the conclusion will be given at last.