Research On Dynamic Multicast RWA Problem In Sparse Light Splitting And Wavelength Conversion Networks

One of the hot issues of optical Networks is how to support the multicast services in WDM optical network the optical network research focus in recent years. There are some special constraints in optical layer multicast, including the wavelength continuity constraint, sparse light splitter configuration constraint and energy injury constraint. Because the multi-constrained multicast routing calculation is very complicated and difficult to achieve, many of the current methods are study the multicast RWA problem under one or two constraints. Because the configuration of splitter is a major cause of light energy injury, and the realization of full wavelength conversion network is still unrealistic, so this work with the aim of reduce the request blocking rate this article and improve network resource utilization, two aspects of the sparse the splitters and wavelength converters configuration of multicast routing and wavelength assignment problem is studied:routing and wavelength assignment are taken into account; routing and wavelength assignment are considered separately, and a new algorithm for M-GRWA is proposed.Firstly, the paper compares the previous multicast routing and wavelength assignment algorithms, summarizes their advantages and disadvantages. Next, design the routing and wavelength assignment algorithm: routing and wavelength assignment are considered separately, a new multicast RWA algorithm is based on the virtual source is proposed-MS-GRWA. When the path is selected, taking the hops of the path and the remaining number of wavelengths into account, according to the network condition to choose the path dynamically. And adhibt the MPH algorithm when construct the light tree, reducing the use of wavelength resources. During the wavelength assignment, in order to make full use of wavelength resources, reduce the network cost, the proposed new wavelength selection formula is consider the cost of wavelengths, the number of the wavelength converters and splitters that the wavelength through, and the wavelength can reach the number of destination nodes. When consider simultaneously, a new algorithm-MC-GRWA is proposed uses the general layer auxiliary graph, completes the wave-length allocation while routing, in the guarantee certain time order of complexity’s situation, reduces the network blocking rate, to reduce the network the cost. The simulation indicates that, compare to the VS-based algorithm MS-GRWA algorithm can reduce the blocking rate, the average wavelength link number by20%,6%. MC-GRWA multicast algorithm compares with MWCT algorithm can reduce the blocking rate by23%。It can be seen under the same conditions, M-GRWA algorithm has optimal performance, achieves the requirements and objectives of original design.