Research On Routing And Optical Code Allocation Algorithm In Optical Code Division Multiplexing Networks

In wavelength division multiplexing(WDM)optical networks,the usage of optical fibers and the number of wavelengths multiplexed on each optical fiber link seriously affect and restrict the maximum saturation of communication services provided by the network.Therefore,optical code granularity is introduced to form optical code division multiplexing(OCDM)network.How to choose the best route for optical connection requests and allocate suitable optical code resources to optimize the overall performance of the network is a very important research topic.In this paper,the Routing and Optical Code Assignment(ROCA)algorithm in OCDM network is deeply studied and analyzed.First of all,this paper studies the ROCA strategy based on the service level,and puts forward the routing allocation strategy based on PCE and the routing algorithm based on the service level.For the problem of optical code resource allocation,two kinds of optical code allocation algorithms based on service level are proposed: fixed optical code number method and fixed optical code number method.Secondly,the description of network resources is extended to three-dimensional description of route,optical code and time slot,and an optical code resource reservation algorithm with time slot description is proposed,which reduces the generation of optical code resource fragments and reduces the network blocking rate.After that,a preemption-based multi-priority ROCA algorithm is proposed by combining routing algorithm and optical code resource reservation algorithm,which improves the network resource utilization rate.Lastly,in order to overcome the shortage of fixed optical codes in uniform wavelength switching,a new multi-granularity optical cross-connect structure supporting non-uniform wavelength switching is proposed,and on this basis,a flexible and extensible optical code allocation algorithm supporting non-uniform wavelength switching is proposed,which makes wavelength grouping more flexible,can automatically select the most suitable granularity under different traffic conditions,and improves the allocation efficiency of the system.