Research On Four-granularity Optical Switching Path Algorithm For PCE

With the proposal of new infrastructure,5G communication network promotes the development of the network from the "optical + electric" hybrid communication network to the all-optical communication network.The underlying network nodes of the traditional optical network architecture need to calculate and transmit a large number of user requests,which is easy to cause the breakdown of the whole network due to the excessive load.Therefore,it is impossible to meet the diversified services by merely adding optical forwarding equipment.In this paper,the Software Defined Network(SDN)is integrated to separate the control plane from the data plane,so that the computing function is concentrated in the control layer,and the intelligent four-granularity optical switching network is constructed by using optical cross-connect technology.The new network architecture is more flexible and requires the appropriate resource allocation algorithm.Therefore,the service transmission algorithm of four-granularity optical switching network is studied in this paper,and the details are as follows:Firstly,the SDN and multi-granularity optical switching technology are studied.The Stateful Path Computing Element(S-PCE)is used as the controller of the control layer to construct the software-defined four-granularity optical switching network structure.The network control layer centrally manages the entire network,and cooperates with the underlying GMPLS distributed structure to complete data forwarding,and finally realizes the transition to the software-defined optical network.Secondly,the routing resource allocation algorithm of software-defined fourgranularity network is studied.First,on the basis of improving the traditional CSPF routing algorithm,the constrained shortest path first algorithm based on code group routing is proposed.Under the condition of satisfying the bandwidth constraint,the optical codes in the path are bundled together to transmit the services according to the idea of Code Group Routing Entity(CGRE),which can effectively improve the occupancy rate of network bandwidth.Second,aiming at the problem of insufficient utilization of optical code resources,a fibonacci optical code allocation algorithm was proposed.Under the control of S-PCE,the network uses the fibonacci sequence to dynamically and unfixed the optical code,and pre-calculates the optical code service request,which can efficiently utilize the optical code resources to complete the path calculation function.Finally,the four-granularity optical switching structure with CGRE and the fourgranularity optical switching structure based on Optical Code Division Multiplexing(OCDM)are compared,and the analysis shows that the introduction of CGRE can reduce the consumption of network resources.At the same time,the proposed routing and optical code allocation algorithm is simulated and analyzed in terms of wavelength utilization,optical code utilization and throughput,etc.,and the superiority of the proposed algorithm is verified.