Research On Resource Optimization Under "IP+optical" Collaborative Architecture

With the rapid development of emerging services such as 4K video,VR,Internet of Things,the backbone network traffic is growing rapidly.The backbone network uses cascade"IP+Optical"network mode to serve the fast-growing needs of users.In cascade mode,the IP layer adopts a dual-plane hierarchical network architecture to aggregating services,and the optical layer adopts a flat structure to solve the problem of large capacity and long distance transmission.In the"IP+Optical"cooperative network architecture,there are generally two different types of service processing modes for service requests:optical layer direct transmission and IP-optical cooperative transmission.The adaptive threshold and the resource optimization of the two service transmission modes under the"IP+Optical"cooperative architecture is a key research topic.In this paper,two different service processing modes under the"IP+Optical"collaborative architecture are taken as the main line,and it is analyzed from the adaptability analysis and the resource allocation mechanism perspectives.It mainly focuses on the adaptive threshold problem of the two service processing mode under the"IP + Optical"cooperative network architecture,the routing and spectrum resource allocation problem in the elastic optical networks,and the joint resource scheduling problem in the multi-layer networks.The simulation verification and performance analysis are carried out on the simulation platform.Specifically,the main research content and innovations of this paper include:1.A bandwidth threshold adaptive algorithm for IP switching and optical switching under the"IP + Optical"cooperative architecture is proposed.Aiming at the reasonable division range between the two transmission modes in the"IP+Optical"cooperative network,this paper establishes the cost model of IP switching and OTN switching under different service parameters and network parameters,and studies the bandwidth threshold algorithm based on hardware cost and optical port cost under the new"IP+Optical"cooperative architecture,which using OTN devices as the transport layer infrastructure.Through a large number of simulation experiments,the bandwidth threshold based on hardware cost for IP switching and OTN switching under different switching granularity and port rate are compared when the number of service requests are changed.At the same time,by calculating the minimum hardware cost and the corresponding port configuration under different parameters,the results of bandwidth threshold based on hardware cost are verified and analyzed.The simulation results show that when average bandwidth excessing 280Mbps,the hardware cost of OTN switching is lower in comparison with the hardware cost of the IP switching when switching granularity is 1.25 Gb/s.Furthermore,aiming at the problem of the increased number of the optical cables and network hops caused by the optical layer direct transmission,this study simulates and validates the bandwidth threshold based on optical port cost and the forwarding delay of IP switching and OTN switching under different switching granularity and port rate.2.An adaptive routing and spectrum allocation algorithm based on the network energy consumption is proposed.Under the optical layer direct transmission mode,for the problem of high energy consumption in elastic optical network,the algorithm maps the feasible solution to the genetic operator with the idea of genetic algorithm,and then performs crossover and mutation operations to iteratively generate a better set of feasible solutions,so as to find an approximate optimal solution for service requests.The simulation results show that compared with other benchmark algorithms such as EAMGSP,IF and KSP(k=3)in different network topologies,the SW-Iteration algorithm proposed in this study can effectively utilize the spectrum resources in networks and reduce the network energy consumption while guaranteeing the blocking rate.Especially when the network is large,the performance advantages of the proposed algorithm in blocking rate and network energy consumption are more obviously.Further,an adaptive routing and spectrum allocation algorithm based on spectrum adjacency is proposed.Under the optical layer direct transmission mode,for the problem of how to efficiently allocate spectrum resources in the elastic optical network,the algorithm finds all the idle spectrum blocks that can meet the service requirements on the available routing paths,and then calculates the path spectrum adjacency and the link spectrum adjacency of each spectrum block respectively.Finally,the spectrum blocks with the largest spectrum adjacency are allocated to service requests according to the requirements.Simulation results indicate that DA-FASA exhibits highly efficient performance with regard to the bandwidth blocking probability and the spectrum utilization ratio in static and dynamic network scenarios,compared with the benchmark algorithms.3.A joint multi-layer resource scheduling algorithm based on the virtual transport network is proposed.Under the IP-optical cooperative transmission mode,the algorithm aiming at the uneven resource allocation of different types of services in the backbone networks.The algorithm mainly includes three sub-problems:resource description of virtual transport network,virtual transport network service mapping,and virtual transport network replanning.The proposed algorithm effectively integrated slices the router resources and optical network resources in resource pool,and then establishes the virtual transport network according to the service requirements.The corresponding resources are allocated to virtual requests through VTN,so as to optimize the network resource allocation.The simulation results show that the proposed algorithm can effectively utilize the network resources,and improve the utilization of network resources under the condition of guaranteeing the average virtual request acceptance ratio.