Research On Space-time-frequency Contention Resolution Algorithm In Space Division Multiplexing Elastic Optical Network Nodes

Compared with the traditional fixed grid wavelength division multiplexing optical network,the space division multiplexing elastic optical networks can flexibly allocate bandwidth according to the size of the request,and allow multiple cores to transmit requests in parallel,which greatly increases the network capacity.However,the rapid development of space division multiplexing elastic optical networks also faces certain challenges.On the one hand,when a lot of requests passes through a space division multiplexing elastic optical networks node,the space-spectrum consistency needs to be satisfied.So there is a problem of requests competing for spectrum resources of the same destination port.On the other hand,when the same spectrum of adjacent cores/modes is occupied,crosstalk problem will be happened.In order to effectively resolve the above problems,in the thesis,we jointly consider the resource occupation in the space-time-frequency domain and the crosstalk between adjacent fiber cores/mode in the all-optical nodes of the space division multiplexing elastic optical networks.The major innovations and achievements of the thesis are as follows:Firstly,an all-optical dynamic function node architecture based on shared limited spectrum converters and fiber delay lines(DASLF)is studied in this thesis.Based on this node architecture,a space-time-frequency domain joint contention solving algorithm(STFJCSA)is proposed.In the STFJCSA,a core switching method based on spectrum aggregation is designed in the space-frequency domain to resolve conflicts problem.Then,a spectrum conversion method with the minimum discrete degree of spectrum conversion is designed to resolve still conflict requests in the time-frequency domain.The results reveal the DASLF-STFJCSA proposed in this thesis can decrease bandwidth blocking probability of request,reduce the usage of limited range spectrum converters and fiber delay lines.Secondly,a layer all-optical node architecture based on resource reservations and shared limited spectrum converters(LARSL)is studied in this thesis.Based on this node architecture,a crosstalk avoidance-based on space,frequency and time domain combing conflict resolution algorithm(CACRA)is proposed.In the CACRA,a crosstalk-avoidance resource calculation method using sliding window is designed to reduce crosstalk and decrease bandwidth blocking probability in the space-frequency domain.Moreover,atime domain resource reservation module is designed to reserve still conflicting requests to next scheduling time for further reducing the bandwidth blocking probability in the time domain.The results reveal the LARSL-CACRA designed in this thesis can decrease bandwidth blocking probability and reduce the usage of limited range spectrum converters.