Study On Modular Construction Methods Of Large-scale Optical Cross-connects

Optical cross-connect(OXC)is one of the essential components of a wavelength-routed optical network node.Its main function is to perform optical path switching.With the emergence of high-bandwidth services such as high-definition television,cloud computing,and online gaming,the demand for network bandwidth has exploded,and higher and higher requirements have been placed on the size of OXC.However,the scalability of traditional OXC is insufficient.The specific manifestation is that the internal wiring is complicated and the required optical switch scale increases with the number of OXC ports.To this end,this thesis studies the construction method of large-scale OXC,and proposes two modular OXC structures.Firstly,this thesis proposes a method for constructing a large-scale OXC structure using optical space switches(OSs).The OS-based OXC consists of wavelength multiplexers, wavelength demultiplexers,and a series of OSs working at different wavelengths.The construction method can be divided into two steps.Firstly,the OSs working at different wavelengths are decomposed into a three-stage Clos network interconnected by small-scale OSs;secondly,corresponding fiber links in different Clos networks are combined into multi-core fiber links so that the combined multi-core fiber link and small-scale OS form multiple small-scale OXC modules.After modularization,a large-scale OXC will be interconnected by a series of small-scale OXC modules.This thesis verified that its power penalty and other indicators can meet the needs of the application through experiments.Secondly,this thesis studies the method of constructing large-scale OXC with wavelength selective switches(WSSs).The × WSS-based OXC is composed of 1 × WSSs and × 1 WSSs.The construction method can be divided into three steps.The first step is to modularize the wiring network between the WSSs in OXC.The second step is to decompose the WSSs,specifically,according to the first step of the modularization process,each WSS is replaced with multiple small-scale WSS equivalents;the third step is to combine the decomposed WSS and connected network modules to form a series of small-scale OXCs.After the above three steps,the large-scale OXC has become a series of small-scale OXC and small-scale WSS interconnected switching network.We further evaluated the performance of this modular OXC by using simulation software.The two modular OXC structures proposed in this thesis have the following advantages:(1)The structures are interconnected by small-scale OXC modules with low connection complexity and good scalability;(2)They are non-blocking and the wavelength routing process is simple.