| Ultra wideband-high performance optical access network(OAN)and 5G mobile communication network are forming the foundation of information network of "New Infrastructure".The next generation passive optical network(NG-PON)architecture puts forward higher requirements for the security and reliability of OAN.It is urgent to explore efficient methods and technologies for link security management,due to the lack of effective link state awareness and security management capabilities in the traditional PON link security management system.In order to meet the above requirements,this thesis,aiming at the practical application of two-dimensional optical-coding passive optical network link health detection system(2DOC-PON-LHDS),deeply studies the key issues such as accurate criterion of link state,interference of massive densely distributed customers and complex environment adaptability.First,the dynamic interaction process model between the failure-detecting light pulses and the fiber link elements in 2DOC-PON-LHDS is established.The equivalent reflection coefficient is defined to represent the actual reflection ability of the coding FBG to the energy of the failure-detecting light pulses.Considering the dynamic interaction process between the failure-detecting light pulses and the wavelength dependent devices and the power splitter,the multi-wavelength link state signal sequence at the system receiver is obtained.The comprehensive influence of parameters of the fiber link elements on the multi-wavelength link state signal sequence is simulated and analyzed.The experimental results of the 2DOC-PONLHDS show that the proposed model can accurately describe the evolution of the transmission and reflection of the failure-detecting light pulses along the fiber link.Next,the distribution model for massive densely distributed customers in 2DOC-PONLHDS is established,and the influence of major parameters in system on the multi-customers interference probability is explored.The characteristic wavelength is allocated to the interference customers of the sparse distribution.The coding method of sum-dissimilarity and the code allocation rules are proposed for the interference customers of dense distribution.Further,the link state recognition algorithm based on power integral clustering of the superimposed signals is proposed.The experimental results show that the interference solutions can avoid the same code type and decrease the overlap degree of the link state signals significantly.The link state recognition algorithm achieves the false alarm rate of 0.9‰ after optimization.Next,based on the dynamic interaction process model,the link state signal considering the complex environment conditions is derived,and its power variation ratio with the changing of temperature is obtained.The influence of the central wavelength mismatch on the link state signal is simulated and analyzed.A tunable laser based temperature compensation scheme for2DOC-PON-LHDS is proposed to offset the impact of temperature variation on the link state signal.The experimental results show that the proposed method is effective,and a compensation range from-35? to 80? is achieved while the power variation ratio of link state signal is from 0.96 to 1.11.Then,the intelligent link management technology for OAN based on 2DOC-PON-LHDS is studied.An intelligent link management structure for multi-hop optical distribution network,which integrates the Raman amplification,network monitoring,link protection and intelligent remote node,is proposed.For the multi-hop structure of NG-PON2 and the deployment of WDM-PON,the multi-hop FBG encoder and a WDM-PON remote node with uplink and downlink separation are proposed,respectively.2DOC-PON-LHDS is embedded in the ODN intelligent network management system,which successfully realizes the identification of ODN link failure.Finally,this thesis summarizes the work and prospects. |
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