Research On Key Technology Of Intelligent Software Defined Optical Access Network

As the "last mile" network connecting users,optical access networks are facing increasing challenges in terms of architectural flexibility,broadband utilization,and security and reliability of data resources.Software-defined optical access network(SDN)effectively solves the above problems,but it still faces the following challenges: first,the differences between different optical access network devices make it difficult to unify network resources management;second,the traditional automatic migration scheme of optical network units(ONU)has large errors in ONU data collection;third,it focuses too much on improving the registration efficiency of ONU in SDN,thus ignoring the possible security risks of the system.In this paper,the following research work is carried out in terms of building an SDN-based TWDM-PON architecture and improving the efficiency of ONU registration at the subscriber side.(1)To address the problem of low resource utilization in traditional TWDM-PON networks,this paper analyzes the technical characteristics of offline resource allocation and online resource allocation and designs a network architecture for cross-layer control of TWDMPON based on SDN.This architecture first extends the Open Flow protocol and describes the information interaction process in this network architecture.Then it compares the architecture with two traditional network architecture solutions and clarifies that the architecture uses the idea of hierarchical control to enhance the stability of the architecture by deploying Open Flow agents at the optical network terminals to allow OLTs to gain partial controller privileges and extend the control depth to the optical network units.(2)To address the problem of inaccurate prediction of the number of ONUs in TWDMPON networks,this paper designs a scheme for ONU migration based on time series.First,the conditions for ONU migration are redefined,and then an ONU migratable registration model is designed with the fiber-to-the-home(FTTH)topology,and the adaptive algorithm is analyzed;second,a three-time smoothing prediction algorithm is introduced to predict the number of ONUs;finally,the simulation experiment comparison results prove that the three-time smoothing prediction scheme based on the time series can effectively solve the ONU migration scheme Finally,the simulation experimental comparison results prove that the three-time smoothing prediction scheme based on time series can effectively solve the problem of insufficient accuracy of ONU data in ONU migration scheme,and then improve the accuracy of ONU registration windowing,which provides a strong support for the research of ONU registration efficiency.(3)To address the problem of collecting and protecting ONU data in the time series model,this paper designs a blockchain-based network online data storage scheme.First,the distributed structure,trustworthiness,tamper-evident,and traceability of blockchain are analyzed;second,a blockchain-based system model is designed and the LLDP protocol is used to collect global network link state information,while the controller in the SDN network is used along to perform the link discovery process,followed by building the block model and outlining the combination of SDN and TWDM-PON systems with blockchain ONU data storage process;finally,the process of ONU data acquisition is elaborated,and the scheme not only guarantees data integrity,but also makes up for the lack of ONU data when studying time series.