Study On Mode Transformation Mechanism And Algorithm For VPON In Multisystem-syncretic Optical Access Network

With the explosive growth of network traffic and the emerging of network applications,the existing network architecture has been a new shock.4K high-definition video,mobile devices,high-speed download,VR/AR and other emerging technologies offer higher requirements for fixed networks and mobile networks.In network architecture,to meet the needs of the new network environment,network flattening will be a mainstream of the development of telecommunications networks.It indicates that three-layer metropolitan area network(core layer,convergence layer and access layer)will evolve into the two-layer network architecture.This two-layer architecture includes core layer and metro-access layer.On the other hand,broadband access solutions based on software-defined networks have been proposed to meet the development needs on full business,high bandwidth,easy operation.To achieve the software-defined network in optical access network,the virtualization in optical access network must be realized firstly.Namely,virtual passive optical network(VPON).Considering the smooth evolution of the network and the co-existence of variety access technologies in optical access network,how to achieve the virtualization of multiple access technologies will become an important part of the VPON.This virtualization can realize uniform control of bandwidth resources in multiple access technologies.So the study on mode transformation mechanism and algorithm in multisystem-syncretic access network has both theoretical significance and practical value.This paper mainly focuses on the mode transformation mechanism and algorithm in multisystem-syncretic optical access network.A uniform control mechanism and three mode transformation algorithms are proposed.By simulation,the effectiveness of the proposed scheme is demonstrated.The main contents of this paper are as follows:1)A uniform control mechanism for multiple subsystems(each subsystem corresponds to an access technology)is proposed to realize multiple-subsystem-based virtual passive optical network.By combing the characteristics of multi?point control protocols(MPCP)of WDM-EPON and OFDM-PON,a unified MPCP is proposed.It can realize upstream bandwidth allocation of both WDM-EPON and OFDM-PON.More importantly,it has the function of mode transformation.2)Mode transformation algorithm of single ONU is proposed.It can be divided into four cases.Four mode transformation strategies are designed for each case.By building simulation system of WDM-EPON and OFDM-PON,we analyze the algorithm performances on throughput,load and delay of system.3)By introducing step-variable knapsack model and tag matrix,mode transformation algorithm of multiple ONUs is designed to realize load balancing between subsystems and improve bandwidth utilization of network of multiple subsystems.Besides,the definition of transform ratio is proposed to analyze the capacity of bandwidth transformation.4)Considering the support of dynamic bandwidth allocation for QoS,the mode transformation scenarios of service priority is described.Next,mode transformation algorithm of service priority is designed to improve fairness of bandwidth allocation among different service priorities.