Study On Resource Scheduling And Bandwidth Allocation Algorithm For Multi-service VPON

With the arrival of 5G era,the global economy has entered a period of digital transformation.The types of services continue to increase,and users' demands for services will continue to improve.Therefore,providing differentiated services for users according to business characteristics will become one of the problems that the optical access network in the 5G era needs to solve.This requires the openness and flexibility of optical access networks to be improved.The virtualization technology of optical access network is the key technology to solve the above problems.Among optical access networks,Passive Optical Network(PON)is the most mainstream technology at present,and the virtualization of optical access network is mainly for PON.Virtual Passive Optical Network(VPON)can flexibly realize the virtual networking between users or network devices by constructing virtual links at the logical level,thus providing a guarantee for users to solve differentiated services under multi-service scenarios.Through the programmable control center,VPON can be constructed,and the bandwidth resources between and within VPON can be allocated.In the mean time,the characteristics of openness and flexibility also make the coexistence of multi-standard and multi-Optical Line Terminal(OLT)inevitably appear in the multi-service scenario of VPON,so as to realize the smooth upgrade of network.Therefore,the research on resource scheduling and bandwidth allocation algorithms of VPON under multi-service scenarios is of great significance.In this dissertation,the resource scheduling and bandwidth allocation algorithms of VPON under multi-service scenarios are deeply analyzed and studied.Based on different multi-service VPON scenarios,we build models,analyze data,and propose corresponding resource scheduling algorithm and bandwidth allocation algorithm strategy.Specific research contents are as follows:1)To solve the problem of real-time resource scheduling in multi-standard VPON scenario,an Optical Network Unit(ONU)mode transformation algorithm based on multi-service traffic prediction is proposed.Multi-service traffic prediction combines nonlinear prediction and linear prediction,which not only ensures the real-time performance of traffic prediction,but also effectively improves the accuracy of prediction.The ONU mode transformation algorithm under different load scenarios is proposed and the prediction period is set to carry out the real-time ONU mode transformation.This algorithm effectively realizes the real-time resource scheduling between different subsystems in VPON and ensures the network load balancing.2)To solve the problem of fair bandwidth allocation for different services in multiOLT VPON scenario,a Dynamic Bandwidth Allocation(DBA)algorithm is proposed to optimize user satisfaction.According to different business characteristics,the user satisfaction utility function under VPON is constructed to improve the accuracy of VPON user satisfaction model.The DBA algorithms based on wavelength granularity and time slot granularity are proposed to effectively improve the user's delay satisfaction and bandwidth satisfaction.3)To solve the problems of bandwidth occupancy and the transmission delay of highpriority services in multi-wavelength VPON scenario,a multi-wavelength bandwidth allocation algorithm based on traffic prediction is proposed.The proposed traffic prediction algorithm based on neural network solves the problem that the traditional forecasting scheme can only predict a single polling cycle,and improves the prediction accuracy of multi-service traffic.The construction of DBA cycle eliminates the DBA idle time,reduces the bandwidth occupation caused by a large number of REPORT messages in VPON,and improves the bandwidth utilization.A differentiated service cycle polling mechanism within a single polling cycle is proposed,which reduces the transmission delay of high-priority services caused by the multi-service co-transmission of a single ONU in the offline DBA algorithm,and reduces the average transmission delay of the whole system.