Research On Dynamic Bandwidth Allocation Algorithm Based On Combination-matching Mechanism In Optical Access Network

In recent years,the continuous progress of science and technology has promoted the rapid development of the telecommunications industry.The rapid expansion of the network user size and network data volume has put forward severe requirements for network transmission delay,but also led to an exponential increase in system energy consumption.Therefore,the innovation of access network architecture has become an inevitable trend.Ethernet-based passive optical network(EPON)has become the best choice for next generation bandwidth access network because of its fast data transmission,low energy consumption and flexible networking.Among them,bandwidth allocation algorithm is one of the core technologies in EPON system.Efficient dynamic bandwidth allocation algorithm can improve the utilization of bandwidth resources,shorten the data transmission delay and reduce the energy consumption of the system.In this thesis,the dynamic bandwidth allocation algorithm based on combination pairing mechanism in optical access network is studied.Firstly,this thesis proposes a bandwidth allocation algorithm based on combinatorial pairing mechanism,which optimizes two important network performance indicators: data delay and energy efficiency to the greatest extent,taking into account the difference between upstream and downstream bandwidth requests.The simulation network model is constructed by the discrete event simulation library,the scheduling algorithm of optical network unit and optical line terminal is designed,the allocation strategy of data transmission time window is constructed,and the general energy saving model is established.Finally,the simulation results and analysis of system cycle length,data delay and energy-saving efficiency are given.Secondly,a numerical model of bandwidth allocation algorithm based on combined pairing mechanism is established.By introducing the M/M/1 queuing theory model,the cycle length formula,the up-link delay formula and the down-link delay formula are deduced in detail,and the network performance of the bandwidth scheduling algorithm is analyzed from the point of view of the mathematical model.The simulation results are compared with the numerical results to show the correctness of the simulation scheme and the numerical model.Finally,by comparing the bandwidth allocation algorithm based on combination pairing mechanism with the traditional bandwidth allocation algorithm in all aspects of network performance,we can conclude that the combination pairing mechanism proposed in this thesis has obvious effect on data delay performance and energy saving.This thesis provides important scheduling schemes and energy-saving strategies for the research of bandwidth allocation algorithm in EPON system,and achieves good results in delay and energy-saving.It also provides the corresponding scheme reference for further optimization of bandwidth allocation algorithm,which has important theoretical guidance and practical application value.