Research On TDM-PON Upstream Bandwidth Allocation Strategy For Deterministic Latency

Passive Optical Network(PON)is considered to be an important technology for service access in future industrial interconnection scenarios due to its low cost and high capacity.Industrial interconnection services require access networks to have deterministic transmission capabilities,such as deterministic delays.However,the existing cooperative dynamic bandwidth allocation(CO-DBA)for mobile fronthaul and fixed bandwidth allocation(FBA)for direct grant both lead to uncertainty of service delay.In bandwidth allocation,how to ensure the deterministic delay of the industrial interconnection services carried by the transmission container(T-CONT)is a key issue faced by the PON-based industrial Internet.Therefore,this thesis studies the TDM-PON upstream bandwidth allocation strategy for deterministic delay,and does the following work in terms of delay model and allocation strategy:1)Aiming at the problem that the differentiated period of T-CONT leads to the conflict of bandwidth resources in its transmission window,thus causing uncertainty of service delay,this thesis proposes a heuristic bandwidth allocation scheme of customized periodic transmission window.This scheme allows the T-CONT to reduce its own window period,thereby increasing the chance of the window being allocated,thereby ensuring the certainty of service delay.At the same time,this thesis establishes a PON network model and constraints based on the transmission window,and uses the Satisfaction Modular Theory(SMT)to solve it.The simulation results show that,compared with the periodic transmission window allocation scheme,this scheme can improve the transmission window and the scheduling success rate of industrial interconnection services.Compared with the SMT solution,the heuristic algorithm can reduce the time cost and ensure the service deterministic delay.2)The optical line terminal(OLT)reserves bandwidth resources for each service,which will lead to the increase of uplink bursts of the optical network unit(ONU),the reduction of bandwidth efficiency,and the uncertainty of service delay.Aiming at this problem,this thesis proposes a transmission window allocation scheme based on backtracking method.The scheme improves the scheduling success rate of the transmission window and industrial interconnection service by backtracking the window that fails to schedule.The simulation results show that,compared with the traditional scheme,the scheme can improve the transmission window and the scheduling success rate of the industrial interconnection service,and ensure the deterministic delay of the service.