Research On The Cooperative Mechanism Of TWDM-PON Based Mobile Fronthaul Network

With the rapid development of intelligent terminal,mobile network faces great traffic pressure.Recently,C-RAN-based radio access network with concentrated BBUs(baseband processing unit)and distributed RRUs(remote radio unit)attracts operators’ attention,because it has advantages in increasing network coverage,reducing operating costs.However,the mobile fronthaul network(the network connecting BBUs and RRUs)faces greater bandwidth and lower latency pressure in 5G.Currently,the industry has proposed a solution to split the functions of the BBU/RRU and use TWDM-PON networks for mobile fronthaul network.Realizing the resource cooperation and the delay requirements of different services is the key problem for TWDM-PON based mobile fronthaul network.This thesis focuses on the study of the cooperative mechanism of TWDM-PON based mobile fronthaul network.It mainly studies from two aspects of unified control and resource allocation of TWDM-PON network.The goal is to achieve the unified control of TWDM-PON network and the low latency and high efficiency resource allocation.The main innovations are as follows:In the aspect of cooperative control,this thesis focuses on the cooperative control between different TWDM-PON networks based mobile fronthaul network.In order to achieve smooth evolution of mobile network,4G/5G networks will coexist in the future.In addition,it is difficult to avoid the multi-vendor and multi-standard TWDM-PON networks in the mobile fronthaul network.There are private interfaces and policies between different TWDM-PON networks.In this thesis,the unified control plane of TWDM-PON is built to shield the equipment differences and achieve cooperative control of mobile fronthaul network resources.The experiments on the equipment platform verify the capability of the unified control plane in terms of cooperative control.In the aspect of resource allocation,this thesis focuses on resource optimization on TWDM-PON.In order to fully exploit the advantages of TWDM-PON resources,it is important to have a high efficiency and low latency resource algorithm.In this thesis,a prediction mechanism is introduced in the polling cycle of TWDM-PON resources.In order to reduce the packet delay,the polling cycle is divided into delay-sensitive sub-cycles and non-delay-sensitive sub-cycles.The simulation results show that the proposed polling algorithm based on prediction and service differentiation has advantages over the two classic TWDM-PON resource polling algorithms in reducing the average packet delay and improving the utilization of the uplink channel.