New Optical Access Network Scheme Design And Bandwidth Allocation Algorithm

In recent years, with the rapid development of mobile Internet and telecommunication services, user demands for network also become diversified development, and gradually developed into multi-service type of data multimedia. With the increasing demands of network bandwidth and quality of service, the existing optical access network solution is difficult to meet the existing network requirements and can't meet the requirements of the next generation optical access network.Therefore, this paper presents a new optical access network research,which combines TWDM (WDM) and time-division multiplexing (TDM)techniques. We propose TWDM-based multi-OLT PON system architecture (TWDM- PON). Considering the multi-service isolation,end-to-end delay and user service level, we propose a new dynamic bandwidth algorithm to reduce the business delay, expand the total bandwidth of the network and improve the QoS of different business grades.Based on the National High Technology Research and Development Program ("863 "Program) of China and the National Natural Science Foundation of China, this paper studies the TWDM-MO-PON system structure and the bandwidth allocation algorithm that improve the QoS. The main work and innovations are as follows:1. A new TWDM-MO-PON system structure is proposed, which divides the data of different service types into different communities.For the ONU of the same service type, bandwidth resource scheduling can be implemented on the timeslots, and WDM technology is used among the ONUs of different service types to increase the bandwidth utilization rate of common signal channel. In addition, on the ONU side,both the wireless user and the wired user can access the network at a high rate and realize simultaneous transmission of multiple services,thus meeting the requirement of the next generation access network.2. The multi-service isolation transmission mechanism is proposed.This mechanism classifies services into three Class of Service(CoS) .Service levels are reduced from CoSO to CoS2. Different service class has different wavelength to isolate service type. By using two separate OLTs to process service data, the multi-service rapid distribution processing is realized and the End-to-end delay of the service class is reduced.3. The network performance simulation platform of TWDM-MO-PON is built, and the key functions such as time division multiplexing, wavelength division multiplexing and multi-OLT management are simulated. Finally gather the key indicators such as packet loss rate, network load and bandwidth utilization and we also complete the relevant bandwidth allocation algorithm performance test.4. Aiming at the QoS guarantee of TWDM-MO-PON, we propose QoS improvement method and dynamic wavelength adjustment mechanism in Burst Business. The simulation results show that this method can reduce the packet loss caused by the full queue of high-priority service, and improve the QoS of the higher priority services by different service-level services take different queuing methods.