Research Of Data Stream Controlling Mechanism In EPON OLT Chip

As a mature technology of optical access network, EPON with its advantage of low cost, high bandwidth and integration of varieties of business will be more extensively used in China and Asia in the foreseeable future due to the puissant promotion by operators and manufacturers. The core chip determines, to a large extent, the performance and cost of EPON OLT equipment. Therefore, it is necessary and significant to conduct research on it.From the outside perspective, OLT chip should process a variety of complex data streams both from ONU and uplink ports. To improve QoS, the chip has necessity to control the flow size and serving order of data streams in this process. This thesis has made intensive study on these two aspects of controlling mechanisms. Additionally, this thesis designs and implements the function of traffic shaping of the mechanisms. The modified strategy based on game theory for forwarding queue scheduling is also proposed.The first chapter of the thesis introduces the concept of EPON technology and its existing necessity. The architecture of EPON is described and the development trend of the technology is discussed combined with its current situation. The key technologies of EPON are then elaborated, as well as the significance, content and innovation of the research. EPON core chip is systematically reviewed in the second chapter, including an overview of the mainstream products and the co-existence of EPON and GPON chips. Emphasis is placed on the principles and framework of the EPON OLT chip developed by Microelectronics Division, Fiberhome Telecommunications Co., Ltd. Chapter 3 commences the discussion on the importance of data stream controlling. Four major mechanisms employed by the chip, which are traffic policing, congestion control, queue scheduling and traffic shaping, are studied. In the fourth chapter, the analysis of the problem about forwarding queue scheduling is made and the amendment deploying game theory for WRR-based forwarding scheduling is proposed. Relevant simulations and numerical analysis are finished as well. The study in this chapter is an innovation for the whole research subject. Additionally, the emulation and verification for data stream controlling mechanisms are presented in Chapter 5. Chapter 6 reviews the entire article and makes prospect for the future work.