Broadband Optical Access Network Networking Technology

The growing popularity of the Internet and IP video service are the key drivers with the development of broadband access network. Among the various technologies, the optical access network based on the optical fiber has shown its great advantages in the the transmission distance and network bandwidth capacity. In recent years, passive optical network (PON) has received more and more attention in both industrial and research field. A great amount of effort has already been made and is currently going on in developing and standardizing various PON technologies. In this paper, the performance of two PON access methods, i.e. GPON and EPON are compared and analyzed. Firstly, a detailed introduction to GPON and EPON network technologiesis given. Secondly, the signal encapsulation method, signal transmission techniques, Layer 2 data link and bandwidth allocation techniques in the GPON, EPON networks are analyzed. Thirdly, e the PON network performance in terms of the latency, link utilization efficiency and network throughput are also evaluated. The calcualtion results shows that GPON has a higher efficiency and larger throughput than EPON, and has advantages over EPON in providing TDM services. However, GPON also impose stringent requirements on the transmission components/modules, as it has a complex encapsulation process and much less physical layer overheads than EPON. The efficiency of EPON is maily limited by its coding overhead and encapsulation overhead. But EPON relaxes its requirements on the transmission componet/modules, so it can be an effective solution in providing IP data access services. Based on the analysis results, the principles and procedures to construct GPON and EPON networks are finally discussed.