Studies On The ONU Design & Upstream Transmission Algorithm In Gigabit Passive Optical Network

The demand for accessing Internet with high speed and supporting telecommunication network applications has greatly accelerated the development of broadband access network. The Passive Optical Network (PON) technology fits the requirement to access broadly. The newly proposed technique --- GPON, has been publicly accepted by the insider as one of the most efficient and optimal method to resolve the broadband access network and now being paid more and more attention.The issue gives a sketch of the definition of Optical Access Network with its reference configuration and topology structure, introduces the requirement of Media Access Control, compares the three main method of PON– APON, EPON and GPON with their advantage and disadvantage, analyzes the design of ONU system structure in details. This issue mainly focused on the research of GPON upstream transport schedule & distribution algorithm and design for TC adapting sub-layer of the ONU.Based on the traditional Dynamic Bandwidth Assignment algorithm, the issue proposes an improved algorithm determined by different priorities'services and a new schedule method according to the priority and waiting time, then presents the analysis of the two algorithms about their validities and emulations, introduces the chip used for physical layer in details, discourses each module's function of TC adapting sub-layer with its design and complementation, gives the key module into verification, presents the timing sequence modulation result of the whole structure. From the waveform, we can get the conclusion that the overall modules implement the ONU's TC adapting sub-layer's anticipated logic. Finally, creativeness and conclusions are summarized.