Gigabit Passive Optical Network Media Access Control Layer Of The Key Technologies Research

In order to achieve optical access network and AON,the research of GPON's key technologies is important.The foundation of this thesis is product R&D of telecommunication equipment provider.we study the development of the standard,considering synthetically some factors including development of optical network, demands of ISP and technique capability.In order to realize commercial GPON system,some key issues must be solved,which include user security, safeguard technologie,TDM manage,GEM encapsulation,ranging, fast outburst synchronization, media access control ,and so on.Here we study three key technologies in MAC layer in GPON, the main content are:(1)It presents an analysis of standard, and suggests that GEM encapsulation should be adopted.(2)It investigates ranging method, which measure the logical distance between each ONU and its associated OLT and determining the transmission timing such that upstream cells sending from different ONUs on the same ODN do not collide.(3)It discusses some dynamic bandwidth allocation algorithms which have been put forward, and point out their advantage and disadvantage.(4)A new dynamic bandwidth allocation algorithm is presented with its support differentiated services over GPON and it follows the standard.(5) A GPON model was developed and implemented on OPNET Modeler, the result validates the capability of new algorithm.