The Research Of GPON-ONU And The Design Of GTC Layer Interface

With the rapid development of modern communication network,higher bandwidth of access network is require.Passive optical networks (PON) look very promising due to their bandwidth capacity,especially the GPON, offering unprecedented high bit-rate support while enabling transport of multiple services. GPON carries a two-fold promise of both higher bit rates and higher efficiency when carrying multiple services over the PON. It offers a scalable framing structure from 622Mb/s to 2.5Gb/s,as well as support for asymmetric bit rates,exceptionally high bandwidth utilization for any type of service and standard ITU-T Generic Framing Protocol (GFP) encapsulation of any type of service (both TDM and packet) onto a synchronous transport protocol. But GPON technique is at the underway stage in China,and no mature technologies have come out. Therefore it is necessary and stringent to study GPON techniques. ONU is an important composing of GPON, so to study and design it has the important realism meaning.From the principles of the Passive Optical Network(PON),the thesis analyses the current PON technologies,point out the advantages of GPON.Then describes the composing, work theory, and protocol of GPON,the key is the TC layer architecture,it consists of C/M and OAM plane.It put forwards layered designing idea of GPON-ONU, which divides the ONU into the physical media layer (PMD), transmission convergence layer (GTC) and management control layer (OMCI) ,and proposed the overall design scheme and the main chip Selection on this basis. The core is the research and design of the GTC layer interface for ONU-port, consists of the physical media layer inteface ,user network layer interface, management control layer interface and SDRAM interface.it focus on the software design and simulation verification of network control and SDRAM controller. Finally, creativeness and conclusions are summarized.