Research And Transaction Of Digital Wrapper' Overhead On OTN

Along with the development of optical communication technique and fiber technology, Optical Transport Network(OTN) plays a critical role in the modern information society. It is a very important academic topic that how to manage the Optical Transport Network with a cost-effective way. So far , there is not a generally management standards accepted by the industry of OTN. Based on the current development state of OTN, The International Telecommunication Union (ITU-T) proposed G.709, Digital Wrapper is the core of this protocol.Digital Wrapper is a management technology of OTN, this advanced technology can envelope the primary signal without any change of bit rate, frame structure and timing of client layer signal, therefore it supports all client signal which transmit in OTN. It become more complex that management based on service when transmitting more signal on same fiber. To redistribute routing or fault recovery, the network must be able to monitor every service channel. Digital Wrapper is one of the management methods on optical channel (OCh) with the ability of OAM (Operation, Administration, Maintenance) and the capacity of monitoring optical channel. There is rich overhead bytes in OTN frame that uses Digital Wrapper. It is a main topic how to extracted those overhead bytes from OTN frame uses Digital Wrapper or inserted them into the frame real-timely and effectively in OTN. Due to the development of advanced tools of EDA(Electronic Design Automation) ,we do not need more expertise about hardware circuit for FPGA design. In addition to the traditional method by hardware logic circuit, we can also use HDL(Hardware Description Language) for FPGA design. As the unique advantage of parallel processing and low delay, FPGA is suitable for ultra-high-speed and real time signal processing. Thus FPGA has a wide range of application in the field of communications.The main research contents and characteristics in this paper are as follow:The comparison between Digital Wrapper and other optical layer managementmethod.Discussion of overhead of Digital Wrapper.Realization of the frame alignment of OTN frame used Digital Wrapper.Realization and optimization of RAM control based on the finite state machine.Time-simulation of overhead processing on Max+plus II.