Research Of Testing Techniques Of Interoperability Based On Railway Optical Transport Network (OTN)

ABSTRACT:Optical Transport Network (OTN) is the new generation of" digital transmission system" and " optical transmission system",it is coded by a series of ITU-T recommendation, such as G.872、G.709、G.798. The main advantage of OTN is its full backward compatibility. On the basis of the existing SONET/SDH management functions, OTN can not only provide transparent transmission for existing communication protocols, but also provide end-end connectivity and networking ability for WDM.The problems of wavelength/sub-wavelength service scheduling capabilities, weak networking, weak protection and other issues for the traditional WDM system can also be resolved by OTN. OTN technology inherits the dual advantages of SDH and WDM, its key technical features are as follows:a variety of client signals packaging and transparent transmission, the flexible cross and configuration for larger particles of business, the powerful overhead and maintenance management ability, the enhanced networking and protection function.Around the research project "Research of signal application and maintenance technology---the application of optical transmission in railway network and the research of interconnection technology ", the following aspects are emphasisly elaborated in this paper:1. The frame structure of OTN, the mapping and the package, the OTN multiplexing equipment and OTN technology are introduced in this paper. The advantages and disadvantages between OTN technology and other optical transmission technologies are also compared in the paper;2. The testing program of10Gbps long haul transmission and the testing program of multi-vendor interoperability based on different OTN equipment are described in this paper;3. the transmission performances (optical amplifier、dispersion compensation、 nonlinear effects and OSNR) of single-span(160km) and multi-span(3×120km) based on the rate of lOGbps are elaborated in this paper. By building the actual testing environment and analysizing the datas, the important parameters can be tested and verified. In addition, Only EDFA amplifiers can be used for these systems;4. The interoperability of multi-vendor OTN equipments based on the rate of lOGbps is elaborated in the paper. Since the relevant series of OTN standards has not been defined based on packaging format of Ethernet services, some corresponding problems are brought about in interconnection process. Mapping and slot order inconsistency can lead to interconnection failing. By presenting its specific testing program and building actual environment, the results will be analysed and some feasible advices will be proposed in the paper.Interconnection technology is one of the key issues of OTN networking, and it’s also one of the research hotspots.The research results of this paper will have some reference value and theoretical significance for optical transmission network optimization and network interoperability.