Research And Emulation On The Multiplexing Function Of Advanced Orbiting System

Advanced Orbiting Systems(AOS) is a suit of systems and recommendation which is advanced by the Committee for Space Data Systems(CCSDS) to meet the need of complex spacecraft to correspondence the various source multiplicity, the redundant reliability, the high speed which, large capacity, the standardization and the international cooperation demand. Therefore, our country astronautics data system should implement the CCSDS standard, in order to carry on the international cooperation in the future, use resources effectively.In this article, firstly, it analyzed the characteristic of AOS system, its data handling service, the grades of the service, the layered structure, the data unit structure, the data transmission process.Secondly,do deep reseach on the multiplexing function. It is discribeded in details on the idea, concept and the process of realization.Also it proposed several key questions which the multiplexing involves, and find out the effective way to solute these questions. Finally, it programed to implement the multiplexing into two modules-the multiplex module and the demultiplex module.It solved that how to generate the first header pointer correctly,how to support servral data type which is defined in AOS,how to generate fill data when there is no any user data,and how to extract user data from the multiplexing data unit (M_PDU),what has been done has completed definition on the multiplexing function in AOS.It is the theory basis of implemention AOS to grasp the idea, the concept and the standard of the AOS.The multiplexing technology is the core of AOS, undersdanding the idea, concept and the standard of the multiplexing ,simulating its process is very essential and necessary for latter advanced work,and it also provides some effective advice and build solid fundition for realizing multiplxing entity.