Research On Communication Protocol Of Data Link Layer Of Fractionated Payload

With the rapid development of modern aerospace industry, the demand for space exploration is more and more urgent. But compared with the world’s advanced technology, our country is still far behind in the field of space technology. After the successful launch of Chang E and a series of other lunar probes in our country these years, we have further requirements for the exploration of space technology. In addition, the complexity of future space exploration missions will continue to increase, a single spacecraft work independent will be hard to meet the demands. Based on this situation, we can organize several satellites which are physically disconnected between each other to one system and make them complete one space mission together. Among these system, space probes using One-Master and Multi-Slaves which can functionally equal to one virtual satellite and complete space mission collaboratively are considered as Fractionated Payload.The communication between different payload this thesis involved can adopt Proximity-1 Space Link Protocol recommended by Consultative Committee for Space Data Systems. This protocol is mainly used in space data exploration in the Proximity link transmission systems and is broadly applicable.Proximity-1 Space Link Protocol has already been studied in domestic. To accelerate its application, the author of this thesis has mainly done the following work:(1) Analysis the application scenario of Proximity-1 Space Link Protocol under the communication between different payload. Study the design principles and layered model of the data link layer protocol. Determine the composition of the entire structure of the Proximity link system.(2) Detailed analysis the regulations of the function that every sublayer assumed in the data link layer of this protocol. Establish the frame format of different types of transmission unit and abstract the main algorithm according to the protocol, at last design the work flow chart of the protocol.(3) In view of the complexity of the actual operation of the space link, this thesis use the MOXA serial ports to represent different Fractionated Payloads and use software to simulate the link transmission of communication between different Fractionated Payloads. Using the above method to verify Proximity-1 Space Link Protocol and play a reference role in the actual application of this protocol.In the aspect of implementation, this thesis based on analysis of the contents of the protocol, propose an execute plan and implementation platform to simulate the Data Link Layer of this protocol.