Design And Implementation Of Special Packet Switching Unit For Space Station

In recent years,satellite communication technology has developed rapidly,and the amount of traffic to be transmitted by communication satellites has increased day by day.Today's communication satellites do not only play a role of forwarding,but are combined with onboard switching and other technologies to have higher anti-jamming performance and can meet the needs of different users.Therefore,on-board switching technology with high-speed bandwidth transmission,low latency,and low bit error rate has become the main development direction of satellite communications.Combined with the laboratory project "Design and Realization of Special Packet Switching Unit for Space Station",this article carried out a series of researches on the design of on-board switching unit.This article first introduces the research background of the subject and the application and development of on-board switching technology in the aerospace field,and then makes arrangements for the main content of the full text.Next,analyze the requirements of the project,design the overall implementation plan of the special packet switching unit,and divide the functional modules under the plan.Third,the design of each important module under the overall design plan is introduced in detail,including the input and output processing unit,the packet processing unit,the queue management unit,and the dedicated network management control unit.The input and output processing unit is connected with the interface to complete the adaptation and format conversion of the data frame.The packet processing unit completes the search of routing table entries.The queue management unit adopts the structure of 8 priority queues to share the buffer area to complete the buffering and reading of data frames.The dedicated network management control unit has customized a private protocol to communicate with the routing processing unit.Finally,build a simulation verification platform to simulate and verify each function module,test the correctness of each sub-module function,and then perform board-level debugging based on the actual FPGA platform.The final test results show that this design can meet the storage and forwarding requirements of the special packet switching unit of the space station.The innovations of this article are as follows: first,it adopts the parallel packet processing,ten queue management parallel and one queue management priority scheme to meet the design requirements of laser link priority output;second,a private communication protocol is established between the dedicated network management control unit and the routing processing unit to configure table entries in a pure hardware manner;third,in order to prevent the data frame from being confused after checking the table,a 27-bit time mask is added to each data frame in the receiving scheduling module,and finally the data frame is stored in the buffer area according to the time mask.