The Design Of Proximity-1 Space Link Protocol

With the rapid development of the space exploring, it is more and more urgent for people to explore the space. The successful launching of Shenzhou-5 marks the great step of Chinese space exploring. But there is still large gap between China and the world's advanced level and also it can not comply with modernization. Based on the need for modernization and long goal, our country is establishing the plan for 21st century's space exploring. We will make the space exploring quick to meet the need for the country economy and national defense. And we must keep the leadership of the world. After we successfully launched man-carrier space shuttle, we have new need for space exploring.In recent year many countries have began to explore the space. It's very important for the countries to work together to save manpower and material resources. This paper mainly designs the Proximity Link System. The system is used in data relaying in the space exploring. It can be used in many space tasks, such as our country's exploring moon and exploring Mars in the future.The Proximity Link project will take three steps. The first step is to realize the point to point full duplex or half full duplex communication. The second step is to realize the communication network between many points. The last step is adding telemetry and navigation based on the second step. This paper mainly discusses the first step. First, I give the whole systems of Proximity Link by referring to the civil and abroad literature. Then I introduce the concepts about level design and make the frame structure of the Proximity Link Protocol. I also analyze the physical layer, data link layer and the progress of the protocol, etc. Then I introduce the algorithm of automatic repeat request and calculate the utilization ratio of the link. At last I make proximity link protocol simulations under some usual conditions.