Based On The Ccsds Space Network Communication Protocol And Realization

Currently, there is a growing emphasis on exploration in space, thereby speeding up the development of space communications technology. At the same time, the Internet has experienced explosive development. It is a trend for Space Network and Internet in future that integrating the Internet and Space Network to build the Integrated Network World.However, the simple combination of the Space Network and the Internet can not achieve the desired results. Because the two networks have different characteristics, corresponding the underlying protocols supporting data transmission are not the same. Therefore, building an integrated network of world, we need three steps: First, in order to achieve protocol conversion, protocol gateway needs; Second, for the purpose of supporting multiple upper layer applications better, we need to improve shortcomings in existing space protocol that only supports little data types; Third, solving the other problems encountered in the integration of the two network. A typical IP over AOS(Advanced Orbiting Systems) gateway just to meet the first two steps, but for the third step it can not do a very good support.This thesis solves the problems encountered in a typical IP over AOS Gateway, including the Gateway can not provide service protection mechanism and poor performance in transport layer. First, because different types of applications have different importance, different features, so take a different virtual channel. Therefore, the guarantee mechanism of services used in this thesis is carried out for the virtual channel, achieving the capabilities of service protection for the upper layer application data. This service protection mechanism mainly perform flow control for virtual channel, to get reasonable link allocation of virtual channel on the valuable satellite wireless; and when scheduling transmission frame in virtual channel to the physical channel, in accordance with virtual channel priority level determines the importance or priority level of data: the virtual channel which have highest priority schedules to physical channel first for sending. Through the handle of two steps above, thereby leading to both the rational use of bandwidth and priority service for the data which have high priority. In addition, the thesis resolves the problem that directly deploying the TCP protocol to IP over AOS gateway will bring(the lower performance of TCP application in satellite wireless link). The thesis proposed several solutions for the combination of SCPS-TP(Space Communications Protocol Specification Transport Protocol) which CCSDS(Consultative Committee for Space Data Systems) proposed and the typical IP over AOS gateway. Through comparative analysis, choose a simple, appropriate for our project's scenarios and realize it. Meanwhile, problems encountered are analyzed and resolved. In addition, given that not all applications require performance enhancements of TCP transport layer, and not all TCP packets's performance can be enhanced, the paper also proposed a scheme called selective enhancement, which carry out performance enhancements of TCP transport layer only for certain types of data.Finally, on the Ubuntu system, this thesis realize the IP over AOS gateway which have service protection mechanism and selective performance enhancement of transport layer. Also carried out related experiments to verify the feasibility of these two scheme.