The Research Of Networking Mechanisms For Micro-satellites Formation

With the development of society, we have been obtaining more and more detection information from space. Scientific missions that satellite system need to take become more and more complex, which leads to increasing the quality and volume of satellite. In addition, the load module of satellite is closely integrated with other subsystems that supports the normal work of load module, and the failure of any module will directly or indirectly affects the normal work of the other modules, and even leads to the overall system loses all functions. As a result, the traditional satellite technology is more and more difficult to meet the application requirements of new period. Under this background, the distributed satellite system has become one of the main development trends of satellite technology in future.In the running process of satellites, the communication system of satellite formation not only undertake a large number of load data, but also effectively transmit control information,such as position, velocity information in real time to ensure the safety of flight and to process various emergencies rapidly. So the traditional TT&C system based on the ground cannot be applied to distributed satellite system. How to establish a reliable communication network and to support real-time, reliable and efficient transmission of all kinds of data are core problems that need urgent solution.For special work scene and missions of DSS, we present a heterogeneous hierarchical wireless network to support real-time control messages and massive payload simultaneously, which includes infranet sub-network for exchanging time-critical control packets, and service sub-network for transmitting high-capacity payload. In order to implement different functions, sub-networks need to adopt different communication protocols, including routing protocol, MAC protocol, PHY technology, and so on. In this article, infranet sub-network adopted wireless Mesh network structure which can provide several transmission paths and increase robustness of the communication network. Service sub-network adopted PMP network structure which can realize high speed and directional data transmission. In addition, in order to more accurately measure the comprehensive performance of the network, this paper presents the new concept about network transmission efficiency. Our simulation results demonstrate that compared with the homogeneous network, the proposed network model imposes an attractive performance and can support the normal work of DSS.