Abstract: Aiming at the applied background of low-orbit Walker constellation, a complete satellite network communication system architecture based on a hierarchical clustering routing protocol is proposed, which covers the network layer, data link layer and physical layer. For ease of analysis, a typical model of low-orbit Walker constellation is built firstly. The topological characteristics and the communication visibility between satellites with different orbital phase factors and orbit inclination are analyzed. Then a concept called Virtual Same Orbit is proposed in the paper based on the constellation topology, and a double layer network is built according to the Virtual Same Orbit. Finally, for this double-layer network, the specific schemes are given in the network layer, data link layer and physical layer respectively to achieve information interaction between same-orbit and different-orbit satellites. The communication protocol stack designed in this paper considers the cross-orbit information transmission scheduling problem of Walker constellation, taking into account the transmission efficiency and design complexity, which has certain reference value for the design of other Walker constellation inter-satellite networking systems with similar configurations.

Key words: walker constellation, inter-satellite communication, hierarchical clustering, virtual same orbit