Streaming Transfer Model and Forward Scheme for Satellite Opportunistic Network

In the satellite communication, radio frequency power of satellites is limited, and the links of inter-satellite and satellite-ground have the characteristics of frequent switching, long delay and packet loss. The lack of reliable, fixed and pre-designed connections makes the satellite network have the typical features of opportunistic network, especially in the transmission procedure of large volume data streaming. In order to select the appropriate single-hop forwarding node to reduce the delay and energy efficiency, this paper proposes a novel streaming transfer model based on the time-space topology, to describe the dynamic delay and power changes of the link in satellite opportunistic network. Moreover, a novel forwarding scheme based on link stability function (LSF) is proposed, and the appropriate single-hop forwarding node is obtained by solving a dynamic programming problem under the constraints of delay and energy. We choose the Earth-to-Moon communication as the simulation scenario, and utilize STK and MATLAB to analyze the visibility and data volume among the forwarding nodes in the network. The simulation results demonstrate that the LSF scheme decreases energy consumption by 3% and delay by more than 20%, compared with the random unicast scheme, which can significantly improve the transmission efficiency of streaming files in satellite opportunistic networks.