Inter-satellite link scheduling and power allocation method for satellite networks

Satellite networks have attracted a lot of attention due to their unique advantages such as wide coverage and high data rate. In particular, the use of inter-satellite links (ISLs) allows multiple satellites to collaborate to provide a wider range of services. However, it is more difficult for the design of ISLs and resource allocation with the increasing number of satellites, which further leads to high network cost. Therefore, this paper aims to design an efficient ISLs establishment scheme and power allocation method to reduce the network cost. First, the network cost optimization problem is formulated as a mixed integer linear programming. Then, with equal power allocation scheme, a Lagrange relaxation method is used to decompose the optimization problem into two subproblems, i.e., routing problem and ISLs establishment problem. Specifically, the optimal routing scheme is equivalent to solving a min-cost max-flow problem of time expanded graph. The ISLs design problem can be directly solved by using branch and bound method in parallel. Moreover, with given routing and ISL scheme, the optimal power allocation is given based on convex optimization theory. Finally, the simulation results have be provided for verifying the effectiveness of proposed algorithm.