In this paper, we consider the problem of using flying robots to provide internet service to mobile users. Two important aspects are accounted in this context: the robot deployment problem and the relocation problem. Where to deploy the flying robots directly influences the user coverage and the quality of service, and the relocation problem looks for an efficient scheme to relocate the flying robots such that the total moving distance is minimized, with the aim of saving the previous energy resource preloaded on the flying robots. We formulate these two problems and show that the drone deployment problem is a NP-hard problem. Then, we propose a heuristic algorithm to address it. For the relocation problem, we formulate it as the conventional assignment problem and use a liner programming algorithm to solve it. We conduct extensive computer simulations to demonstrate the effectiveness of the proposed approaches.