Recently, using mobile gateway(s) as a mechanical data carries emerges as a promising approach to prolong sensor network lifetime and relaying information in partitioned network. These mobile gateways, which move in pre-determined paths, visit the sensors to upload their data. As the sensors data generation rate for different sensors may vary based on their locations, sensors need to be visited at different frequencies. In this paper, we present the problem of scheduling the mobile gateways’ path so that the sensors’ visiting frequencies are satisfactory, and the sensors’ data is uploaded to the sink at least at the frequency they are generated. We also prove that the problem is NP-Hard. In addition to integer linear programming formulation, a practical heuristic is also proposed and its performance is compared against the optimal results