A mobile terminal device includes a wireless communication unit that performs wireless communication with another battery-operated device; and a processor connected to the wireless communication unit, wherein the processor executes a process including: calculating power consumption for each of network configurations that differ in a connection relation between a plurality of devices including the mobile terminal device and the another device, the power consumption consumed by the devices for wireless communication, determining a network configuration having a longest battery duration of the devices, based on the calculated power consumption, and setting a connection between the devices according to the determined network configuration.