A sensor node (101-i) is assumed to be able to execute any one among a first operation by which another sensor node (101) is requested to execute data process and if the request is not accepted the sensor node (101-i) starts executing the data processing after waiting for charging and a second operation by which the sensor node (101-i) starts executing the data processing after waiting for charging, without requesting the data processing to be executed. The sensor node (101-i) compares an expected value of a first time that elapses until execution is started by the sensor node (101-i) or the other sensor node (101) when the first operation is executed, and a second time that elapses until execution is started by the sensor node (101-i) when the second operation is executed. Based on the comparison result, the sensor node (101-i) executes among the first operation and the second operation, the operation for which the time that elapses until execution is started is shorter.