An in-vehicle wireless terminal is disclosed. The in-vehicle wireless terminal includes a disconnection detection section for detecting whether an antenna is disconnected, and a determination section for determining whether the vehicle is located within a predetermined distance from a wireless base station. The in-vehicle wireless terminal further includes a control section configured to set transmission power to a maximum value to perform data transmission to the wireless base station if the disconnection detection section detects that the antenna is disconnected and if the determination section determines that the vehicle is located within the predetermined distance from the wireless base station.