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e government’s “Robot Revolution Realization Conference” released in January 2015 the “New Robot Strategies.” In addition, from the standpoint of the legal system, enhancement was developed; in December 2015, the amended Civil Aviation Act, which has unmanned aerial vehicle-related articles, was eectuated. So, we have had a roadmap for the growth of industries, which covers the matters of technology development and the matters of environment improvement.On the other hand, because a drone’s essential feature is ying freely in 3D space, wireless means are indispens-able for their control and status acquisition. So, another important issue, for the safety enhancement and the growth of acceptance of drones, is how to improve the reliability and user friendliness of the wireless systems. However, the wireless systems currently used in business operations are extension models of hobby-use systems (for radio-control planes)—although inexpensive and easy to handle—which have drawbacks in reliability as follows: the wireless range is short and it is susceptible to wave shielding by obstacles or electromagnetic interference; once the aircra goes out of wireless range, we have no aircra guidance means other than full automatic cruising mode (autopilot mode) where we are unable to override control of the aircra. We have, through conducting drones operations, accumulated a variety of wireless technologies and knowhow on drone operation. By utilizing those experiences and knowhow, we successfully developed the following technologies and proved their validity through experiments: technologies for controlling drones—including the multi-rotor type—in places beyond line-of-sight, from where radio waves do not directly reach the drone; and technologies for securing safe simultaneous cruising of a number of drones belonging to dierent operators through having each drone share others’ location information.Along with the activities just mentioned, we have contributed to the eorts of standardization by interna-tional organizations including the International Civil Aviation Organization (ICAO) and the Asia Pacic Telecommunity Wireless Group (AWG). Also, we have assisted the Ministry of Internal Aairs and Communication in their activities for frequency allocation to robots (un-manned ying objects), which is the rst business opera-tion-oriented frequency allocation in licensed bands for drones in Japan.In this article, we are presenting our activities starting with the rst-in-Japan deployments and operations of drones to the recent achievements.2Developments and experiments of wireless link systems for avoiding communication blackout in disaster situations2.1Generals on systemsWe developed a wireless link system[2] consisting of ground stations and small lightweight link units mounted on drones to work as a “ying radio tower” for the purpose of avoiding temporary and local area communication blackouts in the wake of a disaster (Fig. 1), based on the studies on the incidents that occurred in the Great East Japan Earthquake in March 2011 where communication infrastructures suered extremely severe damages causing information-isolation of local communities or shelters. In 2012, we introduced three Puma AEs [1]—a type of un-manned small xed wing aircra—to mount our system on them.e system wirelessly links two separated points on the ground, avoiding interference from mountains or buildings on the ground, using a drone circling around a xed point in the air at an altitude of several hundred meters. Moreover, by applying a two-plane air relay via plane-to-plane wire-less link, the system is able to link two points of far distance (Fig. 2).e wireless link unit we developed has the congura-tion and characteristics as follows: the unit is mountable, with the batteries exclusively used by the unit, in an aircra payload space of about 10cm wide;the weight of the unit is around 500 grams including batteries;the unit is operated in the 2 GHz band (with experi-ment radio station license);its output power is 2 W;it uses MSK modulation;FiF1Puma AE (introduced drone), drone mountable communication unit and ground station (developed)2 Terrestrial Communication Technology Research and Development58　　　Journal of the National Institute of Information and Communications Technology Vol. 64 No. 2 (2017)