In a situation of a wide-area disaster caused by an earthquake, tsunami or flood, not only does traffic get shut-down due to damages to roads, but also, due to communication facility breakdowns or power outages, communication-networks, which we suppose are always available, fall into trouble. As a consequence, a large number of areas lose communication means and become so-called information-communication-isolated areas. In such informationcommunication cut-off situations, we have difficulties in confirming the safety of local residents or knowing what is going on in the disaster area. Consequently, we cannot start relief operations in a timely manner, or grasp what goods are in shortage. For the purpose of preparing for such situation in disasters and promptly establishing emergency communication-links to isolated disaster-areas, we imported a drone system in 2012—in those days, terms or technologies like drone or unmanned aerial vehicle (UAV) were quite new in Japan. The aerial system we introduced was the world’s most advanced type of battery-power fixed-wing small unmanned aircraft having the following features: no runway required to take off; easy to handle and portable; promptly deployable at any time: long flight-time of two hours; and capable of flying in a beyond-line-of-sight environment if the wireless-connection is kept. By mounting a wireless relay equipment on the aircraft, we developed a wirelesslink system working as a “flying radio-tower,” a wireless link system, conducting, in collaboration with local governments or other municipalities nation-widely, proof-ofconcept experiments in simulated disaster situations from the point of disaster-prevention; and at the same time, we have collected and analyzed a variety of data relating to radio-propagation or communication quality in various environments. Small unmanned aircrafts, in these days generally called drones—in particular multi-rotor-types—have become widely used—and at a rapid pace of growth—for hobby-use and business-use, particularly for aerial shooting, infrastructure management jobs, or disaster control operations—to the extent that the use of drones is called the “Industrial Revolution in the Air.,”—and reportedly the drone market size is expected to be 200 billion yen domestically and on the order of 10 trillion yen worldwide in 2022 (in five years from now). 2-9 Wireless Communication Technology for Small Unmanned Aircraft Systems ~Towards the deployment of IoT in the Sky~
Satellite communication can provide effective alternative tools to terrestrial communication systems for in-flight aircrafts and ships navigating off-shore, as well as, more importantly, in the case of large-scale disasters where terrestrial-based mobile phone communications may become severely crippled. Large-volume data communication is in dire need in race-against-time disaster situations for sharing real-time information such as dynamic picture images and topographical data on site. The need for larger communication capacity shows no sign of abating even in normal times, for example, for in-flight entertainment purposes. NICT has been conducting research on the Wideband InterNetworking engineering test and Demonstration Satellite (WINDS)[1]. The project includes a variety of research related to mobile satellite communication such as the development and experimental operation of mobile earth stations mounted on a car [2] and on board a ship [3]. They are equipped with an antenna system capable of automatically detecting and tracking the WINDS satellite for uninterrupted communication during experiment/operation. As a part of the WINDS project, an Aeronautical Earth Station (AES) was developed to research in-flight satellite communication. This report describes an overview of the AES, and the outcomes from flight experiments which were carried out with the earth station on board the aircraft [4]–[6].
The Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology have developed “WINDS,” a communications satellite that enables super-high-speed data communications, in an effort to research and develop advanced information networks based on the Japanese government IT strategy “e-Japan Priority Policy Program [1]–[3]”. An H-IIA rocket carrying WINDS was launched on Feb.23, 2008, at Tanegashima Space Center of JAXA. NICT developed the high-speed network with 622/1,244 Mbit/s using a bent-pipe relay line. The three earth terminals, Large Earth Terminal (LET) at NICT Kashima Space Technology Center and the two Super-high Data Rate Very Small Aperture Terminals (SDR-VSAT), were developed to construct a high-speed network with 622/1,244 Mbit/s. Also, a high-speed burst modem with high-performance FEC using turbo product code (TPC: (128, 120)) for a 622/1,244 Mbit/s dual rate high-speed network terminal was developed. After the launch of WINDS, NICT performed transmission experiments with the 622/1,244 Mbit/s dual rate high-speed burst modem at 622/1,244 Mbit/s, and measured the BER characteristic and the UDP/TCP packet error rate. We also confirmed that the network operates normally as a TDMA satellite communication system in the 622 Mbit/s mode between the three terminals. We also succeeded in transmission experiments with 3D, 4K HDTV using this system. This paper reports the configuration and performance of a 622/1,244 Mbit/s TDMA satellite communication system and the results of 622/1,244 Mbit/s TDMA satellite communication experiments using a highspeed burst modem.
As a network that solves various problems in the current Internet, which has an architecture focused on the Internet Protocol (IP), the new-generation network is one of the future networks for which research and development are being advanced by industry, academia, and the government working together. The New-Generation Network Promotion Forum was organized by industry, academia and the government in November 2007; it has been promoting research and development of the new-generation network. In NICT, to advance research and development of the new-generation network, the New-Generation Network Strategic Headquarters was organized in 2007. It studies this research and development strategy, and at the same time, it has been advancing research and development of the new-generation network as a project under industryacademia-government cooperation. Furthermore, the Network Research Headquarters has been set up as the practical organization advancing this research and development, since the start of NICT’s third medium and longterm target period that began in fiscal 2011. This paper describes the progress of research and development on the new-generation network. Section 2 explains an outline of the new-generation network research and development roadmap, and the technology strategy published from 2008 to 2010. Section 3 describes the new-generation network’s research and development plan and its main results in NICT’s third medium and long-term plan period. 2 Progress and conceptual design of the new-generation network
