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1IntroductionWhile the standardization on device-to-device (D2D) communications is underway within 3GPP [1] and IEEE802 [2], various research eorts are being made to develop D2D which is regarded as a component of the heterogeneous network [3]–[6]. Research is being conducted to develop D2D communication systems that leverage existing infra-structure, including a part of cellular networks [4][5], and autonomous D2D communication systems, such as a peer aware communication (PAC) network [6]. Direct com-munications between devices may reduce wireless network load, including that in cellular networks, and increase communication speed between transmission and reception antennas. In addition, they are useful in increasing throughput in hotspots. Furthermore, research is being conducted on the role of D2D communications in IoT and mobile social networks [7][8].We developed D2D communication network testbeds by focusing on areas where community buses are operated to facilitate local information sharing by the public using a broadcasting mode as a basic communication technique [9][10]. With the collaboration of Minato City, Tokyo and Seika Town, Kyoto, we set up our testbeds in these areas and carried out demonstration experiments there from 2014. e testbeds included the Odaiba Rainbow Bus, a community bus service run by Minato City, the Seika Kururin Bus, a community bus service run by Seika Town, and the routes of these bus services. Information was transmitted between communication devices installed in buses and communication devices within the test terminals installed along the bus routes while the buses were in op-eration. A variety of community-related information, such as local government information and event announce-ments, was collected and diused in these experiments. We later added redundancy to the testbed in Seika Town, en-2-7 Development and Field Trial of D2D Networks for Local Area Information Collection and DistributionHuan-Bang LI, Lin SHAN, Ryu MIURA, Takashi MATSUDA, Fumihide KOJIMA, Yasunori OWADA, and Masugi INOUENICT has developed a testbed of device-to-device communication networks for the purposes of information collection and distribution among local communities. With the cooperation of local administrations, the testbed was deployed in the Odaiba area of Minato City of Tokyo as well as in Seika Town of Kyoto, respectively, in 2014. The Odaiba area and Seika Town are respectively used as a typical urban model and a typical rural model. All devices of the testbed are installed at 920 MHz frequency band. On one hand, various devices of the testbed are installed in the community buses including ‘Odaiba Rainbow Buses’ operated by Minato City as well as ‘Seika Kururin Buses’ operated by Seika Town. On the other hand, devices of the testbed are deployed in the surroundings of bus routes. Various experiments have been being conducted since then. None of devices performs central coordination in the testbed. Devices communicate each other autonomously when they are within communication range. Consequently, any single device doesn’t have dominant effect to the entire network. Such features enable robust communication networks during emergency situation such as disasters. Devices installed in buses communicate with surrounding devices anywhere within range and exchange information each other, so that local area information are collected and distributed as buses move. Moreover, by receiving the location information sent from the running buses across all bus routes, we construct a bus location guidance system. The developed device-to-device communication networks for information sharing at local community are independent from cellular and other existing wireless networks and various applications can be expected.432 Terrestrial Communication Technology Research and Development