Smart and Very Distant Objects Nikola Jovalekic School of Electrical Engineering, University of Belgrade Belgrade, Serbia jovalekic@gmail.com Ermanno Pietrosemoli Telecommunications/ICT4D Lab, ICTP Trieste, Italy ermanno@ictp.it Marco Rainone Telecommunications/ICT4D Lab, ICTP Trieste, Italy mrainone@libero.it Marco Zennaro Telecommunications/ICT4D Lab, ICTP Trieste, Italy mzennaro@ictp.it ABSTRACT This work addresses the feasibility of extreme long distance links based on LoRa technology. We developed a specialized low-cost and highly sensitive hardware based on the LoRa chipset and deployed it in a 316 km long link. Received signal strength, signal to noise ratio, and packet reception rate were measured at two diferent frequency bands: 434 MHz and 868 MHz. Results clearly show that the link is feasible at both frequencies even with omni directional antennas. In addition, we provide details on the planning of the experiments, as well as procedure employed to fnd the suitable test bed for such a long distance link. These types of wireless systems are quite useful for disaster mitigation applications in sparsely populated areas. CCS CONCEPTS · Hardware → Wireless devices;· Networks → Physical links; KEYWORDS LoRa, extreme long distance, link planning, wireless, IoT, LPWAN, disaster prevention ACM Reference format: Nikola Jovalekic, Ermanno Pietrosemoli, Marco Rainone, and Marco Zen- naro. 2017. Smart and Very Distant Objects. In Proceedings of SmartObjects’17, Snowbird, UT, USA, October 16, 2017, 6 pages. https://doi.org/10.1145/3127502.3127514 1 INTRODUCTION Most work on IoT has been focused in the interconnection of a great number of devices at short distances. Yet there are applications in which very long links are required, for instance in natural disaster prevention and mitigation, specially in developing countries, where the data processing facilities may be far away from the sensor nodes. These applications share the following requirements: (i) nodes must be cheap, since they might be damaged or stolen because of its remote location, (ii) they must consume little power, to be able to operate for long time without maintenance, and (iii) they must be able to operate at long distances, since the gateway might be far away from some of the nodes. While recent analyses have reported more realistic forecasts about the number of devices that will be part of the Internet of Things, the number is still in the billions [3, 7, 13]. Most of the devices will be installed in domestic or industrial environments, since consumer and industrial automation are the two main areas of growth for IoT applications[1, 2, 6, 11]. Consumer devices require widespread, fast and secure wireless connections, so they will focus mostly on WiFi and Bluetooth Low Energy (BLE) so- lutions. Industrial devices are installed in RF noisy environments, so they demand reliable and interference resistant wireless protocols. On the other hand, in natural disaster prevention and mitigation there are many IoT applications in which very long wireless links are required to transmit the sensors outputs to the places where they can be used for decision making. For example, in rivers to detect level and water fow; in forests to detect fres; in volcanoes [17] to detect eruptions often predated by gas emissions, and in mountain slopes to monitor early indications of landslides, avalanches or abnormal quantities of rain. This is especially true in developing countries, where there is ample space for growth of IoT networks, with many applications that require very long links [8]. While the above requirements could be satisfed with the LoRa technology, the existing literature reports ranges of only a few tens of kilometers. Our previous experience in long distance wireless links motivated us to explore the range limits of reliable communication links with LoRa devices. This work presents the hardware optimized for very long dis- tance links that we developed using the Semtech LoRa chipset, and explores the feasibility of an extremely long wireless link of 316 km, yet unreported in peer reviewed literature. We describe each step in the link planning process, and give results for several diferent types of the antennas used in the experiments at two frequency bands: 868 MHz and 434 MHz. 2 LORA AND LONG LINKS LoRa refers to a modulation technology that exploits the well known advantages of spread spectrum techniques to address the needs of low power, long range, wide area networks (LPWAN) using low cost end devices [5, 14]. This is done by leveraging chirp spread spectrum (CSS) modulation, widely used in radar, to build a frequency drift