198 research outputs found

    Interference Measurements in the European 868 MHz ISM Band with Focus on LoRa and SigFox

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    Performance of a live multi-gateway LoRaWAN and interference measurement across indoor and outdoor localities

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    Little work has been reported on the magnitude and impact of interference with the performance of Internet of Things (IoT) applications operated by Long-Range Wide-Area Network (LoRaWAN) in the unlicensed 868 MHz Industrial, Scientific, and Medical (ISM) band. The propagation performance and signal activity measurement of such technologies can give many insights to effectively build long-range wireless communications in a Non-Line of Sight (NLOS) environment. In this paper, the performance of a live multi-gateway in indoor office site in Glasgow city was analysed in 26 days of traffic measurement. The indoor network performances were compared to similar performance measurements from outdoor LoRaWAN test traffic generated across Glasgow Central Business District (CBD) and elsewhere on the same LoRaWAN. The results revealed 99.95% packet transfer success on the first attempt in the indoor site compared to 95.7% at the external site. The analysis shows that interference is attributed to nearly 50 X greater LoRaWAN outdoor packet loss than indoor. The interference measurement results showed a 13.2–97.3% and 4.8–54% probability of interfering signals, respectively, in the mandatory Long-Range (LoRa) uplink and downlink channels, capable of limiting LoRa coverage in some areas

    Limitations of current LP-WAN systems

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    LP-WAN systems are important components of the IoT. They allow the exchange of small amount of data over long distances with relatively little energy and little infrastructure complexity. These important characteristics have led to great interest. They have also led to legitimate application and market dreams. As is often the case with new technologies, there are misunderstandings that can result in disappointments if the limitations of the technologies are not properly understood. In this work, we highlight some of those restrictions, looking especially (but not only) at aspects such as energy, throughput and determinism. We draw on our own practical experiences and measurements, as well as works done by other groups

    Coverage and Capacity Analysis of Sigfox, LoRa, GPRS, and NB-IoT

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    Grant-free Radio Access IoT Networks: Scalability Analysis in Coexistence Scenarios

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    IoT networks with grant-free radio access, like SigFox and LoRa, offer low-cost durable communications over unlicensed band. These networks are becoming more and more popular due to the ever-increasing need for ultra durable, in terms of battery lifetime, IoT networks. Most studies evaluate the system performance assuming single radio access technology deployment. In this paper, we study the impact of coexisting competing radio access technologies on the system performance. Considering \mathpzc K technologies, defined by time and frequency activity factors, bandwidth, and power, which share a set of radio resources, we derive closed-form expressions for the successful transmission probability, expected battery lifetime, and experienced delay as a function of distance to the serving access point. Our analytical model, which is validated by simulation results, provides a tool to evaluate the coexistence scenarios and analyze how introduction of a new coexisting technology may degrade the system performance in terms of success probability and battery lifetime. We further investigate solutions in which this destructive effect could be compensated, e.g., by densifying the network to a certain extent and utilizing joint reception
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