LoRa Low Power Wide Area Network Research Articles

LoRa Communication Using TVWS Frequencies: Range and Data Rate

Low power wide area network (LPWAN) is a wireless communication technology that offers large coverage, low data rates, and low power consumption, making it a suitable choice for the growing Internet of Things and machine-to-machine communication applications. Long range (LoRa), an LPWAN technology, has recently been used in the industrial, scientific and medical (ISM) band for various low-power wireless applications. The coverage and data rate supported by these devices in the ISM band is well-studied in the literature. In this paper, we study the usage of TV white spaces (TVWS) for LoRa transmissions to address the growing spectrum demand. Additionally, the range and data rate of TVWS-based LoRa, for different transmission parameter values using different path-loss models and for various scenarios such as free space, outdoor and indoor are investigated. A path-loss model for TVWS-based LoRa is also proposed and explored, and the evaluations show that TVWS offers a longer range. This range and data rate study would be useful for efficient network planning and system design for TVWS-based LoRa LPWANs.

Body-UAV Near-Ground LoRa Links Through a Mediterranean Forest

LoRa low-power wide-area network protocol has recently gained attention for deploying ad-hoc search and rescue (SaR) systems. They could be empowered by exploiting body-UAV links that enable communications between a body-worn radio and a UAV-mounted one. However, to employ UAVs effectively, knowledge of the signal's propagation in the environment is required. Otherwise, communications and localization could be hindered. The radio range, the packet delivery ratio (PDR), and the large- and small-scale fading of body-UAV LoRa links at 868 MHz when the radio wearer is in a Mediterranean forest are here characterized for the first time with a near-ground UAV having a maximum flying height of 30 m. A log-distance model accounting for the body shadowing and the wearer's movements is derived. Over the full LoRa radio range of about 600 m, the new model predicts the path loss (PL) better than the state-of-the-art ones, with a reduction of the median error even by 10 dB. The observed small-scale fading is severe and follows a Nakagami-m distribution. Extensions of the model for similar scenarios can be drawn through appropriate corrective factors.

HEURISTIC GATEWAY PLACEMENT FOR MINIMAL TRANSMISSION POWER & COLLISION PROBABILITY IN AN INTERNET OF THINGS LOW POWER WIDE AREA NETWORK (HGPMTPIoT-LPWAN)

A variety of long-range (LoRa), low-power, and low bit-rate wireless network technologies have been made possible by the Internet of Things' (IoT) rapid growth. As a radio technology for the implementation of numerous Internet of Things applications, the LoRa low-power wide area network (LPWAN) has gained prominence. LoRa is frequently used in conjunction with the Long-Range Wide Area Network Media Access Control (LoRaWAN MAC) protocol and functions in the Industrial, Scientific, and Medical (ISM) bands, which are unlicensed. As a result of receiving a wide variety of different message sizes from diverse applications, LoRa networks experience scalability issues when the number of end nodes connected to one network is more than the shared number of channels. This results in collisions and packet loss. In this paper, heuristic gateway placement for minimal transmission power & collision probability in an internet of things low power wide area network (HGPMTPIOT-LPWAN) is proposed to increase network efficiency, and improve overall performance by measuring collision probability, which in turn can help to reduce the need for retransmissions and packet drop rate. The things network simulator is used to measure the collisions and packet drop rate. An improved performance for HGPMTPIOT as against the efficient graph-based gateway placement (EGBGP) for large-scale LoRaWAN deployments is achieved for packet drop rate by 6%. Likewise, the simulation results show improvements in terms of decreasing the collision probability for 20 to 60 nodes by 20%.

Measurement Management System Using LoRa, Sensor Node, and Cloud Platform

With the recent Fourth Industrial Revolution, communication and sensor fields are developing remarkably. Among them, LoRa low-power wide-area network (LPWAN) uses low-power Internet-of-things-only technology, which is cheaper than the existing long-term evolution network, and it is a communication technology that provides wider coverage than short-range communication methods (such as Bluetooth, WiFi, and Zigbee). In this study, a measurement management system was developed using LoRa LPWAN communication. It was constructed as a hybrid measurement system using public and private networks for the ground and underground sections, respectively. We developed a sensor node that could process unique signals by selecting sensors suitable for each mechanism and an integrated monitoring program that could store raw data in the Cloud Platform. The results showed that the communication success rate was 90% for the first transmission and reception and 99% for the second transmission and reception. It was confirmed that the measured values at the sensor and when communication was completed after connecting the sensor node were equal.

Smart Public Lighting Control and Measurement System Using LoRa Network

The installation of smart meters in smart cities to monitor streetlights (SLs) provides easy access to measurements of electrical variables and lighting levels, which improves the operation of installation. The use of smart meters in cities requires temporary high-resolution data to improve the energy efficiency (EE) of SLs. Long range (LoRa) is an ideal wireless protocol for use in smart cities due to its low energy consumption, secure communications, and long range indoors and outdoors. For this purpose, we developed a low-cost new system and successfully evaluated it by developing three devices, namely the measure and control device for street lights (MCDSL), lighting level measurement device (LLMD) and gateway LoRa network (GWLN), based on the Arduino open-source electronic platform. This paper describes the hardware and software design and its implementation. Further, an algorithm has been developed to enhance the energy efficiency of public lights using MCDSL, the energy efficiency for street lights (EESL) algorithm, that use the illumination level measured on the same set of SLs with a dynamic control, which assumed different lighting levels throughout the night, and adjusted luminous flux based on the traffic intensity of pedestrians. It sends the acquired data through the LoRa low-power wide-area-network (LPWAN) to the cloud.

An IoT Architecture for Continuous Livestock Monitoring Using LoRa LPWAN

The Internet of Things (IoT) architecture is quickly becoming popular even outside of its originating scenario of home automation. This paper reports the design, implementation, and performance of an IoT hardware and software architecture conceived for the continuous monitoring of livestock located in barns and during grazing. We have adopted the LoRa low power wide area network (LPWAN) technology to cover the diverse environments, and a suitable configuration of web services to perform data storage, analysis, and visualization. Since the LoRa LPWAN (LoRaWAN) medium access control (MAC) layer does not provide a listen-before-talk (LBT) mechanism, we propose a custom MAC layer with LBT-based carrier-sense multiple access with collision avoidance (CSMA/CA). The devised system has been implemented using off-the-shelf hardware, and its performance has also been estimated with the help of a C++ event-based simulator. The preliminary results of our HW implementation on the field confirm the stability of the conceived system and its reliability.

Monitoring of the Efficiency and Conditions of Induction Motor Operations by Smart Meter Prototype Based on a LoRa Wireless Network

The installation of smart meters in the industry to monitor induction motors (IMs) provides easy access to the measurements of the electrical and mechanical variables, which improves the installation process. Using smart meters in industry requires temporary high-resolution data to improve the energy efficiency (EE) and power factor (PF) of IMs. For these purposes, Long Range (LoRa) is an ideal wireless protocol for the usage in industries due to its low energy consumption. In addition, it provides secure communications and long range indoors and outdoors. LoRa avoids the need to install antennas or routers to extend coverage, as each gateway can service 300 LoRa devices with distances of up to 10 km. For this purpose, this research successfully developed a new prototype for a low-cost IM Efficiency Monitoring System using LoRa (IMEMSL). IMEMSL is based on the Arduino open-source electronic platform. It sends the acquired data through the LoRa low-power wide-area-network (LPWAN) and cloud access gateway. This document describes the hardware and software design and implementation. The experimental results are presented and discussed. Received Signal Strength Indicator (RSSI) and time on air measured endorse the use of LoRa for this type of meters. The approximate cost of the prototype was €72 and €93 for the versions without and with Global Positioning System (GPS), respectively.

A Low Power IoT Sensor Node Architecture for Waste Management Within Smart Cities Context.

This paper focuses on the realization of an Internet of Things (IoT) architecture to optimize waste management in the context of Smart Cities. In particular, a novel typology of sensor node based on the use of low cost and low power components is described. This node is provided with a single-chip microcontroller, a sensor able to measure the filling level of trash bins using ultrasounds and a data transmission module based on the LoRa LPWAN (Low Power Wide Area Network) technology. Together with the node, a minimal network architecture was designed, based on a LoRa gateway, with the purpose of testing the IoT node performances. Especially, the paper analyzes in detail the node architecture, focusing on the energy saving technologies and policies, with the purpose of extending the batteries lifetime by reducing power consumption, through hardware and software optimization. Tests on sensor and radio module effectiveness are also presented.

Performance of a low-power wide-area network based on LoRa technology: Doppler robustness, scalability, and coverage

The article provides an analysis and reports experimental validation of the various performance metrics of the LoRa low-power wide-area network technology. The LoRa modulation is based on chirp spread spectrum, which enables use of low-quality oscillators in the end device, and to make the synchronization faster and more reliable. Moreover, LoRa technology provides over 150 dB link budget, providing good coverage. Therefore, LoRa seems to be quite a promising option for implementing communication in many diverse Internet of Things applications. In this article, we first briefly overview the specifics of the LoRa technology and analyze the scalability of the LoRa wide-area network. Then, we introduce setups of the performance measurements. The results show that using the transmit power of 14 dBm and the highest spreading factor of 12, more than 60% of the packets are received from the distance of 30 km on water. With the same configuration, we measured the performance of LoRa communication in mobile scenarios. The presented results reveal that at around 40 km/h, the communication performance gets worse, because duration of the LoRa-modulated symbol exceeds coherence time. However, it is expected that communication link is more reliable when lower spreading factors are used.

Evaluation of LoRa LPWAN Technology for Indoor Remote Health and Wellbeing Monitoring

Long lifetime of a wireless sensor/actuator node, low transceiver chip cost and large coverage area are the main characteristics of the low power wide area network (LPWAN) technologies. These targets correlate well with the requirements imposed by the health and wellbeing applications of the digital age. Therefore, LPWANs can found their niche among traditional short range technologies for wireless body area networks, such as ZigBee, Bluetooth and ultra wideband. To check this hypothesis, in this work we investigate the indoor performance with one of the LPWAN technologies, named LoRa, by the means of empirical measurements. The measurements were conducted using the commercially available devices in the main campus of the University of Oulu, Finland. In order to obtain the comprehensive picture, the experiments were executed for the sensor nodes operating with various physical layer settings, i.e., using the different spreading factors, bandwidths and transmit powers. The obtained results indicate that with the largest spreading factor of 12 and 14 dBm transmit power, the whole campus area (570 m North to South and over 320 m East to West) can be covered by a single base station. The average measured packet success delivery ratio for this case was 96.7%, even with no acknowledgements and retransmissions used. The campus was covered also with lower spreading factors with 2 dBm transmit power, but considerably more packets were lost. For example with spreading factor 8, 13.1% of the transmitted packets were lost. Aside of this, we have investigated the power consumption of the LoRa compliant transceiver with different physical layer settings. The experiments conducted using the specially designed module show that based on the settings used, the amount of energy for sending the same amount of data may differ up to 200-fold. This calls for efficient selection of the communication mode to be used by the energy restricted devices and emphasizes the importance of enabling adaptive data rate control.