Outdoor Internet Of Things Research Articles

Intelligent metasurface based antenna with pattern and beam reconfigurability for internet of things applications

The Internet of Things (IoT) devices are distributed randomly in the environment, antennas with multiple switched beams are needed to unlock the full potential of communication systems. This paper presents an intelligent metasurface (IMS) based pattern and beam reconfigurable antenna for indoor as well as outdoor IoT applications including V2X and 5 G Small Cell. The IMS based antenna system consists of a wideband monopole and a programable IMS acting as a reflector. The single–layered metasurface is comprised of 4×4 square ring-shaped unit, where each unit cell can be controlled by a pair of four diodes. Due to the separate control of each unit cell, the shape and size of the reflector can be controlled, resulting in different radiation patterns. The system offers various radiation patterns, starting from omni–directional to broadside, with single or dual beams, along with beam–steering both in elevation and azimuth plane. The antenna system offers a peak gain up to 8.89 dBi with an operational bandwidth of 4.95–7.6 GHz. To validate the design concept, the system is fabricated and tested. A microcontroller is utilized for the switching IMS configuration. The high agreement between simulated and measured results, combined with the low profile, high gain, pattern–beam reconfigurability make the proposed antenna a suitable candidate for the indoor IoT devices along with outdoor application not limited to V2X communication systems as well as for small cell in smart cities.

Estimating the Environmental Impact of Green IoT Deployments.

The Internet of Things (IoT) is demonstrating its huge innovation potential, but at the same time, its spread can induce one of highest environmental impacts caused by the IoT industry. This concern has motivated the rise of a new research area aimed at devising green IoT deployments. Our work falls in this research area by contributing to addressing the problem of assessing the environmental impact of IoT deployments. Specifically, we propose a methodology based on an analytical model to assess the environmental impact of an outdoor IoT deployment powered by solar energy harvesting. The model inputs the specification of the IoT devices that constitute the deployment in terms of the battery, solar panel and electronic components, and it outputs the energy required for the entire life-cycle of the deployment and the waste generated by its disposal. Given an existing IoT deployment, the models also determine a functionally equivalent baseline green solution, which is an ideal configuration with a lower environmental impact than the original solution. We validated the proposed methodology by means of the analysis of a case study conducted over an existing IoT deployment developed within the European project RESCATAME. In particular, by means of the model, we evaluate the impact of the RESCATAME system and assess its impact with respect to its baseline. In a scenario with a 30-year lifespan, the model estimates for the system more than 3 times the energy required by its baseline green solution and a waste for a volume 15 times greater. We also show how the impact of the baseline increases when assuming deployments in locations at increasing latitudes. Finally, the article presents an implementation of the proposed methodology as a web service that is publicly available.

On the Coverage of UAV-Assisted SWIPT Networks With Nonlinear EH Model

Unmanned aerial vehicles (UAVs) with huge-capacity batteries could be employed to wirelessly charge the ground sensor users (GSUs) and enhance the coverage of aerial wireless networks in outdoor Internet of Things (IoT). This paper investigates the information and energy coverage of UAV-enabled simultaneous wireless information and power transfer (SWIPT) networks. Both power splitting (PS) and time switching (TS) receiver architectures are considered. By using stochastic geometry approach, the general and explicit expressions of the information coverage probability (ICP), the energy coverage probability (ECP) and the joint information and energy coverage probability (JIECP) are derived under the nonlinear and linear energy harvesting (EH) models, respectively. Particularly, the Laplace transform and the probability generating functional (PGFL) are used to derive the ICP. And, Campbell’s theorem and the maximum function are applied to obtain the ECP and the JIECP, respectively. To achieve the optimal UAVs’ deployment density, the maximization optimization problems are formulated for the PS-based and TS-based systems, respectively. By using the series expansion of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q(x)$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -function) with large <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> , the closed-form approximating optimal solutions to the formulated problems are obtained. Monte Carlo simulations validate the correction of our obtained theoretical results, and numerical results show that the performance of the PS-based system is superior to that of the TS-based one. Moreover, when the energy requirement of GSUs or the transmit power of UAVs is relatively large, or when the information requirement of GSUs or the UAV deployment density is relatively small, compared with the nonlinear EH model, the analysis bias caused by traditional linear EH model is relatively large and in these cases, traditional linear EH model cannot be used to replace the nonlinear EH one for the system performance analysis or optimal system design.

Rancang Bangun WSN berbasis nRF24L01 dan SIM800l bertenaga Surya untuk Implementasi IoT secara Outdoor

Internet of things (IoT) requires an internet network for data communication between machines. Wifi is not always available outdoors and requires more portable data communication. This study aims to design a prototype Wireless Sensor Network (WSN) based on nRF24L01 and solar-powered SIM800l for outdoor IoT implementation. The study used a total of five IoT devices with four nodes with nRF24L01 and one node with nRF24L01 and SIM800l. Each device uses an Arduino nano, TP4056, 6WP solar panel, and a 900mAh 18650 battery. The evaluation of the system includes a comparative QoS analysis, namely packet delivery ratio (PDR), throughput, and delay in star and bus topology through data collection of observation methods by sensors. The evaluation results show that for unidirectional data communication the star topology has better results with PDR 99,099%, throughput 99.393%, and delay 0.0095s. While the bus topology produces a slight difference in PDR 98.766%, throughput 98.461%, and delay 0.017s. Evaluation of energy availability shows that during the day with an average voltage of 3.703v and at night 2.976v, there is no significant difference. During the day it produces 99.301% PDR, 99.653% throughput, and 0.001s delay, while at night it produces 94.221% PDR, 99.881% throughput, and 0.027s delay.

Feasibility of LoRa for Smart Home Indoor Localization

With the advancement of low-power and low-cost wireless technologies in the past few years, the Internet of Things (IoT) has been growing rapidly in numerous areas of Industry 4.0 and smart homes. With the development of many applications for the IoT, indoor localization, i.e., the capability to determine the physical location of people or devices, has become an important component of smart homes. Various wireless technologies have been used for indoor localization including WiFi, ultra-wideband (UWB), Bluetooth low energy (BLE), radio-frequency identification (RFID), and LoRa. The ability of low-cost long range (LoRa) radios for low-power and long-range communication has made this radio technology a suitable candidate for many indoor and outdoor IoT applications. Additionally, research studies have shown the feasibility of localization with LoRa radios. However, indoor localization with LoRa is not adequately explored at the home level, where the localization area is relatively smaller than offices and corporate buildings. In this study, we first explore the feasibility of ranging with LoRa. Then, we conduct experiments to demonstrate the capability of LoRa for accurate and precise indoor localization in a typical apartment setting. Our experimental results show that LoRa-based indoor localization has an accuracy better than 1.6 m in line-of-sight scenario and 3.2 m in extreme non-line-of-sight scenario with a precision better than 25 cm in all cases, without using any data filtering on the location estimates.

Sub-1 GHz Frequency Band Wireless Coexistence for the Internet of Things

Motivated by the explosion of the Internet of Things (IoT), we examined Sub-1 GHz (frequencies below 1 GHz) band wireless technologies that are essential to enable various IoT applications. IEEE 802.15.4g and IEEE 802.11ah are two wireless technologies developed for outdoor IoT applications such as smart utility, smart city and infrastructure monitoring for which both technologies operate in Sub-1 GHz Bands. Our coexistence simulation of IEEE 802.15.4g and IEEE 802.11ah using standard defined coexistence mechanisms shows serious interference problems due to fundamental protocol differences and channel access parameter differences. Accordingly, we proposed IEEE 802.19.3 Task Group formation to lead the IEEE 802.19.3 standard development of IEEE 802.15.4g and IEEE 802.11ah coexistence in the Sub-1 GHz band. In addition to our coexistence methods contributed to IEEE 802.19.3 standard, we propose a novel Active Carrier Sense based CSMA/CA mechanism for IEEE 802.15.4g to reduce CSMA/CA failure packet discard under interference from IEEE 802.11ah traffic and to keep interoperability with conventional IEEE 802.15.4g CSMA/CA mechanism. Our proposed coexistence techniques can improve fair spectrum sharing between IEEE 802.15.4g and IEEE 802.11ah networks for IoT applications.

Coverage Estimation in Outdoor Heterogeneous Propagation Environments

This paper is on a coverage estimation procedure for the deployment of outdoor Internet of Things (IoT). In the first part of the paper, a data-driven coverage estimation technique is proposed. The estimation technique combines multiple machine-learning-based regression ideas. The proposed technique achieves two purposes. The first purpose is to reduce the bias in the estimated received signal strength arising from estimations performed only on the successfully received packets. The second purpose is to exploit commonality of physical parameters, e.g. antenna-gain, in measurements that are made across multiple propagation environments. It also provides the correct link function for performing a nonlinear regression in our communication systems context. In the second part of the paper, a method to use readily available geographic information system (GIS) data (for classifying geographic areas into various propagation environments) followed by an algorithm for estimating received signal strength (which is motivated by the first part of the paper) is proposed. Together they enable quick and automated estimation of coverage in outdoor environments. It is anticipated that these will lead to faster and more efficient deployment of outdoor Internet of Things.

Scalability analysis of multiple LoRa gateways using stochastic geometry

Low-Power Wide Area Networking (LPWAN) technology offers long-range communication, enabling new types of services for Internet-of-Things (IoT). While LPWAN solutions are proliferating verticals at tremendous pace, little attention has been paid to scalability and performance analysis of such networks. Hence, it is of utmost importance to analyze how well these technologies will scale as the number of connected devices grows in future. Several technologies are associated with LPWANs, but Longe Range WAN (LoRaWAN) is the most adopted LPWAN technology worldwide. It promises ubiquitous connectivity in outdoor IoT applications while keeping network structures and management as simple as possible. Consequently LORAWAN has received a lot of attention in recent time from network providers. In this letter, we first perform the system level outage analysis of a single LoRa gateway by using the chirp spectrum modulation scheme. We then extend our investigation to multiple gateway scenario and show that the coverage probability reduces exponentially when the number of gateways increases due to the presence of more interfering signals from different nodes using the same spreading sequence. We conclude that this fundamental limiting factor is perhaps more significant towards LoRa scalability. Our derivations for co-spreading factor interference found in multiple LoRa gateways enables demand of scalability analysis of such networks.

NB-IoTtalk: A Service Platform for Fast Development of NB-IoT Applications

Narrowband Internet of Things (NB-IoT) is considered as a promising wireless communications technology for Internet of Things (IoT) especially for the outdoor environment. Many outdoor IoT applications involve large numbers of homogeneous NB-IoT devices. It is tedious to specify and accommodate these devices during application development. To resolve this issue, this paper proposes a service platform for fast development of NB-IoT applications called NB-IoTtalk. This platform utilizes a tag mechanism to provide an easy-to-manipulate graphical user interface to accommodate a large number of NB-IoT devices in an application and transparently show them in a visual map. Our approach automatically creates and parses the device profile used to interpret the payload of an NB-IoT message. We then use a smart parking lot application as an example to investigate the event-triggered reporting of NB-IoT in terms of the time-to-live (TTL) report frequency and the outage detection accuracy. This paper provides the guidelines to set the TTL interval for event-triggered NB-IoT applications.

A Dynamic Programming Algorithm for High-Level Task Scheduling in Energy Harvesting IoT

Outdoor Internet of Things (IoT) applications usually exploit energy harvesting systems to guarantee virtually uninterrupted operations. However, the use of energy harvesting poses issues concerning the optimization of the utility of the application while guaranteeing energy neutrality of the devices. In this context, we propose a new dynamic programming algorithm for the optimization of the scheduling of the tasks in IoT devices that harvest energy by means of a solar panel. We show that the problem is NP-hard and that the algorithm finds the optimum solution in a pseudo-polynomial time. Furthermore, we show that the algorithm can be executed with a small overhead on three popular IoT platforms (namely TMote, Raspberry PI, and Arduino) and, by simulation, we show the behavior of the algorithm with different settings and at different conditions of energy production.

Performance Analysis of Dual-Polarized Massive MIMO System with Human-Care IoT Devices for Cellular Networks

The performance analysis of the dual-polarized massive multiple-input multiple-output (MIMO) system with Internet of things (IoT) devices is studied when outdoor human-care IoT devices are connected to a cellular network via a dual-polarized massive MIMO system. The research background of the performance analysis of dual-polarized massive MIMO system with IoT devices is that recently the data usage of outdoor human-care IoT devices has increased. Therefore, the outdoor human-care IoT devices are necessary to connect with 5G cellular networks which can expect 1000 times higher performance compared with 4G cellular networks. Moreover, in order to guarantee the safety of the patient for emergency cases, a human-care Iot device must be connected to cellular networks which offer more stable communication for outdoors compared to short-range communication technologies such as Wi-Fi, Zigbee, and Bluetooth. To analyze the performance of the dual-polarized massive MIMO system for human-care IoT devices, a dual-polarized MIMO spatial channel model (SCM) is proposed which considers depolarization effect between the dual-polarized transmit-antennas and the receive-antennas. The simulation results show that the performance of the dual-polarized massive MIMO system is improved about 16% to 92% for 20 to 150 IoT devices compared to conventional single-polarized massive MIMO system for identical size of the transmit array.

Wearable indoor localisation approach in Internet of Things

Localisation is an essential and important research issue in Internet of Things (IoT). Most localisation schemes focus on outdoor IoT. However, indoor IoT is required in some applications such as target detection and tracking, and emerging smarter healthcare. As such, localisation approaches designed for indoor IoT are necessary. Note that the smarter healthcare emerges at an unprecedented speed while few localisation schemes can be directly exploited for them with accuracy guarantee. In this study, the authors propose a wearable indoor localisation approach to improve the localisation accuracy of previous work. In this approach, the wearable devices embedded into person are used to realise their displacement vector in mobile environments, thus estimating their own locations. In addition, the authors propose a walking prediction mechanism to increase localisation accuracy. The real-world experiment results demonstrate that the proposed approach achieves lower localisation error in various moving speeds.

A privacy-preserving smart parking system using an IoT elliptic curve based security platform

Since the initial visions proposed in the SmartDust project fifteen years ago, Wireless Sensor Networks have seen a tremendous development, leading to the realization of the Internet of Things (IoT). Today, there is a large variety of hardware and software to choose from that is easy to set up and use. Even though there is an increasing number of real-world applications that employ large deployments of IoT devices, the wireless nature of communication in combination with the low-end capabilities of the devices raises security and privacy issues that have not been properly addressed. Considering also that sensor node brands are very different in their capabilities, providing a single solution is very challenging.In this paper we adopt Elliptic Curve Cryptography (ECC) as an attractive alternative to conventional public key cryptography, such as RSA. ECC is an ideal candidate for implementation on constrained devices where the major computational resources, i.e., speed, memory are limited and low-power wireless communication protocols are employed. That is because it attains the same security levels with traditional cryptosystems using smaller parameter sizes. We provide a generic implementation of ECC that runs on different host operating systems, such as Contiki, TinyOS, iSenseOS, ScatterWeb and Arduino. Furthermore, it runs on smartphone platforms such as Android and iPhone and also any linux based systems (e.g., raspberryPi). Our implementation does not contain any platform-specific specializations, allowing a single implementation to run natively on heterogeneous networks.We look into the Smart Parking application domain and provide a solution that protects the privacy of the users by totally avoiding the exchange of confidential information. We also show how to protect a user’s privacy by adapting the tool of zero knowledge proofs (ZKP) with our ECC implementation. We study the performance of our system in an real-world outdoor IoT testbed and analyze the execution time and network overhead for each available hardware platform. Our code is available as open source software and can be used from developers who wish to achieve certain levels of security and privacy in their applications.