Long-range Wireless Research Articles

On the global dynamics of connected vehicle systems

In this contribution, heterogeneous connected vehicle systems, that include human-driven as well as connected automated vehicles, are investigated. The reaction time delay of human drivers as well as the communication and actuation delays of connected automated vehicles is incorporated in the model. Saturations due to the speed limit and limited acceleration capabilities of the vehicles are also taken into account. The arising nonlinear delayed system is studied using analytical and numerical bifurcation analysis. Stability analysis is used to identify regions in parameter space where oscillations arise due to loss of linear stability of the equilibrium. Moreover, with the help of numerical continuation, bistability between the equilibrium and oscillations is shown to exist due to the presence of an isola. It is demonstrated that utilizing long-range wireless vehicle-to-vehicle communication the connected automated vehicle is able to eliminate the oscillations and keep the traffic flow smooth.

A Heterogeneous IoV Architecture for Data Forwarding in Vehicle to Infrastructure Communication

The Internet of vehicles (IoV) is a newly emerged wave that converges Internet of things (IoT) into vehicular networks to benefit from ubiquitous Internet connectivity. Despite various research efforts, vehicular networks are still striving to achieve higher data rate, seamless connectivity, scalability, security, and improved quality of service, which are the key enablers for IoV. It becomes even more critical to investigate novel design architectures to accomplish efficient and reliable data forwarding when it comes to handling the emergency communication infrastructure in the presence of natural epidemics. The article proposes a heterogeneous network architecture incorporating multiple wireless interfaces (e.g., wireless access in vehicular environment (WAVE), long-range wireless fidelity (WiFi), and fourth generation/long-term evolution (4G/LTE)) installed on the on-board units, exploiting the radio over fiber approach to establish a context-aware network connectivity. This heterogeneous network architecture attempts to meet the requirements of pervasive connectivity for vehicular ad hoc networks (VANETs) to make them scalable and adaptable for IoV supporting a range of emergency services. The architecture employs the Best Interface Selection (BIS) algorithm to always ensure reliable communication through the best available wireless interface to support seamless connectivity required for efficient data forwarding in vehicle to infrastructure (V2I) communication successfully avoiding the single point of failure. Moreover, the simulation results clearly argue about the suitability of the proposed architecture in IoV environment coping with different types of applications against individual wireless technologies.

Optimal Resonant Beam Charging for Electronic Vehicles in Internet of Intelligent Vehicles

To enable electric vehicles (EVs) to access to the Internet of Intelligent Vehicles (IoIV), charging EVs wirelessly anytime and anywhere becomes an urgent need. The resonant beam charging (RBC) technology can provide high-power and long-range wireless energy for EVs. However, the RBC system is unefficient. To improve the RBC power transmission efficiency, the adaptive RBC (ARBC) technology was introduced. In this paper, after analyzing the modular model of the ARBC system, we obtain the closed-form formula of the end-to-end power transmission efficiency. Then, we prove that the optimal power transmission efficiency uniquely exists. Moreover, we analyze the relationships among the optimal power transmission efficiency, the source power, the output power, and the beam transmission efficiency, which provide the guidelines for the optimal ARBC system design and implementation. Hence, perpetual energy can be supplied to EVs in IoIV virtually.

Long-Range Wireless Tethering Selfie Camera System Using Wireless Sensor Networks

This paper proposes a wireless sensor network (WSN)-based long-range wireless tethering system (WSN-SELFIE) that implements the novel GIGA-SELFIE system that can take selfies and landscape photos from long distances. In WSN-SELFIE, a low-power WSN using radio frequency (RF) transceiver modules is used to provide long-range communication between a camera and a sensor node. The operating range of WSN-SELFIE can be extended easily by adding more relay nodes to the network. The experimental results demonstrate that WSN-SELFIE performs efficiently in terms of network range, end-to-end network delay, and processing time. Furthermore, it outperforms commercial photography drones and GIGA-SELFIE in terms of cost and runtime.

An Analytical Model of the Small World Effect in D2D Wireless Networks

Small-world networks are characterized by large clustering coefficients and small characteristic path lengths. These properties are induced by replacing a small fraction of short-range local scale links of a geometric/Euclidean graph with long-range global scale links. Advances in wireless networks allow for cost-efficient addition of secondary long-range wireless interfaces in devices. We derive analytical mean-field solutions for 1) clustering coefficient and 2) characteristic path length of peer-to-peer D2D wireless networks with topologies mimicking small-world networks. In graph-theoretic terms these topologies correspond to geometric graphs of randomly deployed nodes in two-dimensions with range limited shortcuts. The models show that in spite of the fact that links used to create shortcuts are range limited, the network still retains the essential phase difference between characteristic path length and clustering coefficient that is the hallmark of small-world networks when a small fraction of all nodes, as little as 1%–5%, have range limited shortcut links. We also demonstrate the utility of these models as design tools for determining deployment parameters of small-world wireless sensor networks.

Design and Analysis of Adaptive Hierarchical Low-Power Long-Range Networks

A new phase of evolution of Machine-to-Machine (M2M) communication has started where vertical Internet of Things (IoT) deployments dedicated to a single application domain gradually change to multi-purpose IoT infrastructures that service different applications across multiple industries. New networking technologies are being deployed operating over sub-GHz frequency bands that enable multi-tenant connectivity over long distances and increase network capacity by enforcing low transmission rates to increase network capacity. Such networking technologies allow cloud-based platforms to be connected with large numbers of IoT devices deployed several kilometres from the edges of the network. Despite the rapid uptake of Long-power Wide-area Networks (LPWANs), it remains unclear how to organize the wireless sensor network in a scaleable and adaptive way. This paper introduces a hierarchical communication scheme that utilizes the new capabilities of Long-Range Wireless Sensor Networking technologies by combining them with broadly used 802.11.4-based low-range low-power technologies. The design of the hierarchical scheme is presented in detail along with the technical details on the implementation in real-world hardware platforms. A platform-agnostic software firmware is produced that is evaluated in real-world large-scale testbeds. The performance of the networking scheme is evaluated through a series of experimental scenarios that generate environments with varying channel quality, failing nodes, and mobile nodes. The performance is evaluated in terms of the overall time required to organize the network and setup a hierarchy, the energy consumption and the overall lifetime of the network, as well as the ability to adapt to channel failures. The experimental analysis indicate that the combination of long-range and short-range networking technologies can lead to scalable solutions that can service concurrently multiple applications.

Energy Harvesting in LoRaWAN: A Cost Analysis for the Industry 4.0

Exploiting the advantages brought by long-range radio communications and extremely low power consumptions, LoRaWAN is capable to support low rate industry 4.0 services. Despite being energy efficient, LoRa motes can still undergo frequent battery replenishments caused by the monitoring requirements of industrial applications. Duty-cycle constrained operations can partially face this issue at the expense of increased communication delays, which, in turn, inflate higher costs due to damaged products on the production line. This letter proposes a model to analyze this cost tradeoff against different sensing intervals. It further highlights the impact of energy harvesting sources on this cost relationship mapping a way toward improved production efficiency.

Communication Schemes for Centralized and Decentralized Event-Triggered Control Systems

Energy constraint long-range wireless sensor/actuator-based solutions are theoretically the perfect choice to support the next generation of city-scale cyber-physical systems. Traditional systems adopt periodic control which increases network congestion and actuations while burdens the energy consumption. Recent control theory studies overcome these problems by introducing aperiodic strategies, such as event-triggered control (ETC). In spite of the potential savings, these strategies assume actuator continuous listening, while ignoring the sensing energy costs. In this paper, we fill this gap, by enabling sensing and actuator listening duty cycling and proposing two innovative medium access control protocols for three decentralized ETC approaches. A laboratory experimental test bed, which emulates a smart water network, was modeled and extended to evaluate the impact of system parameters and the performance of each approach. Experimental results reveal the predominance of the decentralized ETC against the classic periodic control either in terms of communication or actuation by promising significant system lifetime extension.

Multi-Parameter Wireless Monitoring and Telecommand of a Rocket Payload: Design and Implementation

A rocket system generally consists of two parts, the rocket motor and the payload. The payload system is built of several sensors such as accelerometer, gyroscope, magnetometer, and also a surveillance camera. These sensors are used to monitor the rocket in a three-dimensional axis which determine its attitude. Additionally, the payload must be able to perform image capturing in a certain distance using telecommand. This article is intended to describe the design and also the implementation of a rocket payload which has attitude monitoring and telecommand ability from the ground control station using a long-range wireless module Digi XBee Pro 900 HP.

IoT-based wireless seismic quality control

At the present, sensors are everywhere across different sectors of the oil and gas industry. Seismic acquisition in upstream, pipeline monitoring in midstream, and asset tracking in downstream are examples of applications in which we need more and more sensors to satisfy a pressing need for accuracy. Sensor data in many cases should be quickly aggregated and coordinated, sometimes from harsh environments where crew intervention and maintenance must be minimized for safety and cost reasons. This mandates data collection/transmission strategies that are power efficient and demand minimal maintenance to operate autonomously. To address this issue, a unified wireless sensing framework is required that consists of the following three components: low-power, long-range wireless sensors with inherent compatibility with the “Internet of Things” (IoT); advanced scalable wireless networking protocols; and data storage/analytics on the cloud for analysis and decision making. These three components combined create a flexible, plug-and-play, scalable network that provides worldwide accessibility to the data and is cost efficient because you pay as you grow for storage and computation. Aiming at materializing such a ubiquitous wireless sensing paradigm, we have studied the feasibility of using a new family of IoT-based wireless technologies: so-called low-power wide-area networks (LPWANs). We have conducted a proof-of-concept field test in which we have employed LoRa, a predominant member of the LPWAN family, for real-time seismic quality control/monitoring. Our field test results corroborate that cheap (less than US$10) subscription-free LoRa wireless modules can be embedded into our seismic recording systems allowing us to transmit more than 6 MB of data per node per day, while the data can be transmitted over distances of a few kilometers with less than a milliwatt of average power consumption. The transmitted data can be monitored in real time on the cloud for further analysis and decision making.

A comparative study of LPWAN technologies for large-scale IoT deployment

Abstract By 2020, more than 50 billion devices will be connected through radio communications. In conjunction with the rapid growth of the Internet of Things (IoT) market, low power wide area networks (LPWAN) have become a popular low-rate long-range radio communication technology. Sigfox, LoRa, and NB-IoT are the three leading LPWAN technologies that compete for large-scale IoT deployment. This paper provides a comprehensive and comparative study of these technologies, which serve as efficient solutions to connect smart, autonomous, and heterogeneous devices. We show that Sigfox and LoRa are advantageous in terms of battery lifetime, capacity, and cost. Meanwhile, NB-IoT offers benefits in terms of latency and quality of service. In addition, we analyze the IoT success factors of these LPWAN technologies, and we consider application scenarios and explain which technology is the best fit for each of these scenarios.

Long-Range Wireless Interrogation of Passive Humidity Sensors Using Van-Atta Cross-Polarization Effect and Different Beam Scanning Techniques

This paper presents a method for the remote interrogation of batteryless humidity sensors based on statistical estimations and 3-D beam scanning techniques. As a proof-of-concept demonstration, a Van-Atta reflectarray sensor is interrogated with a 24-GHz frequency-modulated continuous-wave transceiver at various reading ranges. The extension of the proposed approach to passive or moving sensors is reported, and the measurement results are discussed. The relative humidity (RH) is derived from the statistical analysis of multidimensional radar echoes, while method is proposed to detect the sensor among clutter without knowing its exact position. Moreover, it is demonstrated that the cross-polarization effect of the Van-Atta reflectarray combined with the 3-D beam scanning technique allows the indoor measurement of the RH up to 58 m.

Wireless Power Transfer to Millimeter-Sized Nodes Using Airborne Ultrasound.

We propose the use of airborne ultrasound for wireless power transfer to mm-sized nodes, with intended application in the next generation of the Internet of Things (IoT). We show through simulation that ultrasonic power transfer can deliver 50 [Formula: see text] to a mm-sized node 0.88 m away from a ~ 50-kHz, 25-cm2 transmitter array, with the peak pressure remaining below recommended limits in air, and with load power increasing with transmitter area. We report wireless power recovery measurements with a precharged capacitive micromachined ultrasonic transducer, demonstrating a load power of 5 [Formula: see text] at a simulated distance of 1.05 m. We present aperture efficiency, dynamic range, and bias-free operation as key metrics for the comparison of transducers meant for wireless power recovery. We also argue that long-range wireless charging at the watt level is extremely challenging with existing technology and regulations. Finally, we compare our acoustic powering system with cutting edge electromagnetically powered nodes and show that ultrasound has many advantages over RF as a vehicle for power delivery. Our work sets the foundation for further research into ultrasonic wireless power transfer for the IoT.

On the Application of IoT: Meteorological Information Display System Based on LoRa Wireless Communication

ABSTRACTWireless sensor networks (WSNs) have tremendous applications in a variety of industrial and the public Internet of Things (IoT) where information can be delivered through embedded and networked devices. In this paper, we propose a new architecture underlining IoT realm and we implement a long-range (LoRa) wireless radio-based information display system. In particular, using the commercially available LoRa™, we develop WSN infrastructures by using microcontroller to manage the required data from and to a 3G gateway as well as the LoRa™ nodes. Meteorological information is crucial in various aspects of life, so is in the field of agriculture. Lack of access to good information technology infrastructure in the rural region of developing countries has deprived farmers of timely weather information and which can cause significant losses in production and economy. Thus, this paper describes our work on the real-time implementation of a LoRa-based network. The work is mainly intended for rural farmers of developing countries considering the realization of IoT, information and communication technology. The proposed system is able to wirelessly deliver well-timed and valuable information for farmers across the country to boost productivity and minimize needless wastes before, during and after the harvesting period. Furthermore, in this study we proved the functionality of the entire WSN infrastructure by testing data transmission–reception in a non-line of sight environment among the gateway and LoRa™ transceiver nodes considering both indoor-to-outdoor and outdoor-to-outdoor scenarios.

MIMO Wireless Power Transfer for Mobile Devices

Since the time of Nikola Tesla, the dream of ubiquitous wireless power transfer (WPT) has tantalized generations of inventors and engineers. A practical, ubiquitous WPT infrastructure could offer tremendous benefits for mobile devices, such as extending battery lifetime, on-the-fly recharging, or, in some cases, eliminating batteries and pesky charging cords altogether. But these benefits can be achieved only if the spatial and temporal distribution of wireless power can be controlled. The authors consider approaches to achieving control over the distribution of long-range (electromagnetic far-field) wireless power, using multi-input, multi-output (MIMO) concepts adapted from the communication domain. They survey recent results in MIMO WPT theory and experiment, and conclude with their own experimental evidence that MIMO WPT can leverage the physics of multipath propagation to selectively enhance or block wireless power delivery, with a typical control range of 20 dB (100 times) in practical indoor environments. This article is part of a special issue on energy harvesting.

QoS for Long-Range Wireless Sensors Under Duty-Cycle Regulations with Shared Activity Time Usage

Long-range radio can connect sensors/IoT devices without complex and costly deployment of relay nodes. However, this flexibility comes with stricter legal regulations such as maximum radio activity time per 1-hour period. Under such constraints it is difficult to provide service guarantees, which is quite paradoxical when devices are deployed for surveillance systems. The approach we propose allows devices to go “exceptionally” beyond the activity time limitation by borrowing time from other devices. The mechanism is not intended to be used on a regular basis, where a device is commissioned to always report data at a rate that makes it consuming more than the allowed duty-cycle limitation, but to offer a “last chance” solution for providing better surveillance service guarantees while globally satisfying duty-cycle regulations. The proposition has been implemented on our long-range image sensor platform, and preliminary experiments show that it can maintain the system’s consistency and keep the number of control messages small while being capable of handling sleep-wakeup behavior and dynamic insertion of new devices. Although initially targeted for image sensors, the proposition can also be deployed to increase the quality of service of traditional sensors by guaranteeing that important messages can be sent despite the duty-cycle regulation limit.

Smart Water Networks and Cyber Security

Smart water networks are instrumented, interconnected water systems that integrate data, computation, control, and communication technologies. They aim to improve system performance and resilience as well as consumer satisfaction and engagement. Partially inspired by advances in electric grid technology, smart water networks have ushered in a new era in design, operation, and management of urban water infrastructure. Contemporary advances and increased interest in smart water network technology are evident through development of a broad array of industry solutions and adoption by numerous water/wastewater utilities. Proliferation of, and increased maturity in, advanced metering infrastructure (AMI), data analytics, and automation technologies has resulted in commercial, field-proven products such as Accenture’s Water Analytics, Arqiva’s long-range radio communication suite, and i2O’s PRV Remote Control solutions. Such technologies have been adopted by utilities worldwide—by Thames Water in the United Kingdom (Accenture 2014), which launched a 15-year program to deploy smart meters across 3.3 million properties; and Philippines Manila Water, which deployed data-driven pressure optimization to enhance services provided to over 6.2 million people. The exponential development and deployment has several compelling drivers, which include escalating droughts, aging infrastructure, increasing water demand and costs, and environmental impacts. Smart water management as an intelligent approach promises enhanced situational awareness and real-time monitoring, predictive control, crisis response/recovery, and self-healing operations. This technological promise has manifested itself through success stories like South African eThekwini Water’s reported 67% mains burst reduction and Romanian APA Nowa Water’s 20% energy consumption reduction through smart pressure management (i2O Water 2015). Merging of cyberspace with physical water assets that are accountable for such tremendous promises, nevertheless, has also exported the malignancies of cyberspace to the traditionally ingenuous infrastructure environments.

Transmit energy-efficiency for long-range wireless communications from battery-powered unmanned systems

The transmit energy efficiency of long-range wireless communications from battery-powered unmanned systems over packet erasure channels is analyzed for space- and polarization-based multiple-input multiple-output (MIMO) architectures with and without linear precoding. Theoretical and emulation results generated from a hybrid hardware/software test bed indicate that when packet erasures are considered, 4 × 4 MIMO architectures with precoding can offer significant energy efficiency gains relative to nonprecoded MIMO systems. In the lower signal-to-noise ratio regime, we find that operating points exist for the different MIMO architectures that provide near maximum spectral efficiency while operating at a local minimum in energy consumption. At these operating points, transceiver operating times are determined for a range of battery capacities.

Killing New Vistas with the Over-Regulation of Recreational 'Drone' Use

In the last few years, there has been a dramatic increase in the use of remote-controlled copters – often given the convenient but misleading epithets of unmanned aerial vehicles or “drones” – by recreational users to capture aerial photographs and videos on an unprecedented scale. Asia is no exception. The convergence of cutting-edge technological developments in gyroscopic gimbals, long-range wireless transmissions, GPS-enabled stabilisation, GPS-enabled flightpath-preprogramming, first-person-views, and compact digital imaging has led to the proliferation of affordable camera-carrying “drones” that even hobbyists can pilot with reasonable safety. Thus far, despite purported controversies there have not been any reports of serious mishaps involving the use of these rotor-propelled copters – mainly because these copters are incapable of heavy payloads and, in any event, have a series of fail-safe tools. Yet, there has been a consistent stream of public concern relating to issues of safety, privacy, and even the protection of monopolised commercial interests. Lost in the paranoid cacophony is a question that warrants proper legislative reflection: how can such tools be regulated in a way that is proportionate and sensible? There are some jurisdictions that have already tabled legislation to regulate recreational droning, while many others are planning to introduce the same, while some are relying on clearly anachronistic legislation as a stop-gap measure. Can the law keep pace with new technology, or is the challenge too formidable? How is Asia – the principal manufacturer, exporter, and user of many of these copters – responding to the situation? This paper, presented at the 2015 ASLI Conference, will examine some of the laws in the region and beyond to demonstrate how the right balance between the freedom of expression and freedom to create art, and the purported competing demands of safety, privacy, and commercial interests can be struck – or not. Questions relating to the appropriate height, distance, weight, airbase-proximity, and line of sight limits; the necessity of a licensing and/or training scheme; and the supposed problems of privacy intrusion and obstruction of commercial interests will be addressed. Ultimately, however, what is needed first and foremost is a complete mind-set shift in the legislators before one goes down the path of no return.

Enhancement of RF Tag Backscatter Efficiency With Low-Power Reflection Amplifiers

Increasing backscatter tag communication ranges is crucial for the development of low-power long-range wireless sensor networks. A major limitation for increasing the signal-to-noise ratio (SNR) for RF identification tags lies in the fact that tag antennas are terminated with passive loads for modulation, which yields reflection-coefficient values less than unity. Recent work in the field has exploited reflection amplifiers that achieve reflection-coefficient values larger than unity to increase the communication range. However, most of these systems rely on increasing the reflection coefficient at one modulation state only, which is suboptimal. In this paper, an analysis is given for the optimal way to utilize a reflection amplifier and how this compares to suboptimal practices. To demonstrate the concept, a tag is designed that achieves reflection-coefficient values higher than unity for both states in the 900-930-MHz band. The two values are antipodal, thus maximizing the tag SNR for a given amplifier. The system comprises of an ultra-low-power reflection amplifier with up to 10.2-dB gain and sub-milliwatt power consumption, and a phase-shift modulator that selectively alternates the phase of the backscatter signal between 0 ° and 180 ° . The reflection amplifier-phase modulator system is experimentally characterized in terms of gain, power consumption, and backscatter efficiency.