Bruno J. Silva

Experimental Link Quality Characterization of Wireless Sensor Networks for Underground Monitoring

Wireless underground sensor networks (WUSNs) are a category of wireless sensor networks (WSNs) with buried nodes, which communicate wirelessly through soil with sensor nodes located aboveground. As the communication medium (i.e., soil) between traditional over-the-air WSNs and WUSNs differs, communication characteristics have to be fully characterized for WUSNs, specifically to enable development of efficient communication protocols. Characterization of link quality is a fundamental building block for various communication protocols. The aim of this paper is to experimentally investigate the link quality characteristics of the three communication channels available in WUSNs for underground pipeline monitoring to gain further insight into protocol development for WUSNs. To this end, received signal strength (RSS), link quality indicator (LQI), and packet reception ratio (PRR) are characterized for the three communication channels in WUSNs. The RSS and PRR results show that the underground-to-underground channel is highly symmetric and temporally stable, but its range is severely limited, and that the aboveground-to-underground/underground-to-underground channels are asymmetric and exhibit similar temporal properties to over-the-air communication channels. Interestingly, the results show that RSS is a better indicator of PRR than LQI for all three channels under consideration.

Machine-to-Machine: Possible applications in industrial networks

Industry operators and plant designers are constantly seeking economic methods to improve plant output, maximize process efficiency and reduce system downtime. This is typically facilitated through industrial automation and control in an industrial network. The industrial network typically consists of a closed network of specialized controllers and sensors with the singular purpose of automation and process control. Machine-to-Machine (M2M) networking can potentially be integrated into the industrial network to expand on the benefits of industrial networking through the access and distribution of additional information. By networking the individual process controllers as well as other relevant sensors and machines a wealth of information can be generated to better model, control and manage the plant. A host of technologies are available to facilitate M2M based on the specific applications and system requirements, allowing both custom and standardized solutions. This report provides a brief overview of M2M in the context of general industry as well as its potential applications in industrial automation and process control.

IR-UWB-Based Non-Line-of-Sight Identification in Harsh Environments: Principles and Challenges

Impulse radio ultrawideband ranging has recently received significant attention due to the high accuracy it can achieve. Although most research efforts have focused on ranging in indoor and outdoor environments, other environments such as harsh industrial environments introduce unique challenges. This paper discusses the impact of propagation characteristics of harsh industrial environments on ranging accuracy, and also discusses principles and challenges of non-line-of-sight identification in industrial scenarios. To illustrate these challenges, a measurement campaign using 802.15.4a radios was conducted in a Heavy Machines Laboratory. The results show that the non-line-of-sight condition can be accurately identified if adequate models for such an environment are used.

Experimental study of UWB-based high precision localization for industrial applications

Recent developments in wireless sensor networks have inspired applications which require high accuracy localization. Impulse radio ultra wide-band technology has a fine time resolution, allowing accurate determination of the time of arrival at the receiver, making it a serious contender for accurate ranging, in comparison to narrow-band technologies. In this paper, we present a UWB based 3D real-time indoor positioning system with 802.15.4a compliant wireless nodes. Results from measurement campaigns reveal that for line-of-sight (LOS) scenarios 11 cm accuracy and 2 cm precision without any postprocessing (i.e. filtering) are possible, hence demonstrating the capability of accurate UWB-based localization using trilateration, resulting in a fast and non-complex algorithm that provides high precision positioning. The proposed system presents an initial step in developing a high precision system for localization in industrial applications.

A Survey on 5G Networks for the Internet of Things: Communication Technologies and Challenges

The Internet of Things (IoT) is a promising technology which tends to revolutionize and connect the global world via heterogeneous smart devices through seamless connectivity. The current demand for machine-type communications (MTC) has resulted in a variety of communication technologies with diverse service requirements to achieve the modern IoT vision. More recent cellular standards like long-term evolution (LTE) have been introduced for mobile devices but are not well suited for low-power and low data rate devices such as the IoT devices. To address this, there is a number of emerging IoT standards. Fifth generation (5G) mobile network, in particular, aims to address the limitations of previous cellular standards and be a potential key enabler for future IoT. In this paper, the state-of-the-art of the IoT application requirements along with their associated communication technologies are surveyed. In addition, the third generation partnership project cellular-based low-power wide area solutions to support and enable the new service requirements for Massive to Critical IoT use cases are discussed in detail, including extended coverage global system for mobile communications for the Internet of Things, enhanced machine-type communications, and narrowband-Internet of Things. Furthermore, 5G new radio enhancements for new service requirements and enabling technologies for the IoT are introduced. This paper presents a comprehensive review related to emerging and enabling technologies with main focus on 5G mobile networks that is envisaged to support the exponential traffic growth for enabling the IoT. The challenges and open research directions pertinent to the deployment of massive to critical IoT applications are also presented in coming up with an efficient context-aware congestion control mechanism.

Practical challenges of IR-UWB based ranging in harsh industrial environments

Impulse radio ultra-wideband (IR-UWB) ranging and localization have recently received significant attention due to the high accuracy and precision. This high accuracy can be exploited for many location aware applications in a wide variety of environments. Although most research efforts have focused on location-aware applications for indoor or outdoor environments, there are other environments, such as industrial, which introduce unique challenges. In an effort to understand how industrial environments affect IR-UWB based ranging and localization performance, this paper introduces the principles behind ranging in industrial environments and highlights practical challenges which have an impact on the ranging accuracy of IR-UWB. Results from field tests which illustrate the impact of harsh conditions on the ranging accuracy are presented.

On link quality aware routing for industrial wireless sensor networks

Wireless communication is susceptible to attenuation, multi-path and interference. Traditional routing metrics such as hop-count do not perform optimally because they do not consider link quality. For industrial settings, which are characterized by harsh conditions, link quality aware routing can significantly outperform hop-count based routing metrics. This paper presents an overview of the current state of research in this domain and comments on the use of link quality aware routing in industrial wireless sensor networks.

Design of a water management system

Water is a vital component in our daily lives, and a precious resource to human race. This paper describes the work carried out on the design of a water management system that can log pressure and pH readings wirelessly and determine if there is a water leak within the pipe system or if the pH levels of the water are safe enough for human consumption. A pipe monitoring system was designed, implemented and fitted with pressure sensors as well as pH sensors. The data received from the sensors was processed by a microcontroller and sent to a computer via a wireless communication module. A graphical user interface was also implemented to display the data received and to trigger an alert if any irregularities (pipe leak/burst or dangerous pH levels) are detected in real time, and leak locations can be determined.

Positioning infrastructure for industrial automation systems based on UWB wireless communication

In various industrial automation applications, positioning enables location awareness which can be exploited in applications such as robotic precision control, amongst others. This paper discusses positioning for industrial automation applications. Examples of applications from an infrastructure perspective are presented, and the integration of high precision positioning technology into existing network infrastructure for such applications is discussed, as well as challenges involved. An impulse-radio ultra-wideband 802.15.4a based system for high accuracy/precision positioning is presented, which shows promising results, therefore motivating the use of UWB as a high accuracy and precision technology for positioning applications in future industrial automation systems.

A Web-Based Office Climate Control System Using Wireless Sensors

Conventional heating, ventilating, and air conditioning (HVAC) systems usually achieve the desired control level by means of simple ON-OFF control, which can often result in high energy wastage. A potential solution to this issue is intelligent self-regulating HVAC controllers, which base their actions/decisions on sensor data. In this paper, an office climate monitoring and control system is designed and implemented. The system consists of various wireless sensor nodes and a control node. The sensor nodes provide the sensor data necessary to determine occupancy and the control node executes the algorithm, which decides whether to activate cooling or heating based on the sensor data. This system can serve as a controller and can be integrated into HVAC systems in smart buildings. It is shown that the developed control algorithm executed on the control node results in an improvement of up to 39% in energy efficiency over conventional ON-OFF controllers for HVAC systems.