Wireless Channel Path-Loss Modelling for Agricultural and Vegetation Environments: A Survey

This work undertakes an extensive survey of the channel modelling methods and path-loss characterization carried out in agricultural fields and vegetation environments in an attempt to study the state-of-the-art in this field, which, though vastly explored, still presents extremely diverse opportunities and challenges. The interface for communication between nodes in a typical agricultural field is the wireless channel or air interface, making it imperative to address the impairments that are exclusive to such a communication scenario by studying the characteristics of the medium. The performance of the channel is a direct indicator of the quality of communication. It is required to have a lucid understanding of the channel to ensure quality in transmission of the required information, while simultaneously ensuring maximum capacity by employing limited resources. The impairments that are the very nature of a typical wireless channel are treated in an explicit manner covering the theoretical and mathematical models, analytical aspects and empirical models. Although there are several propagation models characterized for generic indoor and outdoor environments, these cannot be applied to agricultural, vegetation, forest and foliage scenarios due to the various additional factors that are specific to these environments. Owing to the wide variety, size, properties and span of the foliage, it also becomes extremely challenging to develop a generic predictive model for all kinds of crops or vegetation. The survey is categorized into fields containing specific crops, greenhouse environment and forest/foliage scenarios and the key findings are presented

Nodos sensores inalámbricos con antenas directivas de banda simple o doble para aplicaciones en agricultura

Abstract Introduction: This paper presents the design of two wireless sensor nodes, with communications systems that integrate in one case a broadband antenna for operation in the 900MHz and 2.4GHz bands, along with a circuit that allows to select the appropriate radio for operation in some of these bands with the same antenna and the other makes use of a high gain antenna for operation in the 2.4GHz band. The proposed design offers a solution to the problem of propagation of radio frequency (RF) signals in forests and plantations for applications in smart agriculture that make use of wireless sensor networks (WSN). Objective: Design of two wireless sensor nodes, with communications systems that integrate directive antennas in one case for dual band operation (900MHz-2.4GHz) and in the other with high gain antennas (2.4GHz) for applications in smart agriculture. Method: The design of the wireless nodes makes use of the PSoC (programmable chip system) model CY8CKIT-059 5LP, which integrates temperature, humidity, inclination, distance, light intensity and movement sensors that use ZigBee as a wireless communication protocol. The antennas are designed with appropriate electromagnetic simulators and the resulting prototypes from this process are characterized in impedance by means of a vector network analyzer (VNA) and radiation patterns in an anechoic chamber. The full operation of the nodes is validated in the laboratory and in open spaces. Results: The double-band node with logarithmic antenna allows packet transfer at distances of 4.1km (915MHz) and 938m (2.44GHz), along with a switching circuit that allows one of the bands to be selected depending on the propagation characteristics of the medium where the node will be installed. On the other hand, the node with SPA antenna allows transfer of packets up to 2.5km (2.44GHz). The antenna characterization results are as follows: The logarithmic antenna has a maximum gain of 2.74dBi (915MHz) and 3.06dBi (2.44GHz) respectively, with an impedance bandwidth of 3.196:1, for an S11 <-10dB. The SPA antenna resonates at a center frequency of 2.44 GHz with a gain of 7.2 dBi; an impedance bandwidth of 16.8%, for an S11 <-10dB. Conclusions: This proposal improves the performance in wireless sensor networks since the approaches allow modularity, versatility and application in different areas including agriculture, enabling longer reaches and a more extensive coverage compared to the nodes that make use of conventional XBee antennas.Introducción: Este artículo presenta el diseño de dos nodos de sensores inalámbricos, con sistemas de comunicaciones que integran en un caso una antena de banda ancha para operación en las bandas de 900MHz y 2.4GHz, junto con un circuito que permite seleccionar el radio apropiado para operación en alguna de estas bandas con la misma antena y el otro hace uso de una antena de alta ganancia para operación en la banda de 2.4GHz. El diseño propuesto ofrece una solución al problema de propagación de señales de radio frecuencia (RF) en bosques y plantaciones para aplicaciones en agricultura inteligente que hacen uso de redes de sensores inalámbricos (WSN). Objetivo: Diseñar dos nodos de sensores inalámbricos, con sistemas de comunicaciones que integran antenas directivas en un caso para operación en doble banda (900MHz-2.4GHz) y en el otro con antenas de alta ganancia (2.4GHz) para aplicaciones en agricultura inteligente. Metodología: El diseño de los nodos inalámbricos hace uso del PSoC (sistema programable en chip) modelo CY8CKIT-059 5LP, al cual se integran sensores de temperatura, humedad, inclinación, distancia, intensidad de luz y movimiento que utilizan ZigBee como protocolo de comunicación inalámbrica. Las antenas son diseñadas con simuladores electromagnéticos apropiados y los prototipos resultantes de este proceso son caracterizados en impedancia mediante un analizador de redes (VNA) y en diagrama en una cámara anecoica. La operación integral de los nodos se valida en el laboratorio y en espacios abiertos. Resultados: El nodo de doble banda con antena logarítmica permite transferencia de paquetes a distancias de 4.1km (915MHz) y de 938m (2.44GHz), junto con un circuito de conmutación que permite seleccionar una de las bandas dependiendo de las características de propagación del medio donde se instalará el nodo. Por otra parte, el nodo con antena SPA permite transferencia de paquetes hasta 2.5Km (2.44GHz). Los resultados de la caracterización de las antenas son: La antena logarítmica presenta una ganancia máxima de 2.74dBi (915MHz) y 3.06dBi (2.44GHz) respectivamente, con un ancho de banda de impedancia de 3.196:1, para un <-10dB. La antena SPA resuena a una frecuencia central de 2.44 GHz con una ganancia de 7.2 dBi; un ancho de banda de impedancia del 16.8%, para un <-10dB. Conclusiones: La propuesta consigue mejorar el desempeño en redes inalámbricas de sensores por su modularidad, versatilidad y su aplicación en diferentes áreas incluida la agricultura, lo que permite obtener mejores alcances y cobertura más amplia cuando se compara con los nodos que hacen uso de antenas XBee convencionales

CHANNEL MODELING FOR FIFTH GENERATION CELLULAR NETWORKS AND WIRELESS SENSOR NETWORKS

In view of exponential growth in data traffic demand, the wireless communications industry has aimed to increase the capacity of existing networks by 1000 times over the next 20 years. A combination of extreme cell densification, more bandwidth, and higher spectral efficiency is needed to support the data traffic requirements for fifth generation (5G) cellular communications. In this research, the potential improvements achieved by using three major 5G enabling technologies (i.e., small cells, millimeter-wave spectrum, and massive MIMO) in rural and urban environments are investigated. This work develops SPM and KA-based ray models to investigate the impact of geometrical parameters on terrain-based multiuser MIMO channel characteristic. Moreover, a new directional 3D channel model is developed for urban millimeter-wave (mmW) small cells. Path-loss, spatial correlation, coverage distance, and coherence length are studied in urban areas. Exploiting physical optics (PO) and geometric optics (GO) solutions, closed form expressions are derived for spatial correlation. Achievable spatial diversity is evaluated using horizontal and vertical linear arrays as well as planar 2D arrays. In another study, a versatile near-ground field prediction model is proposed to facilitate accurate wireless sensor network (WSN) simulations. Monte Carlo simulations are used to investigate the effects of antenna height, frequency of operation, polarization, and terrain dielectric and roughness properties on WSNs performance

Design and Field Test of a WSN Platform Prototype for Long-Term Environmental Monitoring

Long-term wildfire monitoring using distributed in situ temperature sensors is an accurate, yet demanding environmental monitoring application, which requires long-life, low-maintenance, low-cost sensors and a simple, fast, error-proof deployment procedure. We present in this paper the most important design considerations and optimizations of all elements of a low-cost WSN platform prototype for long-term, low-maintenance pervasive wildfire monitoring, its preparation for a nearly three-month field test, the analysis of the causes of failure during the test and the lessons learned for platform improvement. The main components of the total cost of the platform (nodes, deployment and maintenance) are carefully analyzed and optimized for this application. The gateways are designed to operate with resources that are generally used for sensor nodes, while the requirements and cost of the sensor nodes are significantly lower. We define and test in simulation and in the field experiment a simple, but effective communication protocol for this application. It helps to lower the cost of the nodes and field deployment procedure, while extending the theoretical lifetime of the sensor nodes to over 16 years on a single 1 Ah lithium battery

Rede de sensores sem fios para monitorização de plantações de Salicornia

mestrado em Engenharia Eletrónica e TelecomunicaçõesA Salicornia ramosissima é uma planta que cresce em ambientes salinos sendo famosa pelas suas características benéficas nas mais diversas áreas, tais como alimentação, medicina e biocombustíveis. Na Universidade de Aveiro, um grupo de investigadores na área da biologia contribuíram para uma melhor compreensão do crescimento e desenvolvimento da Salicornia na Ria de Aveiro no que diz respeito à salinidade, fases de crescimento e sobrevivência. No contexto da Internet das Coisas, as redes de sensores são um tema de estudo dado o vasto número de aplicações, pelo que, diversas tecnologias têm aparecido no mercado de modo a garantir qualidade de serviço aos seus clientes. Foi assim proposto o desenvolvimento de uma solução que monitorize os parâmetros desta planta no seu habitat natural. Uma vez que este ambiente é selvagem e propício a roubos, os requisitos principais são: consumos energéticos e custos de desenvolvimento e implementação baixos. Ao longo desta dissertação são apresentadas as tecnologias de redes de sensores actuais no mercado, bem como um estudo sobre os sensores necessários para a monitorização de uma plantação de Salicornia e o protocolo que favorece as necessidades da rede em questão.The Salicornia ramosissima is a plant that grows in a salt-marsh environment and it has become famous because of their bene cial characteristics in several areas such as: human nutrition, biofuels and medicine. At University of Aveiro, a group of biology researches contributed to a better understanding of a Salicornia population biology in Ria de Aveiro, especially aspects related to salinity, plant growth, and survival. In the context of the Internet of Things, the wireless sensor networks is an emergent area of studies. Nowadays, there are several tecnologies in the market to answer the requirements and o er quality of service to the WSN's users. It was proprosed a solution to monitor the Salicornia parameters in their natural habitat. Once the habitat is considerer wild, it is conducive to theft. Because of that, the main requirements for this network are to create a low cost and low power consumption network. Along this dissertation, are presented and discussed some emergent wireless tecnologies in the market, as well a discussion about the sensors needed to monitor the Salicornia plantation and the communication protocol which answers the needs of the network

The applications of autonomous systems to forestry management

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; in conjunction with the Leaders for Global Operations Program at MIT, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 132-137).Public and private timberland owners continually search for new, cost effective methods to monitor and nurture their timber stand investments. Common management tasks include monitoring tree growth and tree health, estimating timber value and preventing wildfire. Many of these tasks are both manual and costly due to the vast areas and remote locations involved. Forestry experts predict that multi-vehicle autonomous systems may enable new, cost effective methods for performing various forest management tasks[1]. However, it remains unclear how these technologies may be applied, or where to focus development efforts. This research attempts to address this gap in literature, linking state-of-the-art research in forestry management science, robotics and autonomous systems, and product design and development. This thesis begins by reviewing existing forestry management practices and discussing a number of challenges identified through industry interviews and research. Modem product design methods are reviewed, and used to generate ideas for a number of new concept systems. Three design concepts are presented as detailed case studies. The data sets, methods and proposed systems discussed in this thesis may be used to guide future research in forestry management science, and drive further innovation in the emerging field of commercial and civilian autonomous systems. Key words: Forestry Management, Forestry Science, Robotics and Autonomous Systems, Unmanned Aerial Vehicles (UAV), Unmanned Aerial Systems (UAS), Product Design and Development, Light Detection and Ranging (LiDAR)by Joshua Przybylko.S.M.M.B.A

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering