scholarly journals Cityscape LoRa Signal Propagation Predicted and Tested Using Real-World Building-Data Based O-FDTD Simulations and Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2717
Author(s):  
Ricardo M. R. Adão ◽  
Eduardo Balvís ◽  
Alicia V. Carpentier ◽  
Humberto Michinel ◽  
Jana B. Nieder
Keyword(s):  
Communication Networks ◽  
Real World ◽  
Smart Cities ◽  
Low Cost ◽  
Fdtd Method ◽  
Signal Propagation ◽  
Wireless Communication Networks ◽  
Coverage Area ◽  
Concrete Walls ◽  
Signal Coverage

The age of the Internet of Things (IoT) and smart cities calls for low-power wireless communication networks, for which the Long-Range (LoRa) is a rising star. Efficient network engineering requires the accurate prediction of the Received Signal Strength Indicator (RSSI) spatial distribution. However, the most commonly used models either lack the physical accurateness, resolution, or versatility for cityscape real-world building distribution-based RSSI predictions. For this purpose, we apply the 2D electric field wave-propagation Oscillator Finite-Difference Time-Domain (O-FDTD) method, using the complex dielectric permittivity to model reflection and absorption effects by concrete walls and the receiver sensitivity as the threshold to obtain a simulated coverage area in a 600 × 600 m2 square. Further, we report a simple and low-cost method to experimentally determine the signal coverage area based on mapping communication response-time delays. The simulations show a strong building influence on the RSSI, compared against the Free-Space Path (FSPL) model. We obtain a spatial overlap of 84% between the O-FDTD simulated and experimental signal coverage maps. Our proof-of-concept approach is thoroughly discussed compared to previous works, outlining error sources and possible future improvements. O-FDTD is demonstrated to be most promising for both indoors and outdoors applications and presents a powerful tool for IoT and smart city planners.

scholarly journals JMAC Protocol: A Cross-Layer Multi-Hop Protocol for LoRa

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6893
Author(s):  
Juan José López López Escobar ◽  
Felipe Gil-Castiñeira ◽  
Rebeca P. Díaz Díaz Redondo
Keyword(s):  
Communication Networks ◽  
Smart Cities ◽  
Area Network ◽  
Wireless Communication Networks ◽  
Wide Area Network ◽  
Coverage Area ◽  
Radio Technology ◽  
Long Lifetime ◽  
Good Coverage ◽  
Non Line Of Sight

The emergence of Low-Power Wide-Area Network (LPWAN) technologies allowed the development of revolutionary Internet Of Things (IoT) applications covering large areas with thousands of devices. However, connectivity may be a challenge for non-line-of-sight indoor operation or for areas without good coverage. Technologies such as LoRa and Sigfox allow connectivity for up to 50,000 devices per cell, several devices that may be exceeded in many scenarios. To deal with these problems, this paper introduces a new multi-hop protocol, called JMAC, designed for improving long range wireless communication networks that may support monitoring in scenarios such smart cities or Industry 4.0. JMAC uses the LoRa radio technology to keep low consumption and extend coverage area, and exploits the potential mesh behaviour of wireless networks to improve coverage and increase the number of supported devices per cell. JMAC is based on predictive wake-up to reach long lifetime on sensor devices. Our proposal was validated using the OMNeT++ simulator to analyze how it performs under different conditions with promising results.

Security, Privacy, and Trust for Pervasive Computing Applications

2016 ◽  
pp. 327-342
Author(s):  
Sheikh I. Ahamed ◽  
Mohammad Zulkernine ◽  
Munirul M. Haque
Keyword(s):  
Communication Networks ◽  
Pervasive Computing ◽  
Ad Hoc ◽  
Low Cost ◽  
Wireless Communication Networks ◽  
Security Measures ◽  
Embedded Devices ◽  
Trust Models ◽  
Networks Structure ◽  
Privacy Issues

Pervasive computing has progressed significantly during this decade due to the developments and advances in portable, low-cost, and light-weight devices along with the emergence of short range and low-power wireless communication networks. Pervasive computing focuses on combining computing and communications with the surrounding physical environment to make computing and communication transparent to the users in day-to-day activities. In pervasive computing, numerous, casually accessible, often invisible, frequently mobile or embedded devices form an ad-hoc network that occasionally connects to fixed networks structure too. These pervasive computing devices often collect information about the surrounding environment using various sensors. Pervasive computing has the inherent disadvantages of slow, expensive connections, frequent line disconnections, limited host bandwidth, location dependent data, and so forth. These challenges make pervasive computing applications more vulnerable to various security-related threats. However, traditional security measures do not fit well in pervasive computing applications. Since location and context are key attributes of pervasive computing applications, privacy issues need to be handled in a sophisticated manner. The devices in a pervasive computing network leave and join in an ad-hoc manner. This device behavior creates a need for new trust models for pervasive computing applications. In this chapter, we address the challenges and requirements of security, privacy, and trust for pervasive applications. We also discuss the state-of-the-art of pervasive security, privacy, and trust along with some open issues.

scholarly journals LoRaWAN Mesh Networks: A Review and Classification of Multihop Communication

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4273
Author(s):  
Jeferson Rodrigues Cotrim ◽  
João Henrique Kleinschmidt
Keyword(s):  
Large Scale ◽  
Simulation Analysis ◽  
Mesh Networks ◽  
Smart Cities ◽  
Low Cost ◽  
Wide Area ◽  
Area Network ◽  
Full Potential ◽  
Wide Area Network ◽  
Coverage Area

The growth of the Internet of Things (IoT) led to the deployment of many applications that use wireless networks, like smart cities and smart agriculture. Low Power Wide Area Networks (LPWANs) meet many requirements of IoT, such as energy efficiency, low cost, large coverage area, and large-scale deployment. Long Range Wide Area Network (LoRaWAN) networks are one of the most studied and implemented LPWAN technologies, due to the facility to build private networks with an open standard. Typical LoRaWAN networks are single-hop in a star topology, composed of end-devices that transmit data directly to gateways. Recently, several studies proposed multihop LoRaWAN networks, thus forming wireless mesh networks. This article provides a review of the state-of-the-art multihop proposals for LoRaWAN. In addition, we carried out a comparative analysis and classification, considering technical characteristics, intermediate devices function, and network topologies. This paper also discusses open issues and future directions to realize the full potential of multihop networking. We hope to encourage other researchers to work on improving the performance of LoRaWAN mesh networks, with more theoretical and simulation analysis, as well as practical deployments.

scholarly journals Dementia Patient’s Meal Monitoring Systems Using Weight and Temperature Sensors

2021 ◽  
Author(s):  
Ji-Eun Joo ◽  
Haewon Hwang ◽  
Yujin Jeon ◽  
Jaewon Jung ◽  
Yu Hu ◽  
...  
Keyword(s):  
Nursing Homes ◽  
Communication Networks ◽  
Elder Care ◽  
Senile Dementia ◽  
Low Cost ◽  
Temperature Sensors ◽  
Monitoring Systems ◽  
Wireless Communication Networks ◽  
Dementia Patients ◽  
Crucial Information

: This paper presents a couple of meal monitoring systems for senile dementia patients by using electronic weight and temperature sensors. These monitoring systems enable to convey the information of the amount of meal taken by the patients in real-time via wireless communication networks onto the mobile phones of their families or nurses in charge. Thereby, the nurses can easily spot the most desperate patient to take care of while the families can have relief to see the crucial information for survival of their parents at least three times a day. Meanwhile, the senile dementia patients tend to suffer the burn of their tongues because they can hardly recognize the temperature of hot meals served and therefore avoid the burn of tongues. This phenomenon can be discarded by utilizing the meal temperature monitoring system which displays alarm to the patients when the meal temperature is above the reference. These meal monitoring systems can be easily implemented by utilizing low-cost sensor chips and Arduino UNO boards so that elder-care hospitals and nursing homes can afford to exploit them with no additional cost. Hence, we believe that the proposed monitoring systems would be a potential solution to provide a great help and relief not only for the professional nursing nurses working in elder-care hospitals and nursing homes, but also for the families of the dementia patients.

scholarly journals Meal-Monitoring Systems Using Weight and Temperature Sensors for Elder Residents in Long-Term Care Facilities

2022 ◽  
Vol 19 (2) ◽  
pp. 808
Author(s):  
Yu Hu ◽  
Ji-Eun Joo ◽  
Eunju Choi ◽  
Leeho Yoo ◽  
Dukyoo Jung ◽  
...  
Keyword(s):  
Nursing Homes ◽  
Communication Networks ◽  
Elder Care ◽  
Low Cost ◽  
Well Being ◽  
Temperature Sensors ◽  
Monitoring Systems ◽  
Wireless Communication Networks ◽  
Term Care ◽  
Crucial Information

This paper presents a few meal-monitoring systems for elder residents (especially patients) in LTCFs by using electronic weight and temperature sensors. These monitoring systems enable to convey the information of the amount of meal taken by the patients in real-time via wireless communication networks onto the mobile phones of their nurses in charge or families. Thereby, the nurses can easily spot the most patients who need immediate assistance, while the families can have relief in seeing the crucial information for the well-being of their parents at least three times a day. Meanwhile, the patients tend to suffer burns of their tongues because they can hardly recognize the temperature of hot meals served. This situation can be avoided by utilizing the meal temperature-monitoring system, which displays an alarm to the patients when the meal temperature is above the reference. These meal-monitoring systems can be easily implemented by utilizing low-cost sensor chips and Arduino NANO boards so that elder-care hospitals and nursing homes can afford to exploit them with no additional cost. Hence, we believe that the proposed monitoring systems would be a potential solution to provide a great help and relief for the professional nurses working in elder-care hospitals and nursing homes.

scholarly journals Experimental Application of Bluetooth Low Energy Connectionless in Smart Cities

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2735
Author(s):  
Juan Carlos García-Ortiz ◽  
Javier Silvestre-Blanes ◽  
Víctor Sempere-Payá
Keyword(s):  
Communication Networks ◽  
Smart Cities ◽  
Low Cost ◽  
Low Energy ◽  
Bluetooth Low Energy ◽  
Wireless Interference ◽  
Experimental Application ◽  
Heterogeneous Nature ◽  
Wide Availability ◽  
Application Requirements

Communication networks are a key element in the development of Smart Cities. This field is a constantly evolving environment, for which new protocols are constantly appearing. Due to the heterogeneous nature of the technologies, the most appropriate candidate must be selected in order to get the best performance to satisfy the application requirements. One of these protocols is Bluetooth Low Energy (BLE), particularly with the upgrades introduced in version 5.x. Its new features are focused on providing increased range, improving robustness, and expanding beaconing capabilities. Connectionless applications such as information broadcasting in Smart Cities could take advantage of this protocol. Furthermore, the wide availability on common devices (mobile phones, car infotainment, etc.), the deployment of these applications can be carried out easily and at low cost. This paper presents an experimental evaluation of the new robust, long-range radio mode of BLE over a set of Smart Cities scenarios, taking into account different conditions such as wireless interference, distances, dynamicity, etc. The results show a promising performance of the protocol even with these constraints.

scholarly journals Proposal for the Design of Monitoring and Operating Irrigation Networks Based on IoT, Cloud Computing and Free Hardware Technologies

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2318 ◽  
Author(s):  
Luis Manuel Fernández-Ahumada ◽  
Jose Ramírez-Faz ◽  
Marcos Torres-Romero ◽  
Rafael López-Luque
Keyword(s):  
Communication Networks ◽  
Low Cost ◽  
Free Software ◽  
Wireless Communication Networks ◽  
Process Automation ◽  
Internet Connection ◽  
Irrigation Networks ◽  
Node Network ◽  
Software And Hardware ◽  
The Stability

In recent decades, considerable efforts have been devoted to process automation in agriculture. Regarding irrigation systems, this demand has found several difficulties, including the lack of communication networks and the large distances to electricity supply points. With the recent implementation of LPWAN wireless communication networks (SIGFOX, LoraWan, and NBIoT), and the expanding market of electronic controllers based on free software and hardware (i.e., Arduino, Raspberry, ESP, etc.) with low energy requirements, new perspectives have appeared for the automation of agricultural irrigation networks. This paper presents a low-cost solution for automatic cloud-based irrigation. In this paper, it is proposed the design of a node network based on microcontroller ESP32-Lora and Internet connection through SIGFOX network. The results obtained show the stability and robustness of the designed system.

Key Issues and Research Directions in Green Wireless Networking

2015 ◽  
pp. 6186-6194
Author(s):  
Konstantinos B. Baltzis
Keyword(s):  
Communication Networks ◽  
Low Cost ◽  
Wireless Networking ◽  
Future Research ◽  
Wireless Communication Networks ◽  
Research Directions ◽  
Current Trends ◽  
Key Issues ◽  
Future Research Directions ◽  
Ict Infrastructure

A significant part of worldwide energy is consumed by the ICT infrastructure with wireless sector to be among the main contributors to this consumption. As a result, the rising energy costs and increasing carbon footprint of operating wireless communication networks have generated a keen interest in the design and development of “green” networks, that is, networks characterized by energy efficiency, reduced CO2 emissions, and low cost deployment. In this article, we discuss current issues and trends in green wireless networking. We explain the motivation behind it, discuss basic principles, review current trends in the field, and highlight upcoming challenges and future research directions. The aforementioned issues have been treated in detail in the scientific literature. However, the present study overviews current and future trends in green wireless networking with focus on providing an insight into the field that will be useful not only for experts but for non-specialists also.

scholarly journals Optimization of Signal Coverage Area in Mobile Communication Networks

2020 ◽  
pp. 35-45
Author(s):  
O. A. Osahenvemwen
Keyword(s):  
Mathematical Model ◽  
Communication Network ◽  
Communication Networks ◽  
Mobile Communication ◽  
Load Capacity ◽  
Base Station ◽  
Coverage Area ◽  
Mobile Communication Network ◽  
Signal Coverage ◽  
Mobile Communication Networks

This study presents the optimization of signal coverage area in third generation WCDMA technology of mobile communication networks, aim at improving signal coverage area or overcoming the presence dead zone in mobile communication network. Various parameters that affect Signal coverage area in mobile communication network were determined. Optimization mathematical model based on Lagrange mathematical method was developed in line with the necessary parameters and characteristics. The developed mathematical model was simulated using MATLAB and Wolfram Mathematical Software using data obtain from mobile communication Network ‘A’ at Asaba, Delta State. The obtained data were number of duplex channels, frequency, load capacity of the base station, interference, distance power received, power transmitted etc. The result obtain are the critical points with fade-off of the radio signal. The coverage area indicates a non-linear function, therefore to minimize threshold parameter such as interference; pathloss and power received values will increase as the coverage area of the base station increases.

scholarly journals Data Downloading on the Sparse Coverage-Based Wireless Networks

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Helal Chowdhury ◽  
Janne Lehtomäki ◽  
Juha-Pekka Mäkelä ◽  
Sastri Kota
Keyword(s):  
Wireless Networks ◽  
Wireless Communication ◽  
Communication Networks ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Access Point ◽  
Wireless Communication Networks ◽  
High Data ◽  
Distance Relationship ◽  
The Impact

Infostation, hotspot, and drive-thru internet are examples of sparse coverage-based wireless networks. These wireless communication networks provide low-cost, delay insensitive high data rate services intermittently with discontinuous coverage. Radio propagation parameters, velocity of the user, distance between the user, and access point are the key factors that affect the throughput and the amount of information downloaded from such sparse coverage-based wireless networks. To evaluate the performance of such wireless communication networks analytically the impact of above mentioned factors can be modeled with simplified relationship model such as received signal strength versus distance or signal to noise ratio versus throughput. In the paper, we exploit the relationship between throughput and distance and develop two throughput distance relationship models to evaluate the performance of multirate wireless networks. These two throughput distance relationship models are used in calculation of average throughput as well as downloaded file size. Numerical values are presented for the IEEE 802.11n standard. The numerical results verify that the new proposed technique can be used as an alternative to the simulations to evaluate the performance of sparse coverage-based wireless networks.

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