Recent public cooperation between the Federal University of Technology – Parana (UTFPR) and the Toledo Municipality plans to implement the concept of smart cities in this city. In this context, one of the applications under development intends to track the recyclable garbage collector trucks in real time over the Internet. Actually, fleet vehicle tracking is one of the main applications for smart cities. LoRaWAN stands out among network technologies for smart cities due to operating in an open frequency range, covering long distances with low power consumption and low equipment cost. However, the coverage and performance of LoRaWAN is directly affected by both the environment and configuration parameters. In addition, tracking devices must be able to send its coordinates to the Internet even when the vehicle goes through zones where there are obstacles for electromagnetic waves such as elevated buildings or valleys. In this paper we perform experimental investigations to evaluate four LoRaWAN tracking devices, two available out of the box and two assembled and programmed. The behavior of each tracking device is analyzed when moving at a constant speed through three representative urban areas totaling 10.71 km2. The two most efficient tracking devices are analyzed in a stretch of 3.5 km with speeds ranging from 0 to 30 km/h, 0 to 50 km/h and 0 to 100 km/h. Results include a quantitative and qualitative aspects, including the received signal strength indication (RSSI), signal-to-noise ratio (SNR), packet delivery ratio (PDR), and spreading factor (SF) for the received geographic coordinates. As the devices depend on the quality of the signal offered by the network, we also present the results of the development and evaluation of the LoRaWAN network, by planning its coverage throughout the city.
In many countries, water quality monitoring is limited due to the high cost of logistics and professional equipment such as multiparametric probes. However, low-cost sensors integrated with the Internet of Things can enable real-time environmental monitoring networks, providing valuable water quality information to the public. To facilitate the widespread adoption of these sensors, it is crucial to identify which sensors can accurately measure key water quality parameters, their manufacturers, and their reliability in different environments. Although there is an increasing body of work utilizing low-cost water quality sensors, many questions remain unanswered. To address this issue, a systematic literature review was conducted to determine which low-cost sensors are being used for remote water quality monitoring. The results show that there are three primary vendors for the sensors used in the selected papers. Most sensors range in price from US$6.9 to US$169.00 but can cost up to US$500.00. While many papers suggest that low-cost sensors are suitable for water quality monitoring, few compare low-cost sensors to reference devices. Therefore, further research is necessary to determine the reliability and accuracy of low-cost sensors compared to professional devices.
Software-defined networks (SDN) usually rely on a centralized controller, which has limited availability and scalability by definition. Although a solution is to employ a distributed control plane, the main issue with this approach is how to maintain the consistency among multiple controllers. Consistency should be achieved with as low impact on network performance as possible and should be transparent for controllers, without requiring any change of the SDN protocols. In this work, we propose VNF-Consensus, a virtual network function that implements Paxos to ensure strong consistency among controllers of a distributed control plane. In our solution, controllers can perform their control plane activities without having to execute the expensive tasks required to keep consistency. Experimental results are presented showing the cost and benefits of the proposed solution, in particular in terms of low controller overhead. | INTRODUCTIONSoftware-defined networks (SDN) separate the control plane from the data plane, which improves their flexibility, programmability, and management. 1,2 The control plane is usually centralized, consisting of a single controller, while the data plane consists of numerous network devices distributed across the network. While a centralized approach is attractive as it is simpler to operate and manage, it represents a vulnerability as the controller is a single point of failure with a direct impact not only in terms of resilience (i.e., if the controller fails the whole network stops running) but also on performance and scalability 3 (i.e., the single controller has to process all requests from all switches). The solution is to distribute the control plane, employing multiple controllers that share responsibilities. 4 Several different distributed SDN control plane strategies have been proposed. 5,6 Although the advantages of employing multiple controllers should be clear, there is also a cost to pay: in order to employ a distributed control plane it is necessary to employ techniques to guarantee the consistency among the
Redes LPWAN (Low-Power Wide-Area Network) são um tipo de rede sem-fio projetada para cobrir uma extensa área a uma baixa taxa de transferência de bits. Entre as tecnologias LPWAN, o padrão aberto LoRaWAN destaca-se por operar em uma faixa de frequência aberta, atingir um longo alcance, pouco consumo de energia e baixo custo dos equipamentos. Este artigo descreve a implantação e avaliação de uma rede LoRaWAN para apoiar a construção do conceito de cidades inteligentes no município de Toledo/PR. A avaliação considera a qualidade do sinal em diversos pontos do município e confronta os dados obtidos com um modelo de simulação. Também são apresentados o plano para expansão da rede e algumas aplicações em desenvolvimento.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.