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PL
W artykule opisano innowacyjną metodę lokalizowania obiektów dla potrzeb Internetu rzeczy (IoT). Przedstawiono matematyczną analizę metody. Opisano również wyniki kompleksowych badań symulacyjnych efektywności pracy zaproponowanej metody dla wybranych parametrów radiowej sieci sensorowej.
EN
The paper proposes an innovative method of locating objects for the Internet of Things (IoT). The mathematical analysis of the method is presented. The results of complex simulation studies on the efficiency of the proposed method for various selected system parameters of the sensor network are described.
EN
The paper presents a circuit structure that can be used for powering an IoT (Internet of Things) sensor node and that can use energy just from its surroundings. The main advantage of the presented solution is its very low cost that allows mass applicability e.g. in the IoT smart grids and ubiquitous sensors. It is intended for energy sources that can provide enough voltage but that can provide only low currents such as piezoelectric transducers or small photovoltaic panels (PV) under indoor light conditions. The circuit is able to accumulate energy in a capacitor until a certain level and then to pass it to the load. The presented circuit exhibits similar functionality to a commercially available EH300 energy harvester (EH). The paper compares electrical properties of the presented circuit and the EH300 device, their form factors and costs. The EH circuit’s performance is tested together with an LTC3531 buck-boost DC/DC converter which can provide constant voltage for the following electronics. The paper provides guidelines for selecting an optimal capacity of the storage capacitor. The functionality of the solution presented is demonstrated in a sensor node that periodically transmits measured data to the base station using just the power from the PV panel or the piezoelectric generator. The presented harvester and powering circuit are compact part of the sensor node’s electronics but they can be also realized as an external powering module to be added to existing solutions.
EN
Design of the MAC protocol is crucial in all wireless sensor networks (WSNs) due to its influence on the performance of the transceiver, i.e. the most energy-consuming component of each sensor node. A mechanism known as “carrier sense multiple access with collision avoidance” (CSMA/CA) is used for accessing the wireless channel in the IEEE 802.15.4 standard-based MAC protocol in order to avoid collisions between the network’s communicating nodes. CSMA/CA relies on two clear channel assessments (CCA=2) for checking the status of the channel. In this paper, we develop an additional CCA algorithm for the two scenarios encountered in star topology-enabled WSNs. Next, we investigate the impact of an additional clear channel assessment (CCA=3) on performance in IEEE 802.15.4. We develop a Markov chain model for the proposed methodology, and validate it using Matlab. Simulation results show that there is a significant improvement of performance metrics in the IEEE 802.15.4 standard-based MAC protocol with an additional CCA.
EN
Wireless sensor networks are typically operated on batteries. Therefore, in order to prolong network lifetime, an energy efficient routing algorithm is required. In this paper, an energy-aware routing protocol for the co-operative MIMO scheme in WSNs (EARPC) is presented. It is based on an improved cluster head selection method that considers the remaining energy level of a node and recent energy consumption of all nodes. This means that sensor nodes with lower energy levels are less likely to be chosen as cluster heads. Next, based on the cooperative node selection in each cluster, a virtual MIMO array is created, reducing uneven distribution of clusters. Simulation results show that the proposed routing protocol may reduce energy consumption and improve network lifetime compared with the LEACH protocol.
EN
Wireless Sensor Network finds its extensive use in healthcare applications for the transfer of time-critical data through wireless connectivity. The primary cause of network failure is the transfer of time-critical multimedia data. The article presents a new dfferentiated service modelsupported (DSM) cluster-based routing in wireless sensor networks (WSNs) that overcomes the above issue. DSM prioritizes the transfer of dfferent flow types based on packet type and packet size. The employment of computational offlading minimizes delay for critical and small-sized data packets and by carrying out data reduction of large-sized packets at proxy server. It outperforms the existing protocols in terms of energy efficiency, throughput, and reliability by prioritizing the transfer of time-critical health application data.
EN
The 6TiSCH communication stack enables IPv6 networking over the TSCH (Time Slotted Channel Hopping) mode of operation defined in IEEE 802.15.4. Lately it became an attractive solution for Low power and Lossy Networks (LLNs), suitable for Industrial Internet (IIoT) applications. This article introduces a credible energy consumption model for the 6TiSCH network nodes, operating in the 863-870 MHz band. It presents the analysis leading to the construction of the model as well as verification through experimental measurements which showed 98% accuracy in determining power consumption for two different network topologies. The article includes reliable battery lifetime predictions for transit and leaf nodes along with other parametric study results.
PL
Stężenia i natężenia czynników szkodliwych w środowisku pracy muszą być badane i oceniane pod kątem powodowanych dla pracowników zagrożeń. W warunkach zmiennych parametrów środowiska pracy wykrywanie potencjalnych zagrożeń i szybkie podejmowanie działań zmierzających do ograniczenia narażenia pracowników jest możliwe na podstawie ciągłego monitoringu parametrów środowiska pracy. Do tego celu mogą być wykorzystanie bezprzewodowe sieci sensorowe. W artykule omówiono strukturę i oraz główne zagadnienia opracowywanej w CIOP-PIB sieci sensorowej do monitorowania środowiska pracy i ostrzegania pracowników o zagrożeniach. Przedstawiono zastosowaną metodę lokalizacji ostrzeganego pracownika w obrębie sieci sensorowej, a także wyniki badań mocy sygnału radiowego, na bazie których funkcjonuje ta metoda.
EN
Concentrations and intensities of harmful factors in the work environment must be tested and assessed for hazards caused to employees. In conditions of changing parameters of the working environment, detection of potential threats and quick action to reduce employee exposure is possible based on the continuous monitoring of working environment parameters. Wireless sensor networks can be used for this purpose. The article discusses the structure and main issues of the sensor network being developed at CIOP-PIB to monitor the work environment and warn employees about hazards. The method used to locate the warned employee with in the sensor network was presented, as well as the results of radio signal strength measurements, on which this method works.
EN
We present a software platform for designing and testing wireless networks of sensors and actuators (WSNs). The platform consists of three components: an operating system for small-footprint microcontrollers (dubbed PicOS), a software development kit (SDK) amounting to a C-based, event-oriented (reactive) programming language, and a virtual execution platform (VUE2 ) capable of emulating complete deployment environments for WSNs and thus facilitating their rapid development.1 Its most recent incarnation introduced in the present paper is a component of the WSN lab being currently set up at Vistula in collaboration with Olsonet Communications Corporation. 2 We highlight the platform’s most interesting features within the context of a production WSN installed at independent-living facilities.
EN
The paper presents a robust QoS centric routing protocol for mission-critical communication over mobile Wireless Sensor Networks (CL-mWSN) that exploits dynamic network states from the different layers of the IEEE 802.15.4 protocol stack to make the routing decision. The CL-mWSN protocol exploits three key layers: application layer, network layer and MAC layer. It exhibits proactive network and node table management, service differentiation, fair resource scheduling and congestion detection, avoidance at the network layer, as well as dynamic link quality estimation and packet injection rate estimation at the MAC layer to assess its candidature as the best forwarding node for QoS-centric mission-critical communication. Simulation reveals that the proposed routing model exhibits higher throughput, minimum loss and deadline miss ratio that augments QoS provision in mobile WSNs.
10
Content available remote Using relay nodes in wireless sensor networks: a review
EN
To extend the lifetime of wireless sensor networks, recent works suggest the use of relay nodes. This paper surveys and examines representative approaches dealing with relay nodes deployment. It also discusses their shortcomings and presents a comparative study. Additionally, this paper provides a set of remarks and recommendations to improve the usage of relay nodes in wireless sensor networks and highlights open issues that need further investigation.
11
Content available remote Remote programming and reconfiguration system for embedded devices
EN
This article presents a concept of a system which can be utilized as a remote management add-on for embedded devices. It can be applied to resource-constrained wireless sensors and IoT nodes based on a general purpose microcontroller unit or a field programmable gate array (FPGA) chip. The proposed solution facilitates remote firmware update, management, and operation monitoring. Thanks to the utilization of standard protocols and interfaces, the proposed system is very flexible and it can be easily customized for multiple modern microcontrollers or programmable logic chips. The presented system can be an efficient solution for fast prototyping and it can be an alternative to a time-consuming process of bootloader development for ad hoc devices. It can also be applied to remote laboratory access for educational purposes. A proof of concept prototype implementation has been successfully developed and evaluated. The implementation is available on a free license and utilizes a commonly available and inexpensive hardware platform.
12
Content available remote On coverage of 3D terrains by wireless sensor networks
EN
The coverage of a Region of Interest (RoI), that must be satisfied when deploying a Wireless Sensor Network (WSN), depends on several factors related not only to the sensor nodes (SNs) capabilities but also to the RoI topography. This latter has been omitted by most previous deployment approaches, which assume that the RoI is 2D. However, some recent WSNs deployment approaches dropped this unrealistic assumption. This paper surveys the different models adopted by the state-of-the-art deployment approaches. The weaknesses that need to be addressed are identified and some proposals expected to enhance the practicality of these models are discussed.
PL
Burzliwy rozwój technologii informatycznych pozwala na pozyskiwanie, przetwarzanie i automatyczną analizę wielkich ilości danych diagnostycznych. Umożliwia to realizację optymalnych pod względem efektywności i kosztu strategii utrzymania infrastruktury kolejowej. Centrum Diagnostyki PKP Polskie Linie Kolejowe S.A. utrzymuje obszerny zbiór danych diagnostycznych i podejmuje działania ku przekształceniu go w wydajną bazę do działań analitycznych, zgodnie ze współczesnymi trendami, znanymi pod hasłem Big Data Analytics. Częścią aktywności w tym zakresie jest pozyskiwanie nowych źródeł danych diagnostycznych. Przykładem jest projekt pilotażowy wdrożenia sieci autonomicznych sensorów bezprzewodowych do monitorowania temperatury szyn. Artykuł opisuje podjęte i planowane działanie wraz z koniecznym kontekstem technologicznym.
EN
Fierce development of IT sector allows for an effective acquisition, processing and automatic analysis of large volumes of diagnostic data. This in turn brings in the possibility of implementing an optimal strategy for railway infrastructure maintenance in terms of both effectiveness and operational costs. The Center for Diagnostics, PKP Polskie Linie Kolejowe S.A. maintains a large database of diagnostic data and puts an effort toward transforming this data set into effective and consistent platform of data analysis according to current trend called Big Data Analytics. A part of an effort in this field is extending the database with new diagnostic data sets. The recent example of such activity is a drive test project of implementing a wireless sensor network for rail temperature monitoring. The undertaken and planned initiatives along with necessary technological context have been described in the paper.
PL
Sieci bezprzewodowe opierające się na standardzie IEEE802.15.4e-TSCH zdobywają popularność w dziedzinie Przemysłowego Internetu Rzeczy. TSCH (ang. Time Slotted Channel Hopping) pozwala na osiągnięcie wysokiego stopnia niezawodności łącza odpowiadającej zastosowaniom przemysłowym. Standard jednakże nie definiuje działania planisty, co jest obecnie tematem prac wielu ośrodków badawczych. W naszym artykule przedstawiamy rozwiązanie problemu maksymalizacji przepustowości w sieciach TSCH z założeniem zerowej domeny kolizyjnej. Celem uzyskania rozwiązania optymalnego, przydział zasobów łącza został rozwiązany jako problem programowania liniowego. Proponujemy ponadto autorski algorytm heurystyczny, harmonogramujący transmisje w sposób centralny. W pracy zaprezentowaliśmy jego działanie oraz zestawiliśmy wyniki symulacji z rozwiązaniem optymalnym.
EN
Wireless sensor networks incorporating the IEEE802.15.4e-TSCH standard are recognized as a reliable solution in the field of Industrial Internet of Things. TSCH (Time Slotted Channel Hopping) allows achieving a high degree of link reliability which corresponds to industrial applications. The standard, however, does not define how the scheduler operates. This open issue is one of the trending topic of many research centers. In our article, we put forward a solution to the problem of throughput maximization in TSCH networks assuming a zero collision domain. In our article the issue of resource allocation has been described as a linear programming problem in order to obtain an optimal solution. We also propose an original heuristic algorithm that schedules transmissions in a centralized way. A comparative study of simulation results is presented.
PL
W artykule przedstawiono podsumowanie parametrów współczesnych, komercyjnych modułów nawigacji satelitarnej oraz przeanalizowano możliwość ich wykorzystania do synchronizacji czasu w bezprzewodowych sieciach czujników lub urządzeniach typu IoT. Szczególny nacisk położono na porównanie z sieciowymi protokołami synchronizacji czasu oraz analizę zużycia energii przez moduły.
EN
In the paper authors summarize parameters of modern, commercially available satellite navigation modules and their potential to be used as time reference source in wireless sensor networks or IoT devices. In particular comparison to network time synchronization protocols and analysis of modules’ power consumption is made.
EN
The failure rate of sensor nodes in Heterogeneous Wireless Sensor Networks is high due to the use of low battery-powered sensor nodes in a hostile environment. Networks of this kind become non-operational and turn into disjoint segmented networks due to large-scale failures of sensor nodes. This may require the placement of additional highpower relay nodes. In this paper, we propose a network partition recovery solution called Grey Wolf, which is an optimizer algorithm for repairing segmented heterogeneous wireless sensor networks. The proposed solution provides not only strong bi-connectivity in the damaged area, but also distributes traffic load among the multiple deployed nodes to enhance the repaired network’s lifetime. The experiment results show that the Grey Wolf algorithm offers a considerable performance advantage over other state-of-the-art approaches.
EN
ZigBee networks, with their characteristics of high availability, low power consumption and cost-effective devices, are perfectly appropriate to construct Wireless Sensor Networks (WSNs). Also, the natures of WSN listed above bring significant benefits over traditional communication networks used in smart home systems. A smart home system is meant to improve the quality of life through offering various automated, interactive and comfortable services, such as sensing and communicating the family member’s health information with their doctors, or remotely controlling the appliances via cellular phones, emails etc. These critical services make the security of personal privacy and the authority of control commands vital issues in Smart Home environments. While the smart home system suffer from many attacks, the security of the smart home system become an important and hard problem. And the authentication is the first parclose to the security of the system. However, according to our analysis, most system fail to achieve the authentication between the user and the device, Which leading to the compromise of the whole system. In this paper, we analyze the authentication challenges between the user the device in WSNs and in smart home Systems. To thoroughly detect, defense and foresee the authentication vulnerabilities existing in smart home networks, we proposed a security evaluation technique based on attack graph generation. We discuss the distinction between the attack graphs deployed in traditional networks and in smart home networks. Furthermore, we apply this technique into an experiment, and the results prove its practicality. And we then suggest a widely used protocol to the smart home authentication system.
PL
W artykule przedstawiono projekt, wykonanie i badania eksperymentalne systemu energooszczędnych, bezprzewodowych modułów pomiarowych, umożliwiających synchroniczny pomiar sygnałów z kilku oddalonych miejsc. Zaproponowano okresowy sposób transmisji pakietów, wykorzystujący zdefiniowane szczeliny czasowe oraz wprowadzanie modułu pomiarowego w stan obniżonego poboru mocy. Opracowany system pracuje w paśmie ISM 2,4 GHz, może transmitować pakiety danych jednocześnie z czterech modułów z częstotliwością 20 H z. Przy zasilaniu z baterii typu CR2032 (3 V) średnie zużycie prądu wynosi ok. 760 μA. Pakietowa stopa błędów dla szybkości modulacji 1 Mb/s, mocy nadajnika +4 dBm i 50 bajtów transmitowanych danych jest mniejsza niż 0,001.
EN
The article presents design, implementation and experimental research of the energy-efficient wireless sensor nodes. These nodes enable synchronous of signals measurement from several remote locations. A periodic method of packet transmission was proposed, using defined time slots and entering the nodes into a sleep state. The wireless system operates in the 2.4 GHz ISM band. It can transmit data packets simultaneously from four nodes with a 20 Hz frequency rate. When supplied from CR2032 (3 V) batteries, the average power consumption is approx. 760 μA. The packet error rate, for the 1 Mbps radio data modulation, +4 dBm Tx power and transmitted of 50 bytes, is less than 0.001.
EN
The Internet of Things (IoT) paradigm is referring to the underlying constituents of the 4th Industrial Revolution that will also affect the use of the internet in industrial production in the future. More than 50 billion smart devices will be able to communicate with each other and internet services over the increasing network capabilities of wireless sensor networks nodes on IoT applications in the next ten years. One of the leading production areas using IoT within wireless sensor networks is precision agricultural practices. In this study, a new sensor node design, which includes ambient light and temperature sensors employing Bluetooth Low Energy (BLE) communication protocol, is used as an IoT application. Subsequent to this, sensor node power consumption and management cost was investigated. The experimental results show that the developed sensor node lifetime is about 8 years and the total cost of nodes and gateway model is under $50 per year per 0.1 hectare.
PL
W artykule przedstawiono zbiór mechanizmów pozwalających na wykrycie ataków na protokół routingu RPL dla sieci sensorowych. Dzięki obserwacji i weryfikacji zarówno zależności czasowych pomiędzy poszczególnymi komunikatami, jak i zawartości tych komunikatów możliwa jest ocena węzłów sąsiednich, jako zachowujące się poprawnie, niepoprawnie lub podejrzanie. Dzięki takiej klasyfikacji oraz odpowiednim reakcjom można wykryć zagrożenia i znacznie zminimalizować skutki popularnych ataków.
EN
The article presents the mechanisms for detecting the RPL routing protocol attacks in 6LoWPAN-based sensor networks. Combination of time-dependent events analysis and routing messages verifications enables the sensors to appropriately classify their neighbors and to react on the popular attacks.
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