Sensor Networks In Industrial Environments Research Articles

Experimental Assessment of IEEE 802.15.4e LLDN Mode Using COTS Wireless Sensor Network Nodes

The use of Wireless Sensor Networks in industrial environments imposes critical requirements such as low latency, high reliability, and robustness. To address these constraints, the IEEE 802.15 Task Group 4e developed the amendment IEEE 802.15.4e with three new MAC operation modes: TSCH, DSME, and LLDN. This paper aims to assess the feasibility of implementing the LLDN operation mode in low-cost commercial nodes and their capacity to meet industrial applications’ timing and reliability requirements. LLDN services were implemented in COTS nodes using C programming language with Atmel provided stacks. In order to validate this implementation, a set of experimental scenarios was conducted and the measurement results were compared to simulation results available in the state of the art.

The impact of error control schemes on lifetime of energy harvesting wireless sensor networks in industrial environments

Due to the harsh channel conditions of the industrial environments, the data transmission over the wireless channel suffers from erroneous packets. The energy consumption of error control schemes is of great importance for battery-limited Wireless Sensor Networks (WSNs) in industrial environments. In this paper, the lifetime analysis of error control schemes, i.e., Automatic Repeat Request (ARQ), Forward Error Correction (FEC) and Hybrid ARQ (HARQ), is presented under different industrial environment channel conditions. Furthermore, the impact of energy harvesting methods on the network lifetime is investigated. A novel Mixed Integer Programming (MIP) framework is developed to maximize the network lifetime while meeting application reliability. Performance results show that utilizing HARQ-II error control scheme for Mica2 and BCH(31,21,5) for Telos improves the network lifetime while meeting the desired application reliability rate.

A three-tier scheme for sybil attack detection in heterogeneous IWSN

Industrial wireless sensor network is a new application of wireless sensor network in the field of industry in recent years. However, IWSN may be subject to different attacks and security risks, among which the Sybil attack is the most harmful type of base attack. According to the characteristics of wireless sensor networks in industrial environment, a new three-tier detection scheme is proposed. In the first-level, all common nodes and Sybil nodes were detected by RSSI-based quadratic difference method. In the second layer, the residual energy-based method is used to continue the detection of the nodes that have been detected in the first-level. The detection of first and second-level high-energy nodes is finally completed by the base station. The simulation results show that our proposed scheme significantly improves network lifetime and effectively improve the detection rate of Sybil nodes.

Evaluating Bluetooth Low Energy Suitability for Time-Critical Industrial IoT Applications

In recent years, integration of wireless sensor networks in industrial environments has greatly increased. With this trend, new fields such as industrial IoT have arisen, which in turn have opened the doors to new possibilities that are shaping the future of industrial automation. In contrast to regular wireless networks, however, industrial applications of WSN are characterized for being time-critical systems with highly stringent requirements that challenge all available technologies. Because of its ultra-low energy properties, compatibility with most mobile units, reduced production costs, robustness and high throughput, Bluetooth low energy (BLE) is a potential candidate for these settings. This article explores the potential of BLE of meeting the real-time demands found in the domain of industrial process automation and industrial IoT. In order to evaluate the suitability of the protocol for these scenarios, the effect of adaptations in the retransmission scheme on the reliability and timeliness performance are thoroughly studied. Three retransmission schemes are evaluated and simulation results proved that by optimally modifying the BLE retransmission model, a maximum delay below 46 ms and a packet loss rate in the order of 10^{-5} can be obtained, enabling BLE to fulfill the requirements of even the most demanding cases within the considered range of applications.

The Impact of Temperature on Outdoor Industrial Sensornet Applications

Wireless sensor networks are being considered for use in industrial process and control environments. Unlike traditional deployment scenarios for sensor networks, in which energy preservation is the main design principle, industrial environments stress worker safety and uninterrupted production. To fulfill these requirements, sensor networks must be able to provide performance guarantees for radio communication. In this paper, we consider as a case study the deployment of a sensornet in an oil refinery in Portugal, where sensor nodes are deployed outdoors and might experience high temperature fluctuations. We investigate how the variations of ambient temperature influence data delivery performance and link quality in low-power radio communications. We also study the impact that specific implementation requirements, such as the ATEX fire-safety regulations, can have on the design of the overall network. Our experiments show that temperature directly affects the communication between sensor nodes, and that significantly less transmission power is required at low temperatures. We further illustrate that it is possible to save up to 16% energy during nights and cold periods of the year, while still ensuring reliable communication among sensor nodes. In view of these experimental results, we elaborate on how the temperature influences both the design and the deployment of wireless sensor networks in industrial environments.

Introduction to Model-based Reliability Evaluation of Wireless Sensor Networks

A high level of reliability is a significant requirement for using wireless sensor networks in industrial environments. Model-based evaluation is usually applied in conventional systems to estimate the reliability. In contrast, for analyzing sensor networks, these methods are hardly tested and proven due to the unique properties of that kind of network. This paper presents a first model-based approach to quantitatively assess the reliability of sensor networks. Based on an abstract model of a sensor network, the degree of detail with respect to the characteristic aspects of sensor networks is increased in a stepwise manner. If network topologies are taken into account, analytical methods fail and the assessment of reliability measures has to be done numerically. Finally, a Monte Carlo Simulation is conducted to also cover dynamics in the topology. In conclusion, this paper shows that, by knowledge of link probabilities and lifetime distributions of single sensor nodes, model-based analysis may be used to estimate reliability measures of sensor networks.