2,922 research outputs found
Wireless industrial monitoring and control networks: the journey so far and the road ahead
While traditional wired communication technologies have played a crucial role in industrial monitoring and control networks over the past few decades, they are increasingly proving to be inadequate to meet the highly dynamic and stringent demands of today’s industrial applications, primarily due to the very rigid nature of wired infrastructures. Wireless technology, however, through its increased pervasiveness, has the potential to revolutionize the industry, not only by mitigating the problems faced by wired solutions, but also by introducing a completely new class of applications. While present day wireless technologies made some preliminary inroads in the monitoring domain, they still have severe limitations especially when real-time, reliable distributed control operations are concerned. This article provides the reader with an overview of existing wireless technologies commonly used in the monitoring and control industry. It highlights the pros and cons of each technology and assesses the degree to which each technology is able to meet the stringent demands of industrial monitoring and control networks. Additionally, it summarizes mechanisms proposed by academia, especially serving critical applications by addressing the real-time and reliability requirements of industrial process automation. The article also describes certain key research problems from the physical layer communication for sensor networks and the wireless networking perspective that have yet to be addressed to allow the successful use of wireless technologies in industrial monitoring and control networks
PACE: Simple Multi-hop Scheduling for Single-radio 802.11-based Stub Wireless Mesh Networks
IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC.
PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned
An Overview of Mobile Ad Hoc Networks for the Existing Protocols and Applications
Mobile Ad Hoc Network (MANET) is a collection of two or more devices or nodes
or terminals with wireless communications and networking capability that
communicate with each other without the aid of any centralized administrator
also the wireless nodes that can dynamically form a network to exchange
information without using any existing fixed network infrastructure. And it's
an autonomous system in which mobile hosts connected by wireless links are free
to be dynamically and some time act as routers at the same time, and we discuss
in this paper the distinct characteristics of traditional wired networks,
including network configuration may change at any time, there is no direction
or limit the movement and so on, and thus needed a new optional path Agreement
(Routing Protocol) to identify nodes for these actions communicate with each
other path, An ideal choice way the agreement should not only be able to find
the right path, and the Ad Hoc Network must be able to adapt to changing
network of this type at any time. and we talk in details in this paper all the
information of Mobile Ad Hoc Network which include the History of ad hoc,
wireless ad hoc, wireless mobile approaches and types of mobile ad Hoc
networks, and then we present more than 13 types of the routing Ad Hoc Networks
protocols have been proposed. In this paper, the more representative of routing
protocols, analysis of individual characteristics and advantages and
disadvantages to collate and compare, and present the all applications or the
Possible Service of Ad Hoc Networks.Comment: 24 Pages, JGraph-Hoc Journa
Development of a multi-hop wireless sensor system for the dynamic event monitoring of civil infrastructure and its extension for seismic response monitoring
The dynamic response of civil infrastructures under transient dynamic events is of particular interests for structural engineers, because these event-induced responses usually provide useful insights into the real dynamic behavior of civil infrastructures under extreme conditions. Monitoring these dynamic event induced vibrations are among the most frequently conducted measurements and experiments in the structural engineering field, and a cheaper, simpler and more flexible monitoring system is always under pursuit of civil engineers. One particular such request comes from the seismic response monitoring applications. Seismic response monitoring for general civil infrastructure is critical in high-risk earthquake areas like Japan. It contributes to earthquake safety by providing quantitative measurement that enables improved understanding and predictive modeling of the earthquake response of these engineered systems. However, due to the limitations of the current monitoring systems, such seismic response records of general civil infrastructure are usually not available. Therefore, this research describes a novel development of an autonomous dynamic event monitoring system using Wireless Smart Sensor Network(WSSN), which is further extended to support the purpose of long-term seismic response monitoring. This developed WSSN monitoring system is portable and low-cost, it has a potential to provide long-term seismic response monitoring for a wide range of civil infrastructure. This system can run on existing power sources readily available in common civil infrastructure and thus is able to perform long-term continuous sensing as demanded by the seismic response monitoring applications. A quick and stable event detection method is developed to trigger the recording of the complete seismic response and also eliminate possible false alerts caused by unexpected disturbance. Long-term network-wide time synchronization is guaranteed by a customized long-term Flooding Time Synchronization Protocol(FTSP) so that the all sensor nodes in the network can provide consistent time records of their captured seismic response. An efficient multi-hop service module is also incorporated into the system to disseminate commands and accommodate the need of collecting data in a reliable and prompt manner after major earthquakes, the integrated multi-hop data collection protocol provides a theoretically optimum data collection efficiency. Various experiments have been done to validate the developed programs. Suggestions are also given towards the final realization of successful long-term implementation of the developed monitoring system.報告番号: ; 学位授与年月日: 2012-09-27 ; 学位の種別: 修士 ; 学位の種類: 修士(工学) ; 学位記番号: ; 研究科・専攻: 工学系研究科社会基盤学専
Performance Analysis of On-Demand Routing Protocols in Wireless Mesh Networks
Wireless Mesh Networks (WMNs) have recently gained a lot of popularity due to their rapid deployment and instant communication capabilities. WMNs are dynamically self-organizing, self-configuring and self-healing with the nodes in the network automatically establishing an adiej hoc network and preserving the mesh connectivity. Designing a routing protocol for WMNs requires several aspects to consider, such as wireless networks, fixed applications, mobile applications, scalability, better performance metrics, efficient routing within infrastructure, load balancing, throughput enhancement, interference, robustness etc. To support communication, various routing protocols are designed for various networks (e.g. ad hoc, sensor, wired etc.). However, all these protocols are not suitable for WMNs, because of the architectural differences among the networks. In this paper, a detailed simulation based performance study and analysis is performed on the reactive routing protocols to verify the suitability of these protocols over such kind of networks. Ad Hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Dynamic MANET On-demand (DYMO) routing protocol are considered as the representative of reactive routing protocols. The performance differentials are investigated using varying traffic load and number of source. Based on the simulation results, how the performance of each protocol can be improved is also recommended.Wireless Mesh Networks (WMNs), IEEE 802.11s, AODV, DSR, DYMO
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