Análise de desempenho baseada em simulação de redes WirelessHART

This dissertation describes the implementation of a WirelessHART networks simulation module for the Network Simulator 3, aiming for the acceptance of both on the present context of networks research and industry. For validating the module were imeplemented tests for attenuation, packet error rate, information transfer success rate and battery duration per station

Contribuições em escalonamento e análise de desempenho de redes WirelessHART

Wireless Communication is a trend in the industrial environment nowadays and on this trend, we can highlight the WirelessHART technology. In this situation, it is natural the search for new improvements in the technology and such improvements can be related directly to the routing and scheduling algorithms. In the present thesis, we present a literature review about the main specific solutions for Routing and scheduling for WirelessHART. The thesis also proposes a new scheduling algorithm called Flow Scheduling that intends to improve superframe utilization and flexibility aspects. For validation purposes, we develop a simulation module for the Network Simulator 3 (NS-3) that models aspects like positioning, signal attenuation and energy consumption and provides an link individual error configuration. The module also allows the creation of the scheduling superframe using the Flow and Han Algorithms. In order to validate the new algorithms, we execute a series of comparative tests and evaluate the algorithms performance for link allocation, delay and superframe occupation. In order to validate the physical layer of the simulation module, we statically configure the routing and scheduling aspects and perform reliability and energy consumption tests using various literature topologies and error probabilities.

Contribuições em escalonamento e análise de desempenho de redes WirelessHART

Wireless Communication is a trend in the industrial environment nowadays and on this trend, we can highlight the WirelessHART technology. In this situation, it is natural the search for new improvements in the technology and such improvements can be related directly to the routing and scheduling algorithms. In the present thesis, we present a literature review about the main specific solutions for Routing and scheduling for WirelessHART. The thesis also proposes a new scheduling algorithm called Flow Scheduling that intends to improve superframe utilization and flexibility aspects. For validation purposes, we develop a simulation module for the Network Simulator 3 (NS-3) that models aspects like positioning, signal attenuation and energy consumption and provides an link individual error configuration. The module also allows the creation of the scheduling superframe using the Flow and Han Algorithms. In order to validate the new algorithms, we execute a series of comparative tests and evaluate the algorithms performance for link allocation, delay and superframe occupation. In order to validate the physical layer of the simulation module, we statically configure the routing and scheduling aspects and perform reliability and energy consumption tests using various literature topologies and error probabilities.

第十四章 WIA-PA:用于过程自动化的工业无线网络系统结构与通信规范

概要介绍工业无线网络的标准化进程,详细介绍了用于过程自动化的工业无线网络WIA规范的网络构成、拓扑结构、协议体系和关键技术,并将WIA-PA与WirelessHART、ISASP100两大工业无线标准进行了比较分析。

无线HART网络管理器的研究与实现

工业无线网络技术是继现场总线之后，工业控制领域的又一个热点技术，是降低工业测控系统成本、提高工业测控系统应用范围的革命性技术。无线HART规范作为第一个开放的工业无线网络国际标准，在满足工业应用苛刻的可靠性、实时性和安全性等关键需求的同时，还提供良好的向后兼容性，具有广阔的应用前景。网络管理器是无线HART网络的核心设备，是无线HART规范研究与开发的重点和难点。 本文在对工业无线网络技术、无线HART协议及其关键技术、无线HART网络管理器进行详细总结的基础上，从核心算法、软件的设计与实现等方面对无线HART网络管理器进行了研究，取得以下成果： (1)提出了一种基于有向图的独立多路径路由算法。算法包括路由发现和路由计算两个过程。路由发现中提出了基于负载均衡和信号强度的邻居过滤，以及邻居冗余等机制，保证了网络可靠性，降低了算法开销。路由计算中提出了基于双向链路筛选的拓扑构建，基于改进Dijkstra算法的最短路径生成，以及基于启发式搜索的独立多路径筛选等机制，满足了工业应用可靠、实时、低开销和低能耗等性能要求。 (2)提出了基于均衡搜索的通信资源分配算法。采用动态的信道黑名单技术，提高了网络的可靠性；保证所分资源均匀分布在搜索空间中，提高了算法应对网络动态性的能力；与主通信资源反序的冗余通信资源搜索过程，使得不同节点的资源均衡，保证了通信资源分配的公平性。此外，该算法还具有轻型、实时等优点。 (3)设计和实现了无线HART网络管理器软件。针对网络管理器功能复杂，性能要求高等问题，本文采用模块化软件设计方法设计和实现了无线HART网络管理器软件，并将其应用于辽宁省一大型纸业有限公司75吨流化床温度与压力监测系统中。网络管理器长期稳定运行、性能良好的事实表明了设计与实现的合理性。

A traffic differentiation add-on to the IEEE 802.15.4 protocol: implementation and experimental validation over a real-time operating system

The IEEE 802.15.4 is the most widespread used protocol for Wireless Sensor Networks (WSNs) and it is being used as a baseline for several higher layer protocols such as ZigBee, 6LoWPAN or WirelessHART. Its MAC (Medium Access Control) supports both contention-free (CFP, based on the reservation of guaranteed time-slots GTS) and contention based (CAP, ruled by CSMA/CA) access, when operating in beacon-enabled mode. Thus, it enables the differentiation between real-time and best-effort traffic. However, some WSN applications and higher layer protocols may strongly benefit from the possibility of supporting more traffic classes. This happens, for instance, for dense WSNs used in time-sensitive industrial applications. In this context, we propose to differentiate traffic classes within the CAP, enabling lower transmission delays and higher success probability to timecritical messages, such as for event detection, GTS reservation and network management. Building upon a previously proposed methodology (TRADIF), in this paper we outline its implementation and experimental validation over a real-time operating system. Importantly, TRADIF is fully backward compatible with the IEEE 802.15.4 standard, enabling to create different traffic classes just by tuning some MAC parameters.

Uma metodologia para modelagem e avaliação da dependabilidade de redes industriais sem fio

Ensuring the dependability requirements is essential for the industrial applications since faults may cause failures whose consequences result in economic losses, environmental damage or hurting people. Therefore, faced from the relevance of topic, this thesis proposes a methodology for the dependability evaluation of industrial wireless networks (WirelessHART, ISA100.11a, WIA-PA) on early design phase. However, the proposal can be easily adapted to maintenance and expansion stages of network. The proposal uses graph theory and fault tree formalism to create automatically an analytical model from a given wireless industrial network topology, where the dependability can be evaluated. The evaluation metrics supported are the reliability, availability, MTTF (mean time to failure), importance measures of devices, redundancy aspects and common cause failures. It must be emphasized that the proposal is independent of any tool to evaluate quantitatively the target metrics. However, due to validation issues it was used a tool widely accepted on academy for this purpose (SHARPE). In addition, an algorithm to generate the minimal cut sets, originally applied on graph theory, was adapted to fault tree formalism to guarantee the scalability of methodology in wireless industrial network environments (< 100 devices). Finally, the proposed methodology was validate from typical scenarios found in industrial environments, as star, line, cluster and mesh topologies. It was also evaluated scenarios with common cause failures and best practices to guide the design of an industrial wireless network. For guarantee scalability requirements, it was analyzed the performance of methodology in different scenarios where the results shown the applicability of proposal for networks typically found in industrial environments

Ferramentas para análise de ativos em redes industriais weirelessHART

Nowadays wireless communication has emerged as a tendency in industry environments. In part this interest is due to the ease of deployment and maintenance, which dispenses sophisticated designs and wired infrastructure (which in industrial environment often prohibitively expensive) besides enabling the addition of new applications when compared to their wired counterparts. Despite its high degree of applicability, an industrial wireless sensor network faces some challenges. One of the most challenging problems are its reliability, energy consumption and the environment interference. In this dissertation will discuss the problem of asset analysis in wireless industrial networks for the WirelessHART standard by implementing a monitoring system. The system allows to carry out various activities of independent asset management manufacturers, such as prediction of battery life, maintenance, reliability data, topology, and the possibility of creating new metrics from open and standardized development libraries. Through the implementation of this tool is intended to contribute to integration of wireless technologies in industrial environments.

Ferramenta para avaliação e inferência de parâmetros de redes industriais sem fio

Wireless sensor networks (WSN) have gained ground in the industrial environment, due to the possibility of connecting points of information that were inaccessible to wired networks. However, there are several challenges in the implementation and acceptance of this technology in the industrial environment, one of them the guaranteed availability of information, which can be influenced by various parameters, such as path stability and power consumption of the field device. As such, in this work was developed a tool to evaluate and infer parameters of wireless industrial networks based on the WirelessHART and ISA 100.11a protocols. The tool allows quantitative evaluation, qualitative evaluation and evaluation by inference during a given time of the operating network. The quantitative and qualitative evaluation are based on own definitions of parameters, such as the parameter of stability, or based on descriptive statistics, such as mean, standard deviation and box plots. In the evaluation by inference uses the intelligent technique artificial neural networks to infer some network parameters such as battery life. Finally, it displays the results of use the tool in different scenarios networks, as topologies star and mesh, in order to attest to the importance of tool in evaluation of the behavior of these networks, but also support possible changes or maintenance of the system.