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The overall objective of the research is to summarize tactical considerations, resulting from terrain and weather analysis, to support the preparation, planning and execution of subterranean operations. The study used the Grounded Theory for collection, analysis, and systematic treatment of data. The main data sources for the study consisted of purposive sampling from operations in subterranean systems...
An increasing number of IEEE 802.15.4-based protocols has emerged over the last few years targeting industrial automation applications. One motivation for this is the IEEE 802.15.4 support of low-power communications, which enables deployments with stringent autonomy requirements (e.g., Wireless Sensor Networks). However, this feature may well be responsible for a degraded performance in scenarios...
Low-power wireless communication protocols have been shown to experience a significant timeliness and reliability degradation under certain interference profiles. Provided that this impairment has hindered their wide adoption in demanding real-time scenarios, the Wireless Flexible Time Triggered (WFTT) protocol has been recently proposed targeting applications with stringent timeliness requirements...
Nowadays, as in many other domains, wireless communications are a hot topic in Industrial Automation. Nevertheless, their deployment in real-time applications has been mostly conducted in tightly controlled environments, given the potential threats posed by Denial of Service attacks resulting from interference. Hence, the support of communications providing timeliness guarantees in open wireless environments...
The adoption of established fieldbus technologies in demanding scenarios has been supported by the lack of reliability of wireless communications, for example, under the influence of interference. In the last few years, new methods such as channel hoping and blacklisting have been proposed to cope with these vulnerabilities, but their effectiveness is limited. This paper proposes a wireless protocol...
Wireless communications are being applied in a wide range of scenarios. This paper explores the use of ZigBee to implement a master/multi-slave protocol (FTT-L) supporting a localization system. This protocol as well as its implementation are described throughout the paper and an assessment of several key parameters is conducted. Results are used to derive the delay of a localization round, which...
Wireless communications are being applied in heterogeneous domains ranging from healthcare to industrial manufacturing. However, as wireless channels are highly unreliable, the support of applications having tight hard real-time and fault-tolerance requirements has been provided by dedicated wired communications. Recently, a technique named bandjacking has been evaluated as a feasible solution to...
The flexible time-triggered CAN protocol supports synchronous and asynchronous traffic over a CAN fieldbus. The use of bus and master redundancy is an evolution to the original FTT definition. A protocol supporting multiple buses and masters has been proposed. This paper presents experimental results allowing to assess the timeliness of the communication system. The conclusion is that the system reacts...
This paper presents an upper MAC protocol based on a centralized master multi-slave architecture which is used to coordinate communications among the different type of nodes required for an indoor localization system (ILS) based on IEEE 802.15.4. This protocol works for the non-beacon enabled mode of the referred standard and is used to avoid additive delays in the localization communications. The...
This paper studies the adoption of the ZigBee technology to replace broadcast-based wired communications in automation systems for Health Smart Homes. An analytical study is presented as well as the experimental results validating the derived expressions. Results show that the timeliness of ZigBee broadcast communications, in interference-free environments, can cope with the requirements of home automation...
This paper studies the impact of severe ISM noise interference in IEEE 802.15.4 based location systems, in particular the LOPES project. The architecture and operation of the location system are presented as well as the underneath physical mechanisms supporting the IEEE 802.15.4 noise immunity. A test-bed is proposed and the assessment scenario is described by focusing on the trial parameters. Results...
This paper presents an overview of the challenges in developing health smart homes targeting, in particular, elderly and impaired people. As such, it identifies the current endeavors as well as the main areas of research.
VTPE-hBEB is a protocol suitable to transmit realtime traffic on top of shared Ethernet, enabling the coexistence of specific real-time stations and legacy stations. It operates by letting one station at a time to disable the back-off algorithm for collision resolution. This privilege is shared among stations by a virtual token rotation mechanism. The implementation of this protocol with reduced processing...
This paper describes the architecture, operation and implementation of the B-Live home automation system. This system has been developed at Micro I/O for assisting elderly and disabled people in their homes. The paper also discusses the demonstrator deployed at the CMRRC Rovisco Pais and proposes an improved information exchange mechanism for the B-Live system.
This paper describes a preliminary work carried on to assess the use of Bluetooth technology to transport MIDI data streams. The proposed approach is based on Bluetooth ACL links. Although the music field motivated the work, the results are significant for the use of Bluetooth ACL links in time critical applications such as industrial automation. In the paper, a test-bed is described and several timing...
This paper describes a preliminary work carried on to assess the use of Bluetooth technology to transport MIDI data streams. The proposed approach is based on the well-known Bluetooth serial port profile. Although the music field motivated the work, the results are significant for the use of the profile in time critical applications such as industrial automation. In the paper a test-bed is described...
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