scholarly journals Efficient Route Management Method for Mobile Nodes in 6TiSCH Network

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3074
Author(s):  
Min-Jae Kim ◽  
Sang-Hwa Chung
Keyword(s):  
High Reliability ◽  
Mobile Node ◽  
Industrial Applications ◽  
Mobile Nodes ◽  
Channel Hopping ◽  
Time Requirements ◽  
Efficient Route ◽  
The Stability ◽  
Exchange Control ◽  
Ieee 802.15

The combination of time slotted access and channel hopping technology in IEEE 802.15 TSCH networks enables high reliability and low power operation to meet the stability and real-time requirements of industrial applications. Basically, TSCH and RPL, a routing protocol for TSCH, are proposed for static nodes that generate fewer control messages, so they allow collisions in shared cells when they exchange control messages. In a topology containing mobile nodes, the collision of control messages in a shared cell makes the network difficult to recover quickly. The proposed scheme minimizes the collision of control messages by allocating dedicated control cells to form preferred parent nodes quickly for mobile nodes. We also proposed a method for establishing a fixed route from the root node to the mobile node in RPL to minimize the delay time. Through the simulation using the 6TiSCH simulator, it was confirmed that the performance of the proposed method was approximately 2.5 times better in terms of overhead and resource use, and 33% better in terms of network participation time of mobile nodes compared with existing solutions.

scholarly journals Collision-Free Advertisement Scheduling for IEEE 802.15.4-TSCH Networks

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1789 ◽  
Author(s):  
Apostolos Karalis ◽  
Dimitrios Zorbas ◽  
Christos Douligeris
Keyword(s):  
Power Consumption ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
High Reliability ◽  
Mobile Nodes ◽  
Medium Access ◽  
Worst Case ◽  
Channel Hopping ◽  
Transmission Schedule ◽  
Scheduling Method

IEEE802.15.4-time slotted channel hopping (TSCH) is a medium access control (MAC) protocol designed to support wireless device networking, offering high reliability and low power consumption, two features that are desirable in the industrial internet of things (IIoT). The formation of an IEEE802.15.4-TSCH network relies on the periodic transmissions of network advertising frames called enhanced beacons (EB). The scheduling of EB transmissions plays a crucial role both in the joining time and in the power consumption of the nodes. The existence of collisions between EB is an important factor that negatively affects the performance. In the worst case, all the neighboring EB transmissions of a node may collide, a phenomenon which we call a full collision. Most of the EB scheduling methods that have been proposed in the literature are fully or partially based on randomness in order to create the EB transmission schedule. In this paper, we initially show that the randomness can lead to a considerable probability of collisions, and, especially, of full collisions. Subsequently, we propose a novel autonomous EB scheduling method that eliminates collisions using a simple technique that does not increase the power consumption. To the best of our knowledge, our proposed method is the first non-centralized EB scheduling method that fully eliminates collisions, and this is guaranteed even if there are mobile nodes. To evaluate our method, we compare our proposal with recent and state-of-the-art non-centralized network-advertisement scheduling methods. Our evaluation does not consider only fixed topology networks, but also networks with mobile nodes, a scenario which has not been examined before. The results of our simulations demonstrate the superiority of our method in terms of joining time and energy consumption.

scholarly journals Transmission Scheduling of Periodic Real-Time Traffic in IEEE 802.15.4e TSCH-Based Industrial Mesh Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Shi ◽  
Lin Zhang ◽  
Zhiying Qi ◽  
Kang Tong ◽  
Hongsheng Chen
Keyword(s):  
Real Time ◽  
Mesh Networks ◽  
High Reliability ◽  
Industrial Applications ◽  
Maximum Matching ◽  
Mesh Topology ◽  
Dynamic Priority ◽  
Real Time Traffic ◽  
Channel Hopping ◽  
Ieee 802.15.4E

Time-slotted channel hopping (TSCH) is a part of an emerging IEEE 802.15.4e standard to enable deterministic low-power mesh networking, which offers high reliability and low latency for wireless industrial applications. Nonetheless, the standard only provides a framework, but it does not mandate a specific scheduling mechanism for time and frequency slot allocation. This paper focuses on a centralized scheme to schedule multiple concurrent periodic real-time flows in TSCH networks with mesh topology. In our scheme, each flow is assigned a dynamic priority based on its deadline and the hops remaining to reach the destination. A maximum matching algorithm is utilized to find conflict-free links, which provides more chances to transfer high-priority flows at each time slot. Frequency allocation is implemented by graph coloring to make finally selected links interference free. Simulation results show that our algorithm clearly outperforms the existing algorithms on the deadline satisfaction ratio with a similar radio duty cycle.

scholarly journals Cooperative Cloud Service Aware Mobile Internet Coverage Connectivity Guarantee Protocol Based on Sensor Opportunistic Coverage Mechanism

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Qin Qin ◽  
Yong-qiang He ◽  
Li-ming Nie
Keyword(s):  
Service Management ◽  
High Reliability ◽  
Cloud Service ◽  
Mobile Node ◽  
Mobile Internet ◽  
Sensor Nodes ◽  
The Internet ◽  
Coverage Ratio ◽  
Application Service ◽  
The Stability

In order to improve the Internet coverage ratio and provide connectivity guarantee, based on sensor opportunistic coverage mechanism and cooperative cloud service, we proposed the coverage connectivity guarantee protocol for mobile Internet. In this scheme, based on the opportunistic covering rules, the network coverage algorithm of high reliability and real-time security was achieved by using the opportunity of sensor nodes and the Internet mobile node. Then, the cloud service business support platform is created based on the Internet application service management capabilities and wireless sensor network communication service capabilities, which is the architecture of the cloud support layer. The cooperative cloud service aware model was proposed. Finally, we proposed the mobile Internet coverage connectivity guarantee protocol. The results of experiments demonstrate that the proposed algorithm has excellent performance, in terms of the security of the Internet and the stability, as well as coverage connectivity ability.

scholarly journals Downward traffic retransmission mechanism for improving reliability in RPL environment supporting mobility

2020 ◽  
Vol 16 (1) ◽  
pp. 155014772090360
Author(s):  
Soon-Woong Min ◽  
Sang-Hwa Chung ◽  
Hee-Jun Lee ◽  
Yu-Vin Ha
Keyword(s):  
Low Power ◽  
Routing Protocol ◽  
Task Force ◽  
Mobile Node ◽  
Mobile Nodes ◽  
Lossy Networks ◽  
Industrial Internet ◽  
Channel Hopping ◽  
Lower Transmission ◽  
Retransmission Mechanism

With the diversification of industrial Internet of Things applications, there is a growing demand for mobility support in industrial wireless networking environments. However, the routing protocol for low-power and lossy networks is designed based on a static environment and is vulnerable in a mobility environment. Routing protocol for low-power and lossy networks is an Internet engineering task force standard in the low-power and lossy network environments used mainly in industrial environments. In addition, although routing protocol for low-power and lossy networks is based on collection tree protocol and is suitable for data collection and upward traffic transmission, it struggles with downward traffic transmission in terms of control, actuation, and end-to-end transmission. In this article, the problems caused by mobile nodes in routing protocol for low-power and lossy networks are discussed, and a retransmission scheme named IM-RPL is proposed. This retransmission scheme can improve the performance of downward traffic for the mobile nodes by retransmitting the packets to the neighbor nodes, the mobile node’s new parent sets, and relaying them to the mobile node. Its performance is evaluated through an experiment. The results demonstrate that using OpenMote in OpenWSN’s time slotted channel hopping induces a packet reception ratio improvement and a lower transmission delay as compared to standard routing protocol for low power and lossy.

scholarly journals Suboptimal Disturbance Observer Design Using All Stabilizing Q Filter for Precise Tracking Control

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1434 ◽  
Author(s):  
Wonhee Kim ◽  
Sangmin Suh
Keyword(s):  
Design Method ◽  
Industrial Applications ◽  
Point Of View ◽  
Observer Design ◽  
Linear Matrix ◽  
External Disturbances ◽  
Closed Loop Systems ◽  
Control Target ◽  
The Stability ◽  
Unified Index

For several decades, disturbance observers (DOs) have been widely utilized to enhance tracking performance by reducing external disturbances in different industrial applications. However, although a DO is a verified control structure, a conventional DO does not guarantee stability. This paper proposes a stability-guaranteed design method, while maintaining the DO structure. The proposed design method uses a linear matrix inequality (LMI)-based H∞ control because the LMI-based control guarantees the stability of closed loop systems. However, applying the DO design to the LMI framework is not trivial because there are two control targets, whereas the standard LMI stabilizes a single control target. In this study, the problem is first resolved by building a single fictitious model because the two models are serial and can be considered as a single model from the Q-filter point of view. Using the proposed design framework, all-stabilizing Q filters are calculated. In addition, for the stability and robustness of the DO, two metrics are proposed to quantify the stability and robustness and combined into a single unified index to satisfy both metrics. Based on an application example, it is verified that the proposed method is effective, with a performance improvement of 10.8%.

A DENSITY FUNCTIONAL STUDY OF THE STRUCTURE OF SILANE COUPLING AGENT 3–AMINOPROPYLTRIETHOXYSILANE

2005 ◽  
Vol 04 (01) ◽  
pp. 117-126
Author(s):  
N. L. MA ◽  
P. WU
Keyword(s):  
Coupling Agent ◽  
Density Functional ◽  
Solution Structure ◽  
Silane Coupling Agent ◽  
Industrial Applications ◽  
Functional Study ◽  
Stable Form ◽  
Functional Theory ◽  
Silane Coupling ◽  
The Stability

Using density functional theory, we predicted the solution structure of the hydrolyzed 3–aminopropyltriethoxysilane (h–APS), which is a silane coupling agent commonly used in many industrial applications. We have located five stable minima on the potential energy surface of h–APS in which four of them are "neutral", and the remaining one is zwitterionic (dipolar) in nature. Our calculations suggested that the stability of the most stable form of h–APS in water (denoted as II_N) arose from strong intramolecular OH ⋯ N hydrogen bond. The least stable form is the zwitterionic form (I_ZW), which is estimated to be over 90 kJ mol -1 less stable than II_N. The factors governing the relative stabilities of different forms are discussed.

scholarly journals A TOTP-Based Enhanced Route Optimization Procedure for Mobile IPv6 to Reduce Handover Delay and Signalling Overhead

2014 ◽  
Vol 2014 ◽  
pp. 1-16
Author(s):  
Peer Azmat Shah ◽  
Halabi B. Hasbullah ◽  
Ibrahim A. Lawal ◽  
Abubakar Aminu Mu’azu ◽  
Low Tang Jung
Keyword(s):  
Mobile Devices ◽  
Optimization Procedure ◽  
Mobile Node ◽  
Mobile Ipv6 ◽  
Route Optimization ◽  
Network Simulator ◽  
Mobile Nodes ◽  
Home Test ◽  
One Time Password ◽  
Signalling Overhead

Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node’s reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node’s compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6’s Return-Routability-based Route Optimization (RR-RO).

Chaos control of permanent magnet synchronous motor using simple controllers

2018 ◽  
Vol 41 (8) ◽  
pp. 2352-2364 ◽  
Author(s):  
Arif Iqbal ◽  
Girish Kumar Singh
Keyword(s):  
Permanent Magnet ◽  
Chaos Control ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Industrial Applications ◽  
Stable Operation ◽  
Comparative Performance ◽  
Experimental Implementation ◽  
Chaotic Characteristic ◽  
The Stability

Owing to the superior properties and stable operation, the Permanent Magnet Synchronous Motor (PMSM) is preferably used in wide industrial applications. But, the stability of motor is found to be dependent on its initial operating condition, showing the chaotic characteristic. Therefore, this paper addresses the chaos control of PMSM by developing four simple but effective controllers, which are mathematically designed by using the principle of Lyapunov’s method for asymptotic global stability. A comparative performance assessment has been carried out for the developed controllers in terms of settling time and peak over shoot. Furthermore, the concept of conventional proportional-integration type controller has been extended to develop two more controllers for chaos control of PMSM. Numerical simulation has been carried out in Matlab environment for performance evaluation of developed controllers. The obtained analytical results have been validated through experimental implementation in real time environment on Multisim/Ultiboard platform.

scholarly journals Immobilization of Mutant Phosphotriesterase on Fuller’s Earth Enhanced the Stability of the Enzyme

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 983
Author(s):  
Wahhida Latip ◽  
Victor Feizal Knight ◽  
Ong Keat Khim ◽  
Noor Azilah Mohd Kasim ◽  
Wan Md Zin Wan Yunus ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Metal Ions ◽  
Half Life ◽  
Industrial Applications ◽  
Free Enzyme ◽  
High Tolerance ◽  
Tween 40 ◽  
Fuller’S Earth ◽  
The Stability ◽  
Biochemical Features

Immobilization is a method for making an enzyme more robust in the environment, especially in terms of its stability and reusability. A mutant phosphotriesterase (YT PTE) isolated from Pseudomonas dimunita has been reported to have high proficiency in hydrolyzing the Sp and Rp-enantiomers of organophosphate chromophoric analogs and therefore has great potential as a decontamination agent and biosensor. This work aims to investigate the feasibility of using Fuller’s earth (FE) as a YT PTE immobilization support and characterize its biochemical features after immobilization. The immobilized YT PTE was found to show improvement in thermal stability with a half-life of 24 h compared to that of the free enzyme, which was only 8 h. The stability of the immobilized YT PTE allowed storage for up to 4 months and reuse for up to 6 times. The immobilized YT PTE showed high tolerance against all tested metal ions, Tween 40 and 80 surfactants and inorganic solvents. These findings showed that the immobilized YT PTE became more robust for use especially with regards to its stability and reusability. These features would enhance the future applicability of this enzyme as a decontamination agent and its use in other suitable industrial applications.

scholarly journals Dispersion stability and rheological characteristics of water and ethylene glycol based zinc oxide nanofluids

2020 ◽  
pp. 187-187
Author(s):  
Adnan Qamar ◽  
Attique Arshad ◽  
Zahid Anwar ◽  
Rabia Shaukat ◽  
Muhammad Amjad ◽  
...  
Keyword(s):  
Experimental Data ◽  
Ethylene Glycol ◽  
Industrial Applications ◽  
Deionized Water ◽  
Rheological Characteristics ◽  
Particle Loading ◽  
Viscosity Models ◽  
Vis Spectroscopy ◽  
Settling Speed ◽  
The Stability

With advancement of nanoscience, ?nanofluids? are becoming quite popular among thermal engineers. High thermal conductivity, relatively less settling speed, and higher surface area of nanoparticles are a few key promoting properties. The last two decades have seen dramatic progress towards using nanoparticles in industrial applications. However, the stability and rheological characteristics of prepared nanofluids have serious effects on their transport characteristics, but unfortunately, this has not found proper attention from researchers. In this study, stability and rheological characteristics of ZnO nanoparticles within deionized water, ethylene glycol, and their blends have been extensively tested. Stability was observed using UV-vis spectroscopy, while the viscosity was measured with the help of a rheometer. The data was collected with 0.011-0.044 wt. % loading of nanoparticles, while experiments were conducted within 15-55oC temperature range. Better stability was recorded when nanofluids were prepared with pure ethylene glycol. Experiments showed that the viscosity increased with particle loading, whereas the effect of surfactants appeared to be insignificant. Research results were used to assess predictions of different viscosity models. Experimental data was overpredicted by Einstein, Brinkman, and Batchelor?s models.

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