scholarly journals Characterization, Statistical Analysis and Method Selection in the Two-Clocks Synchronization Problem for Pairwise Interconnected Sensors

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4808
Author(s):  
Juan-Antonio Fernández-Madrigal ◽  
Angeles Navarro ◽  
Rafael Asenjo ◽  
Ana Cruz-Martín
Keyword(s):  
Time Synchronization ◽  
Clock Synchronization ◽  
Selection Procedure ◽  
Time Estimation ◽  
Computational Effort ◽  
Common Time ◽  
Synchronization Problem ◽  
Method Selection ◽  
Super Computer ◽  
Application Requirements

Time synchronization among sensor devices connected through non-deterministic media is a fundamental requirement for sensor fusion and other distributed tasks that need a common time reference. In many of the time synchronization methods existing in literature, the estimation of the relation between pairs of clocks is a core concept; moreover, in applications that do not have general connectivity among its devices but a simple pairwise topology, such as embedded systems, mobile robots or home automation, two-clock synchronization is actually the basic form of the time estimation problem. In these kinds of applications, especially for critical ones, not only the quality of the estimation of the relation between two clocks is important, but also the bounds the methods provide for the estimated values, and their computational effort (since many are small systems). In this paper, we characterize, with a thorough parameterization, the possible scenarios where two-clock synchronization is to be solved, and then conduct a rigorous statistical study of both scenarios and methods. The study is based on exhaustive simulations run in a super-computer. Our aim is to provide a sound basis to select the best clock synchronization algorithm depending on the application requirements and characteristics, and also to deduce which ones of these characteristics are most relevant, in general, when solving the problem. For our comparisons we have considered several representative methods for clock synchronization according to a novel taxonomy that we also propose in the paper, and in particular, a few geometrical ones that have special desirable characteristics for the two-clock problem. We illustrate the method selection procedure with practical use-cases of sensory systems where two-clock synchronization is essential.

Performance Evaluation of Time Synchronized Multi Layer-MAC Protocol

2019 ◽  
Vol 13 (3) ◽  
pp. 249-255
Author(s):  
Manju Khurana ◽  
Manish Kumar Jha
Keyword(s):  
Network Lifetime ◽  
Time Synchronization ◽  
Mac Protocol ◽  
Wireless Sensor ◽  
Time Intervals ◽  
Common Time ◽  
Packet Retransmission ◽  
Simulation Results ◽  
Application Requirements ◽  
Throughput And Delay

Background & Objective: Patents suggest that time synchronization in Wireless Sensor Network (WSN) directs at imparting a common time scale for local clocks of nodes in the network. It has been observed that all hardware clocks are unsynchronized, local clocks of nodes may drift away from each other in time. Hence durations of time intervals may differ for each node in the network. This paper evaluates the performance by suggesting an algorithm for time synchronized MLMAC protocol. Methods: Packet retransmission drains the non-replaceable power source that degrades the network lifetime, one of the major concerns in WSN. Simulation results indicate that time synchronized MLMAC outperforms the existing ML-MAC scheme in terms of both energy efficiency and packets dropped at individual nodes. Results: After Analyzing the results of simulation, network for improved synchronization performs better w.r.t. network lifetime and packets dropped. Throughput and delay are matter of concern which needs to be explored further. Conclusion: Simulation results validate the proposed protocol under various network conditions and application requirements.

scholarly journals Clocks, power and synchronization in duty-cycled wireless sensor nodes

2011 ◽  
Vol 24 (2) ◽  
pp. 183-208 ◽  
Author(s):  
Mile Stojcev ◽  
Ljubisa Golubovic ◽  
Tatjana Nikolic
Keyword(s):  
Time Scale ◽  
Large Scale ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Low Cost ◽  
Limited Resource ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Reference Source ◽  
Common Time

Recent advances in CMOS VLSI ICs and micro-electromechanical technology have led to development of small, low-cost, and low-power multifunctional sensors. Wireless sensor networks (WSNs) are large-scale networks of such sensors, dedicated to observing and monitoring various aspects of the physical world. Some intrinsic properties of WSNs including limited resource of energy, storage, computation, and bandwidth, make traditional synchronization methods unsuitable for WSNs. Time synchronization as an important issue consists of giving all sensor nodes (SNs) of the WSN a common time scale to operate. The common time scale is usually achieved by periodically synchronizing the clock of each SN to a reference source. In this manner the local time seen by each SN of the network is approximately the same, and time synchronization allows the entire system to cooperate. This paper gives a brief look to the time synchronization problem and the need for synchronization in WSNs. Then it points out that clock systems become a bottle-neck, after that it presents the available current clock technologies, next it examines the influence of these clock technologies, and finally provides guidelines for WSN developers who must choose among the different clock synchronization techniques.

Time Synchronization in Tandem Hot Strip Line Based on Improved Broadcast Mode

2013 ◽  
Vol 341-342 ◽  
pp. 679-683
Author(s):  
Jian Zhao Cao ◽  
Dian Hua Zhang
Keyword(s):  
Control System ◽  
Process Control ◽  
Time Synchronization ◽  
Process Control System ◽  
New Method ◽  
Strip Line ◽  
Total Delay ◽  
Synchronization Problem ◽  
Hot Strip ◽  
Distributed Process

In order to solve the time synchronization problem in tandem hot strip line, the traditional algorithm of time synchronization was analyzed, and the server-client mode was compared with the broadcast mode using multithread technology, then the present paper improved the broadcast mode to improve its precision. The new method can estimate total delay including clock offset and network transmission time. A simple, easy and little loading time synchronization method was designed for the distributed process control system of tandem hot strip line. The new method was applied in domestic some tandem hot strip line successfully which showed that it could meet the demands of process control system with little expenses, simple structure and high precision.

scholarly journals An Efficient Algorithm for Partial Discharge Localization in High-Voltage Systems Using Received Signal Strength

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4000 ◽  
Author(s):  
Umar F. Khan ◽  
Pavlos I. Lazaridis ◽  
Hamd Mohamed ◽  
Ricardo Albarracín ◽  
Zaharias D. Zaharis ◽  
...  
Keyword(s):  
High Voltage ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Human Life ◽  
Partial Discharge ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Time Of Arrival ◽  
Localization Algorithm ◽  
Require Time

The term partial discharge (PD) refers to a partial bridging of insulating material between electrodes that sustain an electric field in high-voltage (HV) systems. Long-term PD activity can lead to catastrophic failures of HV systems resulting in economic, energy and even human life losses. Such failures and losses can be avoided by continuously monitoring PD activity. Existing techniques used for PD localization including time of arrival (TOA) and time difference of arrival (TDOA), are complicated and expensive because they require time synchronization. In this paper, a novel received signal strength (RSS) based localization algorithm is proposed. The reason that RSS is favoured in this research is that it does not require clock synchronization and it only requires the energy of the received signal rather than the PD pulse itself. A comparison was made between RSS based algorithms including a proposed algorithm, the ratio and search and the least squares algorithm to locate a PD source for nine different positions. The performance of the algorithms was evaluated by using two field scenarios based on seven and eight receiving nodes, respectively. The mean localization error calculated for two-field-trial scenarios show, respectively, 1.80 m and 1.76 m for the proposed algorithm for all nine positions, which is the lowest of the three algorithms.

The Hardware Design of Measurement System of Transmission Lines Based on Wireless Communication

2015 ◽  
Vol 1092-1093 ◽  
pp. 366-369
Author(s):  
Shu Min Sun ◽  
Wen Juan Jiang ◽  
Yu Meng ◽  
Yan Cheng
Keyword(s):  
Wireless Communication ◽  
Data Storage ◽  
Measurement System ◽  
Transmission Lines ◽  
High Speed ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Report Generation ◽  
Test Efficiency ◽  
Synchronization Module

A set of measurement system for the testing of transmission lines, composing of wireless center station, wireless current acquisition and transmission nodes, wireless voltage acquisition and transmission node, was designed, which was based on wireless communication. The high speed wireless bridge working at 2.4GHz together with the clock synchronization module based on the IEEE1588 communicating protocol were both employed for the communication and time synchronization separately. The measurement system has data storage, waveform display, data analysis, automatic report generation and other functions. The measurement system can greatly reduced arrangement of cables, thereafter improved the test efficiency.

scholarly journals A Computational Modeling for Knowledge Binding of the Unstructured Web Data

2019 ◽  
Vol 9 (2S) ◽  
pp. 418-424
Keyword(s):  
Theoretical Analysis ◽  
Computational Modeling ◽  
Computational Effort ◽  
Significant Extent ◽  
Web Data ◽  
Web Based ◽  
Matching Algorithm ◽  
Computational Performance ◽  
Application Requirements ◽  
Unstructured Information

The focus of this manuscript is laid towards extracting insightful data embedded into web-based information which is crucial for various academic and commercialized application requirements. The study thereby introduces a robust computational modeling by means of computing knowledge from collaborative web-based unstructured information. For this purpose, this design is simplified with Fuzzy based matching algorithm and also with a set of procedures which reduces the computational effort to a significant extent. The numerical theoretical analysis shows that the effectiveness of the formulated model. It also shows that the formulated concept outperforms the baseline modeling by almost 50% when computational performance is concerned.

Finite-time synchronization for fuzzy inertial cellular neural networks with time-varying delays via integral inequality

2021 ◽  
pp. 1-14
Author(s):  
Zhenjie Wang ◽  
Wenxia Cui ◽  
Wenbin Jin
Keyword(s):  
Neural Networks ◽  
Integral Inequality ◽  
Finite Time ◽  
Time Synchronization ◽  
Cellular Neural Networks ◽  
Time Varying ◽  
Time Stability ◽  
Finite Time Stability ◽  
Synchronization Problem ◽  
Inequality Techniques

This paper mainly considers the finite-time synchronization problem of fuzzy inertial cellular neural networks (FICNNs) with time-varying delays. By constructing the suitable Lyapunov functional, and using integral inequality techniques, several sufficient criteria have been proposed to ensure the finite-time synchronization for the addressed (FICNNs). Without applying the known finite-time stability theorem, which is widely used to solve the finite-time synchronization problems for (FICNNs). In this paper, the proposed method is relatively convenient to solve finite-time synchronization problem of the addressed system, this paper extends the research works on the finite-time synchronization of (FICNNs). Finally, numerical simulations illustrated verify the effectiveness of the proposed results.

scholarly journals Overview of Time Synchronization for IoT Deployments: Clock Discipline Algorithms and Protocols

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5928
Author(s):  
Hüseyin Yiğitler ◽  
Behnam Badihi ◽  
Riku Jäntti
Keyword(s):  
Time Synchronization ◽  
Clock Synchronization ◽  
Constrained Systems ◽  
Clock Model ◽  
Network Time ◽  
Expected Performance ◽  
The Everyday ◽  
Network Time Protocol ◽  
Synchronization Problems ◽  
Constrained Devices

Internet of Things (IoT) is expected to change the everyday life of its users by enabling data exchanges among pervasive things through the Internet. Such a broad aim, however, puts prohibitive constraints on applications demanding time-synchronized operation for the chronological ordering of information or synchronous execution of some tasks, since in general the networks are formed by entities of widely varying resources. On one hand, the existing contemporary solutions for time synchronization, such as Network Time Protocol, do not easily tailor to resource-constrained devices, and on the other, the available solutions for constrained systems do not extend well to heterogeneous deployments. In this article, the time synchronization problems for IoT deployments for applications requiring a coherent notion of time are studied. Detailed derivations of the clock model and various clock relation models are provided. The clock synchronization methods are also presented for different models, and their expected performance are derived and illustrated. A survey of time synchronization protocols is provided to aid the IoT practitioners to select appropriate components for a deployment. The clock discipline algorithms are presented in a tutorial format, while the time synchronization methods are summarized as a survey. Therefore, this paper is a holistic overview of the available time synchronization methods for IoT deployments.

scholarly journals Finite-Time Synchronization for a Class of Multiweighted Complex Networks with Markovian Switching and Time-Varying Delay

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-25
Author(s):  
Ying Liu ◽  
Fei Chen ◽  
Bin Yang ◽  
Xin Wang ◽  
Weiming Wang
Keyword(s):  
Complex Networks ◽  
Finite Time ◽  
Time Synchronization ◽  
Time Estimation ◽  
Markovian Switching ◽  
Convergence Time ◽  
Time Varying ◽  
Time Varying Delay ◽  
The Impact ◽  
Varying Delay

In this paper, we investigate the finite-time synchronization control for a class of nonlinear coupled multiweighted complex networks (NCMWCNs) with Markovian switching and time-varying delay analytically and quantitatively. The value of this study lies in four aspects: First, it designs the finite-time synchronization controller to make the NCMWCNs with Markovian switching and time-varying delay achieve global synchronization in finite time. Second, it derives two kinds of finite-time estimation approaches by analyzing the impact of the nonlinearity of nonlinear coupled function on synchronization dynamics and synchronization convergence time. Third, it presents the relationship between Markovian switching parameters and synchronization problems of subsystems and the overall system. Fourth, it provides some numerical examples to demonstrate the effectiveness of the theoretical results.

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