F-LEACH: a fuzzy-based data aggregation scheme for healthcare IoT systems

The Journal of Supercomputing - Internet of Things (IoT) is an emerging paradigm that consists of numerous connected and interrelated devices with embedded sensors, exchanging data with each other...     

GAPSO-SVM: An IDSS-based Energy-Aware Clustering Routing Algorithm for IoT Perception Layer

Wireless Personal Communications - With the emergence of Internet of Things (IoT) having large scale and generating huge amount of data, Intelligent Decision Support Systems (IDSSs) have attracted...     

A Simple and Closed-Form Access Delay Model for Reliable IEEE 802.11-Based Wireless Industrial Networks

With the ongoing popularity of the IEEE 802.11 standard, many analytical studies for the distributed coordination function (DCF) have been reported but due to lack of a comprehensive model, the research has been going on. In this paper, three probabilistic analytical access delay models have been proposed for the IEEE 802.11 DCF mechanism in saturated traffic and noisy industrial applications. The first and second one provide an accurate packet delay model by solving non-linear equations at low and high Signal to Noise Ratios (SNRs) respectively. The third one on the other hand offers an approximate and simple closed-form model which does not need solving any non-linear equation and therefore can easily be utilized in the distributed adaptive network quality of service provisioning algorithms for industrial nodes which usually have limited processing capabilities. Delay-reliability, delay-packet payload and delay-data rate tradeoffs has also been studied. Simulation results match the theoretical derivations in most SNRs, confirming the effectiveness of the proposed models.     

A Simple and Comprehensive Saturation Packet Delay Model for Wireless Industrial Networks

With the emerging popularity of the wireless local area network technology, many analytical models for its main medium access control mechanism, Distributed Coordination Function (DCF), have been reported. However, most of them are based on some oversimplifying assumptions, or need very complicated mathematical manipulations. In this paper, a simple and accurate packet delay model has been proposed for the IEEE 802.11 DCF mechanism in saturated traffic and error-prone industrial applications which is based on a modified discrete-time Markov chain model of the DCF mechanism which accounts for the backoff freezing. It estimates various delay parameters including the average, jitter, Cumulative Distribution Function, and the effect of Retry Limit. The simulation results confirm the accuracy of the proposed delay model compared with other similar models in the literature.     

Reanalyzing a simplified Markov model for the low-density P2P wireless sensor and actuator networks

Telecommunication Systems - Wireless sensor and actuator networks (WSAN) are an important part of the emerging Industrial Internet of Things concept. Providing a computationally simple but...     

Adaptive Fuzzy Sliding Mode Control of Under-actuated Nonlinear Systems

A new extension of the conventional adaptive fuzzy sliding mode control (AFSMC) scheme, for the case of under-actuated and uncertain affine multiple-input multiple-output (MIMO) systems, is presented. In particular, the assumption for non-zero diagonal entries of the input gain matrix of the plant is relaxed. In other words, the control effect of one actuator can propagate from a subgroup of canonical state equations to the rest of equations in an indirect sense. The asymptotic stability of the proposed AFSM control method is proved using a Lyapunov-based methodology. The effectiveness of the proposed method for the case of under-actuated systems is investigated in the presence of plant uncertainties and disturbances, through simulation studies.     

A comprehensive DCF performance analysis in noisy industrial wireless networks

The use of wireless technology in industrial networks is becoming more popular because of its flexibility, reduction of cable cost, and deployment time. Providing an accurate model to study the most important parameters of these networks, the timeliness and reliability, is essential in assessing the network metrics and choosing proper protocol settings. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 is a common and established wireless technology, and several analytical models have been proposed to assess its performance; however, most of them are accurate only for a limited network situation, especially data networks that have large packet payloads and are used at high signal to noise ratios, and cannot be applied to study the performance of industrial networks that have short packet lengths and are used in harsh and noisy environments. In this paper, a novel three‐dimensional discrete‐time Markov chain model has been proposed for the IEEE 802.11‐based industrial wireless networks using the distributed coordination function as the medium access control mechanism in the worst‐case saturated traffic. It considers both causes of the backoff freezing: busy channel and the successive interframe space waiting time. In this way, it provides a much more accurate estimation of the channel access and error probabilities, resulting in a more accurate network parameter calculation. Also, based on the proposed model, a comprehensive packet delay analysis, including average, jitter, and cumulative distribution function, has been provided for the near 100% reliable industrial scenario and error‐prone channel condition, which in comparison with similar pieces of work provides much more accurate results. Copyright © 2014 John Wiley & Sons, Ltd.