Scheduling Protocol Research Articles

Integral Input-to-State Stability of Networked Control Systems

We investigate integral input-to-state stability (iISS) of nonlinear networked control systems (NCSs). The controller is designed by emulation, i.e., it is constructed to ensure iISS for the closed-loop system in the absence of the network. Afterward, the latter is taken into account and explicit conditions are provided on the scheduling protocol and the maximum allowable transmission interval to preserve iISS for the NCS. The results are applied to two case studies: bilinear systems and neutrally stable linear systems under saturated feedback, where the conditions are formulated as linear matrix inequalities. The effectiveness of the results is further illustrated via a numerical example.

Energy-Efficient Protocol of Link Scheduling in Cognitive Radio Body Area Networks for Medical and Healthcare Applications.

Wireless body area networks (WBANs) have become a new paradigm for electronic healthcare applications; for instance, they are used to efficiently monitor patients in real-time. In this paper, an energy-efficient link scheduling (ELS) protocol for cognitive radio body area networks (CRBANs) is proposed, which aims to minimize energy consumption in CRBANs, while achieving higher probabilities of successful transmissions with multiple CRBANs. The proposed ELS transmits packets in the common control channel to control transmission links amongst CRBANs to the gateway and vice versa. The transmissions of CRBANs to the gateway are scheduled at a specific time by the gateway in different data channels, according to the traffic priority of CRBANs. Packet delivery ratio, delay, and energy consumption are evaluated for multiple CRBANs via extensive simulation.

EA-MAC: A QoS Aware Emergency Adaptive MAC Protocol for Intelligent Scheduling of Packets in Smart Emergency Monitoring Applications

The evolution of the wireless sensor network (WSN) in recent years has reached its greatest heights and applications are increasing day by day, one such application is Smart Emergency Monitoring Systems (SMESs) which is in vision of implementation in every urban and rural areas. The implementation of WSN architecture in the Smart Monitoring Systems needs an intelligent scheduling mechanism that efficiently handles the high traffic load as well as the emergency traffic load without sacrificing the energy efficiency of the network. However, the traditional scheduling algorithms such as First Come First Served (FCFS), Round Robin, and Shortest Job First (SJF) cannot meet the requirements of high traffic load in SMESs. To address these shortcomings, this paper presents Emergency Adaptive Medium Access Control protocol (EA-MAC), a fuzzy priority scheduling based Quality-of-service (QoS)-aware medium access control (MAC) protocol for hierarchical WSNs. EA-MAC protocol employs the most powerful fuzzy logics to schedule the sensor nodes with both normal and emergency traffic load without any data congestion, and packet loss and maintaining the better QoS which is considered to be more important in SMESs applications. Moreover, a novel rank-based clustering mechanism in EA-MAC protocol prolongs the network lifetime by minimizing the distance between the Cluster Head (CH) and the Base Station (BS). Both analytical and simulation models demonstrate the superiority of the EA-MAC protocol in terms of energy consumption, transmission delay and data throughput when compared with the existing Time Division Multiple Access (TDMA) based MAC protocols such as LEACH protocol and Cluster Head Election Mechanism-Based On Fuzzy Logic (CHEF) protocol.

Security Sliding Mode Control of Interval Type-2 Fuzzy Systems Subject to Cyber Attacks: The Stochastic Communication Protocol Case

This article addresses the security control problem of a class of interval type-2 fuzzy systems via the sliding mode control strategy. A stochastic communication scheduling protocol is utilized to govern the transmission from the sensors to the controller, by which only one sensor node has the chance to transmit its value at every instant. Meanwhile, cyber attacks from malicious adversaries might be launched in vulnerable communication channels. To quantitatively analyze the effect of the stochastic communication protocol and cyber attacks, their mathematical model is first constructed based on a compensation scheme. Since the scheduling signal may be unavailable once cyber attacks are activated, a desirable sliding mode control law is synthesized with token-independent control gains, whose membership functions are mismatched with those of the fuzzy system. To deal with these mismatched membership functions, the relations between the membership functions of the system and the control law are reconstructed. Consequently, the favorable property of perfectly matched memberships could be employed. Sufficient conditions are derived so that the resultant closed-loop interval type-2 fuzzy system is stochastically stable and, at the same time, the state trajectories can be forced into a small domain around the prescribed sliding surface. The proposed control design approach is verified by two examples.

A Cross Layer Design and Flower Pollination Optimization Algorithm for Secured Energy Efficient Framework in Wireless Sensor Network

One of the fast-growing, tremendous and highly demanding networks from various emerging applications like military, healthcare industry, airport and forests is wireless sensor network. These applications are incorporated into the cloud in order to utilize various energy resources, high performance computing and massive storage structure. Many challenges should be resolved in sensor cloud environment like security, continuous data transmission, power management and energy efficiency. Some of the earlier research works anticipated data compression method for energy conservation and encryption decryption algorithms for secured data transmission. Compressing different data from various sources is difficult which degrades the performance of the data transmission and encryption decryption has taken more computational time and complexity which raises the need for energy efficiently and secured data transmission schemes. Hence, this paper is motivated to solve the major issues in sensor cloud, energy efficiency, data security and maintenance and thereby improving the quality of service (QoS). A secured energy efficient framework (SEEF) is designed for secured data transmission and maintenance which comprises of various phases like a cross layer designed for power and traffic management, node and route investigation for security and dynamic optimal routing for improving the QoS using flower pollination algorithm. A smart duty cycle scheduling protocol (SDCS) is proposed to increase the lifetime of the network by avoiding data redundancy, transmission conflicts, traffic conflicts and energy reduction in the network. The end to end delay is reduced by reducing the interval between the packets and packet delivery ratio is improved by avoiding packet loss. SEEF is simulated in NS2 simulator and the results are verified. The performance shows that the throughput and packet delivery ratio is improved up to 0.57 MB/s and 96% respectively. The end to end delay and the energy consumed is reduced to 0.69 s and 0.076 J respectively. From the comparison it is identified that SEEF can increase the overall performance in sensor cloud.

Decentralized Dynamic Event-Triggered $\mathcal {H}_{\infty }$ Control for Nonlinear Systems With Unreliable Communication Channel and Limited Bandwidth

This article investigates the dynamic event-triggered $\mathcal {H}_{\infty }$ control problem for nonlinear networked control systems with unreliable communication channel, variable communication delays, and limited bandwidth. The nonlinear plant is represented by discrete-time polynomial fuzzy model. First, a decentralized dynamic event-triggered mechanism is proposed to determine whether the measured data are transmitted or not, and in order to exclude data collision caused by limited bandwidth, novel try-once-discard and flexible round-robin scheduling protocols are proposed to assign communication channel to certain sensor node. Then, Bernoulli distribution is employed to model the unreliable communication channel, and a new random sequence is developed to model the received data sequence under the effect of data losses and scheduling protocols. Furthermore, a discrete-time stochastic system model with both state and error delays is constructed, and sufficient conditions in the form of sum-of-squares are developed for the design of $\mathcal {H}_{\infty }$ controllers such that the closed-loop system is stochastically stable and preserves guaranteed $\mathcal {H}_{\infty }$ performance. Finally, two simulation examples are provided to illustrate the effectiveness of the proposed results.

TDMA Scheduling in Spatially Extended LiFi Networks

Optical Wireless Communication (OWC) has attracted significant attention from academia and industry as a promising solution to complement traditional radio frequency communication. In Light-Fidelity (LiFi) networks, to enable soft handover and provide robustness against blockage of the line-of-sight links, LiFi receivers are designed to see multiple LiFi transmitters within their field-of-view. To trade-off spatial multiplexing with harmful interference, a proper user scheduling technique is required. In this work, we first derive practical and exact expressions for determining which simultaneous transmissions will create harmful interference and should be scheduled in multiple time-slots. Afterwards, relying on this expression, we propose our semi-distributed Spatially Extended TDMA algorithm, which is based on a time division contention–free access scheme. In contrast to more complex algorithms in the state-of-the-art, our scheduling protocol can reduce the computation time while also achieving a superior minimal user throughput. For a scenario with 9 transmitters and up to 15 receivers, our protocol is at least a factor 120 faster and can improve the minimal user throughput up to 91%, making it suitable for practical roll-out as a promising solution for very dense LiFi networks.

Impact of interference free frequency channels on optimum time slot allocation for priority-based TSCH MAC

Time slotted channel hopping (TSCH), the most promising MAC protocol under IEEE 802.15.4 is meeting the growing demands of low power and determinism in time critical industrial wireless applications. An efficient duty cycle is a necessary mandate for time critical applications which can be achieved by an appropriate reduction of active time slots in the slot frame and this saves node power. Even though many attempts were done in realising an optimum scheduling protocol, the impact of the number of channels on the optimum time slot allocation is not yet considered which signifies importance with the present scenario of many channels being induced by interference from neighbouring wireless networks. Optimum time slot is essential for making efficient duty cycle. Hence, a study on the impact of the number of channels on the optimum time slot allocation is necessitated and is accomplished in this paper. It is found that increasing the number of channels beyond a certain value does not have an impact on the optimum slot allocation and there is a direct relationship between the number of channels and the number of links per track and number of root node branches.

Efficacy and safety of glecaprevir and pibrentasvir combination therapy in old-aged patients with chronic hepatitis C virus infection.

Objective: Combination therapy with glecaprevir and pibrentasvir (G/P) has been shown to provide a sustained virologic response (SVR) rate of >97% in patients with chronic hepatitis C virus (HCV) infection in the first published real-world Japanese data. However, a recently published study showed that the treatment was often discontinued in patients ≥75 years old, resulting in low SVR in intention-to-treat (ITT) analysis. Thus, our aim was to evaluate real-world data for G/P therapy in patients ≥75 years of age, the population density of which is high in “rural” regions.Patients and Methods: We conducted a multicenter study to assess the efficacy and safety of G/P therapy for chronic HCV infection, in the North Kanto area in Japan.Results: Of the 308 patients enrolled, 294 (95.5%) completed the treatment according to the protocol. In ITT and per-protocol analyses, the overall SVR12 rate was 97.1% and 99.7%, respectively. The old-aged patients group consisted of 59 participants, 56 of whom (94.9%) completed the scheduled protocol. Although old-aged patients tended to have non-SVR factors such as liver cirrhosis, history of HCC, and prior DAA therapies, the SVR12 rates in old-aged patients were 98.3% and 100% in the ITT and PP analyses, respectively. Of 308 patients enrolled, adverse events were observed in 74 patients (24.0%), with grade ≥3 events in 8 patients (2.6%). There was no significant difference in any grade and grade ≥3 adverse events between the old-aged group and the rest of the study participants. Only one patient discontinued the treatment because of adverse events.Conclusion: G/P therapy is effective and safe for old-aged patients.

Dynamic Network Access Scheduling and Stabilization of TPCS Networked Control System

The Networked Control Systems (NCS) is a significant arena in the current complex technical scenario. NCS provides the user a wide range of scope in mitigation of its underlying issues in order to benefit the versatility of the network. Two Inverted Pendulums Coupled by a Spring (TPCS) system is one of the finest platforms to study NCS and its issues. The objective considered here is to stabilize both the pendulums at desired vertical position while the “Medium Access Constraint” of NCS is addressed. The proposed Dynamic Medium Access Scheduling strategy aims at analyzing the issue so that it can be applied in practical scenarios. In this paper (i) TPCS is modelled as a switched system (ii) Dynamic Medium Access Scheduling protocols are discussed, selected and applied to TPCS and (iii) the best of the two: Weighted Fastest Decay and Guaranteed Dwell-Time methods to give a design solution is summarized. This is aided with computer simulations and the results show that the scheduling polices are effective in controlling TPCS-NCS.

Sphenopalatine ganglion block in primary headaches: An American Headache Society member survey.

The sphenopalatine ganglion (SPG), in the pterygopalatine fossa, is a known current and historical target for therapeutic intervention in headache disorders because of its role in cranial autonomics and vasodilation. There remains an overall lack of well-established SPG treatment protocols, particularly with the advent of newer commercial devices. A 22 multiple-choice question survey was created to evaluate clinical practice patterns with SPG block and sent to members of the American Headache Society (AHS). Questions focused on determining indications, preferred applicators, medications applied, perceived efficacy, tolerability, and reimbursement. One hundred seventy-two of 1,346 (12.8%) AHS members participated. Ninety-three respondents (56.3%) had performed SPG blocks on 50 or fewer patients. The SphenoCath (42.4%) and the Tx360 (41.8%) were the most common methods of application. Ease of use was the top reason for provider preference in applicator type. SPG blocks were mostly used as an as-needed one-time procedure. When a scheduled protocol was used, twice weekly for 6 weeks was most common. Chronic migraine was the most commonly treated headache disorder and rated the most likely to respond to SPG block. Experienced clinicians found SPG more helpful as a stand-alone treatment and tended to report that acute relief was not predictive of enduring response. The variety of responses strongly suggests that clinicians would benefit from formalized protocols for SPG blocks. More experienced clinicians may have developed individualized protocols that they feel are more effective. The lack of evidence-based protocols contribute to clinicians not performing SPG blocks more frequently.

Network Scheduling and Control Co-Design for Multi-Loop MPC

This paper is concerned with model predictive control (MPC) for multi-loop networked control systems over shared bandwidth-limited communication networks. The plants are described by linear discrete-time systems with additive disturbances and input constraints. At each time instant, only a limited number of loops can communicate over the networks, and the scheduling sequence is determined by a network manager. Algorithms are proposed for co-designing the MPC and the scheduling protocol to stabilize all loops with conflict-free transmissions. We give conditions to ensure recursive feasibility of the optimization problems and the stability of all loops. Finally, two numerical examples show that the algorithms work well.

Nature inspired chaotic squirrel search algorithm (CSSA) for multi objective task scheduling in an IAAS cloud computing atmosphere

Task scheduling in the cloud platform seems to be the most significant issue to guarantee that cloud connectivity adequately and efficiently meets the requirements of customers. Schedulingis basically the method of mapping or assigning tasks after taking into account job features to accessible funds. An effective scheduling protocol should comply with user needs and aids a service provider perform excellent quality of service(QoS) in order to boost general application efficiency. Cloud computing is an evolving computational paradigm with a broad range of self-reliant and economically diverse computational structures. Task scheduling is a significant move to enhance cloud computing general efficiency. Task scheduling is also important in order to decrease power utilization and enhance service providers ' profitability through a reduction in handling moment. In this paper we suggest a chaotic squirrel search algorithm (CSSA) to optimally multitask scheduling in an Infrastructure as a Service (IaaS) cloud atmosphere. The methods continuously generate job plans that render the current approaches more cost-effective. In order to guarantee greater global convergence, the early eco system was produced with messy optimisation for the efficient eco-system. The suggested chaotic squirrel search algorithm was ultimately synthesised with the messy local search to enable the exploring authority to complement Squirrel search algorithm (SSA) algorithms. Other QoS conditions such as compatibility and safety for very big cases can be expanded to cover the suggested technique. A cloud simulator toolkit takes into consideration the strategy and compares the outcomes with scheduling algorithms so that ideal outcomes for several goals are achieved.

An Analytical Model for Interference Alignment in Broadcast Assisted VANETs.

Application of safety-related information interaction among vehicles has always been a research frontier in Vehicular Ad-hoc NETworks (VANETs). These messages require high real-time performance. There is a lot of research dependant on creating optimization model for communication task scheduling or routing protocols to reduce communication delay. In this paper, we analyze characteristics of safety-related information and introduce Interference Alignment (IA) technology in VANETs. To further improve routing efficiency, a data-driven assisted transmission routing and broadcast model framework for Vehicle to Vehicle(V2V) and Vehicle to Infrastructure (V2I) communication are constructed which are the basis for IA. Depending on the proposed model, we propose an optimization problem of minimizing total number of time slots required for safety information sharing in VANETs. Then a clustering algorithm is designed to narrow feasible solution space. Simulation results show that the approach can effectively reduce the number of time slots required and improve link use by 20% percent compared with no IA applied.

Frequency‐dependent fault detection for networked systems under uniform quantization and try‐once‐discard protocol

SummaryThis paper is concerned with the frequency‐dependent fault detection scheme for networked systems under uniform quantization and try‐once‐discard protocol scheduling. By considering the communication constraint and the data node scheduling, a switched system is firstly modeled to characterize the dynamic features of the whole system. The switching function of the derived system is determined by the try‐once‐discard protocol. For this class of system, a sufficient condition to ensure the exponentially ultimately boundedness is established. With the aid of some novel analysis processes, sufficient conditions to characterize the desired finite frequency performances, which transform the frequency‐domain restrictions into time‐domain conditions, are subsequently developed. Then, the fault detection filters corresponding to the transmission nodes are synthesized by solving an optimization problem. Finally, an application to VTOL aircraft is presented to illustrate the effectiveness of the proposed fault detection strategy.

Stabilizing transmission intervals and delays in nonlinear networked control systems through hybrid-system-with-memory modeling and Lyapunov–Krasovskii arguments

This article employs the hybrid-system-with-memory formalism to attain transmission intervals and delays that provably stabilize Networked Control Systems (NCSs). Nonlinear time-varying plants and controllers with variable discrete and distributed input, output and state delays along with nonconstant discrete and distributed network delays are considered. We bring together nominal system L2-stability, Uniformly Globally Exponentially Stable (UGES) scheduling protocols and linear upper bounds of network-induced output error dynamics to infer Uniform Global pre-Asymptotic Stability (UGpAS) of the closed-loop system via Lyapunov–Krasovskii arguments. Namely, we replace the Lyapunov–Razumikhin conditions and trajectory-based small-gain theorem with linear L2-gains arguments, featured in our previous works, with Lyapunov–Krasovskii functionals to prove UGpAS of interconnected hybrid systems with memory. The present methodology allows for more general delays (e.g., multiple input/output/state discrete and distributed delays) and output error dynamics (e.g., multiple discrete and distributed delays) as well as less conservative estimates of Maximally Allowable Transfer Intervals (MATIs). Our results are applicable to control problems with output feedback and the so-called large delays, that is, delays larger than the transmission intervals. In addition, model-based estimators between two consecutive updates, rather than merely the Zero-Order Hold (ZOH) strategy, are allowed for in order to prolong MATIs. Lastly, a nonlinear numerical example involving a single-link robot arm and observer–predictor-based control law is provided to illustrate our theoretical findings.

Design of Routing Protocols in IoT

IoT is an emerging technology nowadays and it has many applications in our day to day life. Through Internet of Things, millions of devices can be connected to the internet which can communicate each other by exchanging the data. For efficient transmission of packets, proper routing and scheduling alga- rhythms are required. Efficient routing and scheduling strategies ensure proper resource allocation in the network. Most of the IoT system uses the effective packet scheduling and routing concepts to enhance the performance of the network. This paper describes the concepts of various routing and scheduling protocols used in Internet of Things. Working of different protocols and its merits ands merry serial sodas sled in this art icle.

A cubic chromosome representation for patient scheduling in the Emergency Department

In healthcare institution management, hospital flow control and the prediction of overcrowding are major issues. The objective of the present study is to develop a dynamic scheduling protocol that minimizes interference between scheduled and unscheduled patients arriving at the emergency department (ED) while taking account of disturbances that occur in the ED on a daily basis. The ultimate goal is to improve the quality of care and reduce waiting times via a two-phase scheduling approach. In the first phase, we used a genetic algorithm (based on a three-dimensional cubic chromosome) to manage scheduled patients. In the second phase, we took account of the dynamic, uncertain nature of the ED environment (the arrival of unscheduled patients) by continuously updating the schedule.

Collision Recognition in Multihop IEEE 802.15.4-Compliant Wireless Sensor Networks

Collisions caused by the hidden terminal effects may result in severe packet corruption and performance degradation in multihop IEEE 802.15.4-compliant wireless sensor networks (WSNs). In order to avoid such collisions through scheduling protocols, it is important to first recognize these collisions by distinguishing them from some other noncollision cases (e.g., path loss, multipath fading, shadow fading, and IEEE 802.11 interference), which may also lead to similar consequences. In this paper, we focus on the collision recognition problem in multihop IEEE 802.15.4-compliant WSNs. First, through a series of measurements of the error properties in various collision and noncollision scenarios, we investigate the statistical behaviors of error patterns including the bit error rate and error position distribution, which reveal obvious differences between collision and noncollision cases in terms of bit- and symbol-level error position distribution. Based on these observations, we further propose a machine learning-based collision recognition mechanism by inserting some redundant blocks in a data frame. The inserted blocks are known to both the sender and receiver, thereby it enables the receiver to recognize the error patterns only according to the redundant sequences. Moreover, a mutual information-guided byte selection technique is also provided to effectively improve the recognition accuracy. Finally, the proposed mechanism is verified under three different transmission environments. The experimental results show that the proposed mechanism achieves good recognition accuracy over 90% with 94% coding efficiency.

Energy efficient protocol for routing and scheduling in wireless body area networks

An energy efficient protocol for routing and scheduling in wireless body area networks is proposed by considering node energy, path loss, traffic type, and other relevant factors. First, a channel competition procedure is proposed to reduce network flooding, making use of the related information that sensor nodes collected in the initialization phase. Then, energy abundant routes are selected according to the node type and energy consumption in routing setup phase. Finally, an adaptive slot assignment method is designed to meet requirements of data rate and priority in slot assignment phase. The simulation results show that the proposed protocol not only save energy, but also improve the channel utilization.