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• The performance of SCLEACH, SCPEGASIS, SCTEEN is analyzed. • Single report is enough to transfer to the sink, to avoid redundant reports. • Proposed protocols have been compared with k-d tree algorithm. • Five parameters are considered for the analysis. SCHRP model takes less time to measure the parameters of the network. In Wireless Sensor Networks (WSNs), the most significant task is to gather the data from the sensor nodes available in specific region available in event sensing field. The nodes in WSNs are energy constrained. To enhance the lifetime of WSNs, energy efficient protocols are needed. Spatial Correlation based Low Energy Adaptive Clustering Hierarchy (SCLEACH), Spatial Correlation based Power-efficient Gathering in Sensor Information Systems (SCPEGASIS), Spatial Correlation based Threshold Sensitive Energy Efficient Sensor Network Protocol (SCTEEN) are well-designed solutions to rectify this problem. These protocols minimize the overall dissipation by means of individual sensor nodes located in the network. Spatial correlation based Hierarchical Routing Protocols (SCHRP) adapt clustering concept and enhance the energy efficiency and the performance of over all network. The Performance of SCHRP model is compared with existing LEACH and PEGASIS, TEEN protocols and results have been taken for various parameters such as End-to-End delay, Packet drop, Packet delivery ratio, Throughput, Energy Efficiency and Energy Consumption. The proposed SCLEACH has 6.35% higher energy efficiency than the existing LEACH protocol. The impact of the proposed protocols are evaluated using various parameters and compared with k-d tree algorithm. The importance of spatial correlation based routing concept is analyzed with respect to k-d tree algorithm and the simulation results have been taken using Network Simulator tool. [ABSTRACT FROM AUTHOR]

Constand-round secure multi-party computation enables a group of mutually distrustful parties to jointly compute a function of their inputs in a constant-round of communication. In recent years, the constant-round secure multi-party computation protocol has improved the efficiency of the online phase by completing the multiplication computation in advance of the online phase through the Beaver triples generated in the preprocessing phase. However, the preprocessing phase of these protocols is extremely overhead-intensive and there is room for improvement. In this paper, we propose an active, constant-round secure multi-party computation (MPC) protocol which can tolerate arbitrary n − 1 corruptions. At the high level, we follow the Tiny-OT protocol and the unauthenticated garbling for garbled circuits in the preprocessing phase presented by Carmit Hazay and Peter Scholl (ASIACRYPT 2017). Particularly, we first present a new optimized Tiny-OT protocol for generating Beaver (AND) triples which is more efficient than the previous protocol, and then combine the information generated by Tiny-OT to construct an unauthenticated garbled circuit. To be precise, we also reduce the number of commitments and hash function calls in the correctness check of AND triples, and avoid using additional OT operations to compute the circuit, thus further improving communication efficiency. Our new constant-round MPC protocol has a communication complexity O (| C | Bnk) per party. Moreover, we further provide solutions to the open problem of introducing the half-gate technique into multi-party distributed garbled, which will reduce half size of the garbled table per gate. [ABSTRACT FROM AUTHOR]

One of the most vastly used protocols to protect services traffic like the web and email is Transport Layer Security (TLS). In 2018 the Internet Engineering Task Force (IETF) standardized the latest version TLS 1.3, Introduced a significant enhancement in the protocol performance, and presented some new features. One of the new features is zero round trip-time (0-RTT) handshake mode, where the client can send the application data to the server within the handshake messages before the TLS connection is fully established. However, this application data is replayable. The replay attacks in 0-RTT handshake mode have been studied, and several mechanisms are proposed for protection, these proposed mechanisms are not able to prevent replay attacks when the server functionality is provided by a distributed environment such as multiple servers in a cloud computing environment or a CDN. This paper introduces TLS Guard as a new mechanism that extends TLS 1.3 to prevent replay attacks in a distributed environment. We evaluated a prototype TLS Guard implementation in controlled experiments and showed that its effect comes at the cost of some CPU overhead. More importantly, we showed that TLS Guard is scalable and tolerates faults without any required changes on the client side. [ABSTRACT FROM AUTHOR]

The growth in the usage of the Internet of Things (IoT) has resulted in the deployment of diverse networks. However, the multiple networking interfaces and embedded protocols pose a significant challenge to communication compatibility. To tackle this problem and establish a flexible networking framework, we propose the implementation of a general-purpose message parser utilizing a recurrent neural network model with stack memory (RNN-SM). This parser has the ability to extract crucial keywords from the various communication network messages, which are trained on multiple network protocol specifications. During the training phase, the RNN-SM predicts candidate keywords and cross-references them with predefined keywords in an expandable dictionary, thus improving the accuracy of keyword extraction. Additionally, we have introduced the concept of minimum prediction fork level as a hyperparameter to balance the simplicity and flexibility of the RNN-SM. The proposed parser proves to be an effective solution in facilitating smooth communication between multiple devices and also has the added benefit of filtering out noise. The RNN-SM's robust keyword extraction capability holds up even in noisy environments, making it a reliable solution for the compatibility challenges posed by the IoT. [ABSTRACT FROM AUTHOR]

The in-vehicle voltage-based intrusion detection system (VIDS) can recognize the identity of the ECUs and detect the physical layer attacks that cannot be detected by the content-based or frequency-based IDS. However, recent research in VIDS has discovered an overlapped voltage attack that can bypass the existing VIDS by generating overlapped voltage signals from two compromised ECUs to distort the fingerprint of the target ECU. The existing solutions need to change the communication protocol or network topology to mitigate the attack, which may involve additional development costs or scheduling mechanisms to coordinate the tasks. In this paper, motivated by not changing the network topology and protocols, we propose an improved VIDS that can efficiently detect the overlapped voltage attack of the in-vehicle CAN network. Before retraining the VIDS classifier model, we add the mechanism for detecting and filtering overlapped signals in the voltage samples by applying the Long Short-Term Memory (LSTM) autoencoder network to preserve the fingerprint characteristics of the benign waveform in the original samples. First, we establish an LSTM autoencoder model with benign voltages collected in a usual scenario and then apply the automatic thresholding approach to obtain the threshold to separate the overlapped and benign voltages. Next, we filter the overlapped voltages and extract the fingerprint features from the filtered voltage samples to predict the classification of the masquerade CAN packet during the attack. Finally, we evaluate the performance and attack success rate of the proposed VIDS on a CAN bus testbench. The results show that the proposed VIDS can effectively detect the overlapped voltage attack and identify the compromised ECU mimicking the distorted voltage fingerprints with an accuracy of 99.4%. The attack success rate of the proposed VIDS drops to 0 ∼ 18%, which is about 60 ∼ 95% for the existing VIDS. [Display omitted] • We propose an improved in-vehicle VIDS to mitigate the overlapped voltage attack. • We present an LSTM-AE-based examination mechanism to protect VIDS from poisoning. • We evaluate VIDS and prove the effectiveness of overlapped voltage attack detection. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to examine the impact of vigorous intensity, high dose exercise (DEI) on cannabis use among stimulant users compared to a health education intervention (HEI) using data from the Stimulant Reduction Intervention using Dosed Exercise, National Institute of Drug Abuse National Drug Treatment Clinical Trials Network Protocol Number 0037 (STRIDE).Methods: Adults (N = 302) enrolled in the STRIDE randomized clinical trial were randomized to either the DEI or the HEI. Interventions included supervised sessions three times a week during the Acute phase (12 weeks) and once a week during the Follow-up phase (6 months). Cannabis use was measured at each assessment via Timeline Follow Back and urine drug screens. Cannabis use was compared between the groups during the Acute and Follow-up phases using both the intent-to-treat sample and a complier average causal effects (CACE) analysis.Findings: Approximately 43% of the sample reported cannabis use at baseline. The difference in cannabis use between the DEI and HEI groups during the Acute phase was not significant. During the Follow-up phase, the days of cannabis use was significantly lower among those in the DEI group (1.20 days) compared to the HEI group (2.15 days; p = 0.04).Conclusions: For those who adhered to the exercise intervention, vigorous intensity, high dose exercise resulted in less cannabis use. Results suggest that there were no significant short-term differences in cannabis use between the groups. Further study on the long-term impact of exercise as a treatment to reduce cannabis use should be considered. [ABSTRACT FROM AUTHOR]

WSN became a key technology for ubiquitous living and remains an active research due to wide range of applications. Energy awareness is a critical design issue in WSN. Clustering is the most popular energy efficient technique and provides various advantages like energy efficiency, lifetime, scalability and less delay; but it leads to hot spot problem. To overcome this, unequal clustering is proposed. In unequal clustering, the cluster size varies proportionally to the distance to Base Station (BS). Absence of recent and detailed survey papers in unequal clustering approaches stimulated us to perform this study. In this paper, a comprehensive survey of various unequal clustering approaches with their objectives, characteristics etc., is presented. Also, the classifications of unequal clustering approaches are made and compared based on various cluster properties, Cluster Head (CH) properties and clustering process. [ABSTRACT FROM AUTHOR]

Application of health-care networks is becoming more and more attractive. Electronic-monitoring and movable cameras are the key parts of health - care information collection by mobile electronic devices. Healthy public domain is developed by intellectual approaches. A wide variety of data from electronic-monitoring and movable camera will be stored and shared with continued demand for health-care service demands (e.g., ECG service, personal pulse service information). However, health-care networks and devices usually share the same frequency spectrum that results in inflexible access sharing. Frequency spectrum access sharing makes the challenge of how best to use electronic health-care information and commutation protocol. We design an priority considerations health-care networks and commutation protocol to enhance quality of access sharing and the users' health-care accuracy by stochastic sharing and protocol optimization. The numerical results show that the health-care networks and protocol can enhance capacity of access sharing for users and spectrum utility of networks. [ABSTRACT FROM AUTHOR]

Abstract Routing in Wireless Sensor Networks (WSNs) is the most significant and the challenging issue for the researchers in terms of enhancing its performance in terms of network lifetime, energy efficiency, scalability, connectivity, throughput, etc. They have the incredible capability to interact and gather data from any physical environment with help of routing protocols. Many routing protocols based solutions have been proposed in the recent years for accomplishing the preferred level of performance in WSNs for these issues. The hierarchical heterogeneous cluster based energy efficient routing protocols are more efficient as compared to flat and location based routing protocols due to the presence of nodes heterogeneity in terms of energy level of sensor nodes which enhances the lifetime of the network. The most recent trend that extensively enhances the functionality and the performance of WSNs is the use of mobile sensor nodes. In this paper, the authors proposed a novel concept regarding mobile sensor nodes is proposed called Mobile Energy Aware Cluster Based Multi-hop (MEACBM) routing protocol for hierarchical heterogeneous WSNs which selects CHs on the basis of newly proposed probability equation which selects only that sensor node as Cluster Head (CH) which has the highest energy among other sensor nodes by introducing a new term S(i).E in the equation. It considers hierarchical heterogeneous clustering considering three levels of sensor nodes; multi-hoping for inter-cluster communication and connectivity of sensor nodes within the whole network area. In MEACBM, after the deployment of sensor nodes and formation of clusters, the whole network area is divided into sectors and inside each sector a mobile sensor node is placed which act as Mobile Data Collector (MDC) for collecting data from CHs. This technique helps in significantly reducing the energy consumption of sensor nodes for transferring information to the Base Station (BS). Simulation performance based results indicates the effectiveness of MEACBM routing protocols by comparing it with other contemporary cluster based routing protocols in terms of network lifetime, stability, throughput, number of CHs and number of dead nodes. [ABSTRACT FROM AUTHOR]

Abstract We introduce the estimation protocol for detecting the temperature of the transverse vibrational modes of linear ion crystal. We show that thanks to the laser induced laser coupling between the vibrational modes and the collective spin states the estimation of the temperature is carried out by set of measurements of the spin populations. We show that temperature estimation protocol using single ion as a quantum probe is optimal in a sense that the set of state projective measurements saturate the fundamental Cramer–Rao bound. We find a plateau of the maximal temperature sensitivity using ion chain as a quantum probe. Moreover, we show that the non-classical part of the quantum Fisher information could leads to enhancement of the temperature sensitivity compared to the single ion case. Highlights • Estimation of the temperature of the transverse vibrational modes of linear ion crystal. • The methods rely on using spin–phonon coupling in a system of trapped ions. • The estimation precision is quantified in terms of quantum Fisher Information. [ABSTRACT FROM AUTHOR]

Abstract This paper is concerned with the distributed resilient filtering for nonlinear time-varying systems over sensor networks with communication protocol constraints. In order to prevent data collisions over sensor networks, the data transmission between each node and its neighboring ones is realized through the Round-Robin/stochastic protocol, which guarantee that only one neighboring node is permitted to send message at each transmission instant. Moreover, the resilient filter is designed to suppress the adverse effects induced by imprecision of filter parameters. By means of the stochastic analysis approach and recursive linear matrix inequality technique, several sufficient conditions are established to ensure that the state estimation error system subject to communication protocols satisfies the prescribed H ∞ performance constraint over a finite-horizon. Finally, a numerical example is presented to show the feasibility and effectiveness of the proposed results. Highlights • Protocols are employed in sensor networks to prevent data collisions. • The distributed filter is designed for time-varying systems over sensor networks. • The resilient filter is applied to reduce the adverse effects caused by imprecision. • A recursive algorithm is proposed to derive parameters of distributed filter. [ABSTRACT FROM AUTHOR]

Abstract Broadcast of beacon messages including geographic coordinates, node speeds, and directions are among the most commonly used methods in routing protocols of VANETs to obtain neighboring positions. Broadcast of periodic beacon messages in fixed time intervals will reduce network performance due to increased channel load and contention. In this paper, an adaptive update strategy for sending beacon messages according to the VANETs' characteristics (position, speed, and direction) and the nature of broadcast wireless channel in an opportunistic routing strategy is studied. It is based on two rules: 1) an estimation of the lifetime of the links between vehicles' beacon messages are sent after the expiration of the estimated time to inform their local topology and 2) if the forwarding set of consecutively received data packets is changed, a beacon message is sent to maintain the accuracy of the topology. The simulation results show that the proposed strategy significantly reduces the cost of routing and improves network performance in terms of packet-delivery ratios, average end-to-end delay, and routing overhead. [ABSTRACT FROM AUTHOR]

Abstract 1 1 Video demonstrations and a video presentation providing a summary of the paper can be found at https://goo.gl/EDvxhk. Low-cost Unmanned Aerial Vehicles (UAVs), also known as drones, are increasingly gaining interest for enabling novel commercial and civil Internet-of-Things (IoT) applications. However, there are still open challenges that restrain their real-world deployment. First, drones typically have limited wireless communication ranges with the ground stations preventing their control over large distances. Second, these low-cost aerial platforms have limited computation and energy resources preventing them from running heavy applications onboard. In this paper, we address this gap and we present Dronemap Planner (DP), a service-oriented cloud-based drone management system that controls, monitors and communicates with drones over the Internet. DP allows seamless communication with the drones over the Internet, which enables their control anywhere and anytime without restriction on distance. In addition, DP provides access to cloud computing resources for drones to offload heavy computations. It virtualizes the access to drones through Web services (SOAP and REST), schedules their missions, and promotes collaboration between drones. DP supports two communication protocols: (i.) the MAVLink protocol, which is a lightweight message marshaling protocol supported by commodities Ardupilot-based drones. (ii.) the ROSLink protocol, which is a communication protocol that we developed to integrate Robot Operating System (ROS)-enabled robots into the IoT. We present several applications and proof-of-concepts that were developed using DP. We demonstrate the effectiveness of DP through a performance evaluation study using a real drone for a real-time tracking application. [ABSTRACT FROM AUTHOR]

Abstract To cope with the diversity of Internet of Things (IoT) requirements, a large number of Medium Access Control (MAC) protocols have been proposed in scientific literature, many of which are designed for specific application domains. However, for most of these MAC protocols, no multi-platform software implementation is available. In fact, the path from conceptual MAC protocol proposed in theoretical papers, towards an actual working implementation is rife with pitfalls. (i) A first problem is the timing bugs, frequently encountered in MAC implementations. (ii) Furthermore, once implemented, many MAC protocols are strongly optimized for specific hardware, thereby limiting the potential of software reuse or modifications. (iii) Finally, in real-life conditions, the performance of the MAC protocol varies strongly depending on the actual underlying radio chip. As a result, the same MAC protocol implementation acts differently per platform, resulting in unpredictable/asymmetrical behavior when multiple platforms are combined in the same network. This paper describes in detail the challenges related to multi-platform MAC development, and experimentally quantifies how the above issues impact the MAC protocol performance when running MAC protocols on multiple radio chips. Finally, an overall methodology is proposed to avoid the previously mentioned cross-platform compatibility issues. [ABSTRACT FROM AUTHOR]

As the use of Wireless Sensor Networks grows, many challenging issues with these networks arise. The utilization of power consumption is one of the most significant issue due to the limited energy constraints of the individual sensor nodes. This limitation imposes a challenge to design the best energy-efficient routing mechanism. This work presented an Energy-Efficient Gossiping protocol (EEGossip) that routes data to the sink by choosing the optimal next node. EEGossip uses Chebyshev distance, residual energy and the sink distance as factors when determining the optimal next node. The result of the proposed work has shown that the proposed protocol improves the total energy consumption of the network and leverages the network lifetime since it decreases the computational overhead and ensures that the best next node is chosen. [ABSTRACT FROM AUTHOR]

Wireless sensor networks is made up of many tiny nodes that has the ability to measure physical phenomena and send the collected measurements to the sink node using multiple-hop protocol with short range transmission. One of the main factors that can be considered to increase the sensor network life is routing protocol. The main goal of routing protocol is to select the most optimal path and make decision of sending the gathering data to the sink node. Inefficient routing protocol leads to more re-transmission of data which consume more energy.Thus, a careful and comprehensive performance analysis of the routing protocols used in any wireless sensor network is required. The main goal of this paper is to study the performance of the RPL protocol under three different MAC protocols named; ContikiMac, CXMAC, NullRDC in terms of end-to-end delay, packet delivery ratio and power consumption to find the best behaviour of the RPL routing protocol under the MAC protocols effect. The results show that NullRDC is better in terms of latency while the ContikiMac outperforms the others in terms of power consumption. [ABSTRACT FROM AUTHOR]

Abstract Boosted by trends such as Industrial IoT and Industry 4.0, industrial Ethernet networks (EtherNet/IP, EtherCAT and PROFINET IRT as top-3 players) have been commonly deployed in industrial automation. The aim of this paper is to provide a practical guideline for selecting the right protocol in industrial networked control systems (NCSs) by comparing the performance of these protocols. Communication delays are discussed, formulated and evaluated with a study of a typical NCS. Simulation results demonstrate that with different frame packing, media access scheme, etc., EtherNet/IP, EtherCAT and PROFINET IRT offer different levels of real-time capabilities which lead to different control performance. Highlights • EtherCAT, PROFINET IRT and EtherNet/IP offers various real-time capabilities. • A generic process is established to evaluate communication and control performance. • A guideline to choose the right protocol for a networked control system is provided. [ABSTRACT FROM AUTHOR]

Abstract Previous task mapping assumes that applications directly fetch data on remote nodes and build up their energy efficient mapping based on pattern of the NoC traffic. However, the data movement is actually managed by a cache coherence mechanism that executes a much more complicated protocol under application layer to guarantee data correction. Thus, we propose an energy efficient task mapping referring the protocol layer, rather than application layer, to precisely model protocol activities and energy dissipation. By a probabilistic description of cache accessing, we find a efficient method to convert application activities to energy consumption, generating an energy evaluation as a global optimization goal. We also propose a task mapping algorithm to minimize the energy consumption by referring activity intensity of the protocol. The experimental results show that the proposed energy model achieves a precision with less than 2% error and provides a credible quantitative criterion for energy optimization of cache coherence protocols. Comparing to application-layer optimization, our task mapping can obtain 20% energy saving and 15% latency reduction on average. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we present a finite-block-length comparison between the orthogonal multiple access (OMA) scheme and the non-orthogonal multiple access (NOMA) for the uplink channel. First, we consider the Gaussian channel, and derive the closed form expressions for the rate and outage probability. Then, we extend our results to the quasi-static Rayleigh fading channel. Our analysis is based on the recent results on the characterization of the maximum coding rate at finite block-length and finite block-error probability. The overall system throughput is evaluated as a function of the number of information bits, channel uses and power. We find what would be the respective values of these different parameters that would enable throughput maximization. Furthermore, we analyze the system performance in terms of reliability and throughput when applying the type-I ARQ protocol with limited number of retransmissions. The throughput and outage probability are evaluated for different blocklengths and number of information bits. Our analysis reveals that there is a trade-off between reliability and throughput in the ARQ. While increasing the number of retransmissions boosts reliability by minimizing the probability of reception error, it results in more delay which decreases the throughput. Nevertheless, the results show that NOMA always outperforms OMA in terms of throughput, reliability and latency regardless of the users priority or the number of retransmissions in both Gaussian and fading channels. [ABSTRACT FROM AUTHOR]

Abstract Mobile sink has been used by many routing algorithms to improve the network lifetime in wireless sensor networks. Sink mobility brings new challenges to the sensor network. It suggests that sink position is continuously propagated through the network area to keep all sensor nodes updated with the direction of forwarding data to the sink. Unfortunately, frequent sink position updates can lead to both high-energy consumption and increased collisions in the network. In this paper, a new routing algorithm for wireless sensor networks is proposed, which uses a virtual multi-ring shaped infrastructure to advertise the mobile sink position to the network. In addition, the proposed algorithm supports several mobile sinks in the network. Simulation results indicate that the proposed algorithm reduces energy consumption and delay, and prolongs the sensor network lifetime when compared with the other similar algorithms. [ABSTRACT FROM AUTHOR]

Abstract We consider an ad hoc radio network in which nodes perform some distributed algorithms. We provide a framework, that at the cost of increasing time complexity, prevents an outer, passive adversary from gaining significant information about the execution of the algorithm. The main idea we utilize is adding some extra obfuscating rounds to conceal the real execution. Despite the fact that we assume a relatively weak model of the adversary, trying to solve the problem, we encounter several non-trivial issues. First of all, the proposed method needs to be universal and work in on-line mode. Moreover, the method should entail possibly small time overhead and provide a provable security. Finding a satisfactory solution is particularly difficult due to the very restrictive, in terms of nodes capabilities, communication model. The main result presented in this paper is an efficient general method for obfuscating an execution of any underlying algorithm and its rigid analysis. We provide security guarantees against a passive adversary, with an ability of eavesdropping every transmission in the network, that aims at learning the execution of the algorithm. We also present a specialized algorithm for a secure listing of all present (active) nodes, that does not reveal any substantial information about the network to the outer adversary. [ABSTRACT FROM AUTHOR]

Abstract In a globalized world, the mobile user roams frequently from one place to other. Global mobility network provides roaming services to a mobile user when the mobile user is away from his home network and wants to avail the services of the foreign network. Roaming authentication protocol supports authentication between the mobile user and the foreign server in global mobility network so that the malicious user can not get access the roaming services in the foreign network. Moreover, privacy-preserving authentication between the mobile user and the foreign server is an essential technology for the secure access of global mobility network because mobile user's privacy protection has become a major issue due to increasingly misuse of consumer's private data by various organizations and individuals. Many privacy-preserving two-factor authentication protocols have been proposed to provide secure roaming services in global mobility network but they failed to support privacy and security while ensuring efficient typo detection by the smart card. We propose a privacy-preserving secure two-factor authentication protocol for roaming service in global mobility network which not only ensures the privacy of the mobile user but also provides efficient typo detection using fuzzy verifier and honeyword technique. Moreover, the proposed protocol overcomes the problem of desynchronization attack using public key encryption technique based on quadratic residue assumption with low computational load at the mobile user. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we propose two relay selection methods to enhance system outage performance for energy harvesting (EH) based two-way relaying protocols in wireless adhoc networks. In the proposed protocol, two source nodes communicate with each other via the assistance of multiple decode-and-forward (DF) relays using three-phase digital network coding. At the first and second phases, two sources broadcast their data to the relays. Employing a power-splitting model, the relays would harvest energy from radio frequency (RF) signals of the sources to transmit the data at the third phase. We propose a simple partial relay selection (PRS) method and an opportunistic relay selection (ORS) method to enhance the reliability of data transmission at the cooperative phase. For performance evaluation, we derive exact and asymptotic expressions of the system outage probability (SOP) for the proposed protocols over block Rayleigh fading channels. Finally, Monte Carlo simulations are presented to verify the theoretical derivations as well as to compare the performance of the proposed protocols with that of the random relay selection protocol. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we investigate the finite-time consensus control problem for heterogeneous nonlinear multi-agent systems (MASs) subject to nonlinear uncertainties. In the case of a connected and undirected communication graph, a new finite-time consensus control algorithm for leaderless MASs is presented. The designed consensus protocol can guarantee that the steady state error of every two agents converge to zero in a finite-time. Compared with some existing studies, in which the upper bounds of uncertainties are assumed to be some positive constants, the upper bound assumption conditions of uncertainties are relaxed to be some positive functions. Finally, a numerical example and a practical model are presented to demonstrate the effectiveness of the proposed consensus control method. [ABSTRACT FROM AUTHOR]

Abstract Mobile Wireless Sensor Network (MWSN) is a set of interconnected mobile sensor devices forming a dynamic network without a fixed administration. MWSN is used in various domains, such as disaster detection, medical systems, military applications, vehicular communications, and in other sensitive applications. Compared to the classical sensor networks, MWSNs involve an additional constraint consisting of the topology change frequency caused by the mobility of sensor devices. This influences highly the energy consumption and consequently the network reliability. In this paper, we take in charge this important issue and we contribute by the proposition of an efficient and energy-aware routing protocol. The proposed protocol operates for both request and event oriented MWSN applications. It introduces the sensor device mobility history in order to build-up stable routing paths, and incorporates a novel technique of dissimulation in order to exchange the mobility control messages without overhead. We have evaluated the performances of the proposed protocol through simulations, in which it provides effective results in terms of energy consumption and load-balancing. [ABSTRACT FROM AUTHOR]

Abstract Temporal/spatial disruptions and IP changing caused by host mobility lead the user applications to fail. This remains a problem due to the ossification of the TCP/IP protocol stack and the lack of support of existing solutions in enabling connection failure tolerance at application layer. To preserve integrity and transmission consistency upon erroneous communication events caused by host mobility, enabling mobility awareness is a key requirement for the current user applications. In this paper, we provide a comprehensive study on mobility-aware application protocols that ensure reliability and resiliency for long-lived TCP sessions established between clients and severs that migrate across different wireless IP networks on the Internet. To this end, we modeled and simulated such protocols through general-purpose state machines, which we conceived regarding the Socket semantic to resume session from broken connections. Simulations results revealed how internal and external factors, i.e., protocol design decisions and mobile environment conditions, respectively, can and cannot influence performance. When comparing results with TCP-Migrate – a well-known transport layer mobility protocol, handover delays in application protocols are longer in single jumps between mobile client and stationary server, but shorter in double jumps, when both client and server are mobile entities. [ABSTRACT FROM AUTHOR]

Abstract This paper describes the overlay protocol Chord using the formalism of Abstract State Machines. The formalization concerns Chord actions that maintain ring topology and manipulate distributed keys. We define a minimal set of deterministic constraints and prove that they guarantee the stability of the topological structure of the network and the consistency of data handling. [ABSTRACT FROM AUTHOR]

Abstract Bit commitment is an important tool in the design of many secure cryptographic protocols, such as coin flipping, zero-knowledge proof, and secure computation. In this paper, we present a computationally light-weight bit commitment protocol over a noisy channel. For the security of the proposed protocol, we show that the receiver has almost no information about the committer's secret due to unpredictability of the noises in the communication channel. Hence, the security of our bit commitment protocol does not depend on hard problems; it is information-theoretically secure. Furthermore, the protocol needs only exclusive-or operations. Thus, it is computationally light-weight, and it can be used in the devices whose computing resources are limited. [ABSTRACT FROM AUTHOR]

Highlights • This study investigates what and how source information is attended to and utilized in the SCWT. • The findings indicated that the SCWT required knowledge-transforming process. • Test-takers could rely on the conceptual information for story interpretation and story development. • Test-takers could directly employ or imitate the noticed textual information in the continued part. • Teachers' perceptions of source use in the SCWT were also examined. Abstract The story continuation writing task (SCWT) is a newly developed type of integrated writing task that is observed to be able to stimulate language learning efficiently. Nevertheless, little is known with respect to what source knowledge test-takers notice and how they process the noticed information during the task. This paper contributes to the literature by investigating what and how source information is attended to and utilized in SCWT. Think-aloud protocols and retrospective interviews were collected from 19 students. In addition, nine teachers were interviewed for their perceptions about source use in SCWT. Findings indicated that the SCWT required knowledge-transforming process, as the test-takers attended to both conceptual and textual aspects of the source text. The SCWT represented a unique integrated writing task, because test-takers could rely on the conceptual information for source interpretation and writing development. They could directly employ or imitate the noticed textual information in the continuation. The implications of adopting SCWT as an integrated writing task for assessing students are discussed. [ABSTRACT FROM AUTHOR]

Abstract The work presented in this paper proposes an efficient routing protocol named AHP-based Multimetric Geographical Routing Protocol (AMGRP) as it adopts an Analytical Hierarchical Process (AHP) while considering multiple routing criteria such as mobility metric, link lifetime, node density and node status which have been accepted as crucial factors for better performance of a protocol. The protocol implements the computed single-weighing function to identify a next hop node within a defined range which can ensure an enhanced forwarding process. The simulation results in the paper have proved that the designed protocol performs better when compared with GPSR and SLD-GEDIR protocols in an obstacle modelled urban vehicular environment. [ABSTRACT FROM AUTHOR]

Abstract Offloading data traffic from Infrastructure-to-Device (I2D) to Device-to-Device (D2D) communications is a powerful tool for reducing congestion, energy consumption, and spectrum usage of mobile cellular networks. Prior network-level studies on D2D data offloading focus on high level performance metrics as the offloading efficiency , and take into account the radio propagation aspects by using simplistic wireless channel models. In this work, we consider a D2D data offloading protocol tailored to highly dynamic scenarios as vehicular environments, and evaluate its performance focusing on physical layer aspects, like energy consumption and spectral efficiency. In doing this, we take into account more realistic models of the wireless channel, with respect to the simplistic ones generally used in the previous studies. Our objective is twofold: first, to quantify the performance gain of the considered D2D offloading protocol with respect to a classic cellular network, based on I2D communications, in terms of energy consumption and spectral efficiency. Second, to show that using simplistic channel models may prevent to accurately evaluate the performance gain. Additionally, the use of more elaborated models allows to obtain insightful information on relevant system-level parameters settings, which would not be possible to obtain by using simple models. The considered channel models range from widely used models based on deterministic path loss formulas, to more accurate ones, which include effects like multipath fading and the associated frequency selectivity of wideband channels. These models have been proposed and validated, in the recent years, through large-scale measurements campaigns. Our results show that the considered protocol is able to achieve a reduction in the energy consumption of up to 35%, and an increase in the system spectral efficiency of 50%, with respect to the benchmark cellular system. The use of different channel models in evaluating these metrics may result, in the worst case, in a sixfold underestimation of the achieved improvement. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the consensus problem of multi-agent systems (MASs) described by linear dynamic models. In order to avoid using the global information and reduce communication burden, the distributed adaptive event-based control approach is presented. Some novel triggering functions and control protocols are designed. The obtained results show that consensus can be achieved only with local information and communicating with neighbors continually is avoided as well. In addition, the Zeno-behavior for the concerned closed-loop system is excluded. Finally, a numerical example is provided to validate the availability of the obtained theoretical results. [ABSTRACT FROM AUTHOR]

Abstract The Threshold-based Low-energy Adaptive Clustering Hierarchy (T-LEACH) protocol declares that cluster heads do not have to turn over every round but rather every batch of rounds. In other words, nodes keep serving as cluster heads as long as their energy is higher than a threshold energy. This article imposes upon major drawbacks of T-LEACH protocol and presents a Modified Threshold-based Cluster Head Replacement (MT-CHR) protocol. In the MT-CHR protocol, a new probability of being a cluster head, for any node in any round, has been proposed which agrees fairly with the assumptions introduced in LEACH protocol. Moreover, a new expression for threshold energy is proposed in which delaying the first node death and avoiding any data loss are taken into consideration. The performance of MT-CHR is evaluated using alive nodes, network lifetime, as well as network utilization performance metrics. The results are further compared with those obtained importantly from LEACH and T-LEACH protocols and the contributions of MT-CHR protocol are extremely impressive. As far as the real sensor network is concerned, the MT-CHR protocol is highly applicable and very effective as long-lasting networks are ascertained. [ABSTRACT FROM AUTHOR]

Abstract An important objective of cryptographic schemes is to withstand various attacks, including leakage attacks. Otherwise, leakage of the secret key may cause serious threats to the security of computer systems. However, leakage attacks have not received adequate attention in the literature. For example, most of the existing security protocols in the wireless sensor networks (WSNs) lack the consideration of leakage attacks. Instead, they are only designed in the traditional security model, in which an adversary is assumed not to obtain any information of the internal secret states. Obviously, this is not ideal because partial information of the secret key may be leaked in practice due to side channel attacks or fault injection attack. In this paper, we propose a new construction of secure continuous leakage-resilient certificate-based signcryption (CBS) scheme with access control without using bilinear pairings, and its security can be proved based on the assumptions that solving the classical decisional Diffie-Hellman problem and discrete logarithm problem is infeasible. We then propose a novel certificate-based access control scheme for the WSNs. The analysis shows that our construction not only achieves high computational efficiency in the continuous leakage setting, but also has superior performance regarding communication efficiency and storage requirement. [ABSTRACT FROM AUTHOR]

Abstract Intelligent Transportation Systems use Vehicular Ad-hoc Networks to improve road safety. Dedicated Short Range Communications (DSRC or IEEE 802.11p) and Wireless Access in Vehicular Environments (WAVE or IEEE 1609 protocol suite) are the two important standards that govern communication in VANETs. However, DSRC based VANETs cannot guarantee to achieve the Quality of Service (QoS) requirements like reliability and latency under high vehicle density scenario due to network congestion. This paper studies the congestion behavior of IEEE802.11p/1609.4 based Medium Access Control by varying vehicle density in urban and highway conditions. Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) is the default medium access mechanism in WAVE MAC. The metrics chosen for evaluating the performance of CSMA/CA are the average end-to-end delay, average throughput, packet delivery ratio, packet loss ratio and the number of packets lost. The simulation is carried out for both urban and highway scenario under varying vehicle density and communication load. The Simulation is performed using Omnet++ and SUMO based veins framework. The simulation results show that under high vehicle density and high communication load, CSMA/CA fails to meet the required QoS. [ABSTRACT FROM AUTHOR]

Abstract Wireless Sensor Networks (WSNs) have emerged as one of the prominent area of research in the recent times. Sensor-MAC (S-MAC) protocol is one of the Medium Access Control(MAC)protocols, which follows the idea of periodic listen and sleep. In other words, node is active till the time it receives the data packets, otherwise it goes in sleep mode by turning its radio off. However, this protocol lacks in energy conservation due to unnecessary listening to the channel in idle mode. In this paper, we have proposed a new analytical model in which energy is reduced on the basis of the activities it performs in the active mode. A comparison is made between all the different possibilities which can occur at a node, when it listens unnecessarily to the medium. Various energy consuming modes of S-MAC protocol such as transmission, reception, sensing and listening are considered. The proposed work results in the minimizing the energy and reducing the delay in time as compared to that of basic S-MAC protocol. [ABSTRACT FROM AUTHOR]

Abstract In this work, we investigate the pilot contamination problem in multi-cell massive multi-input multi-output (MIMO) systems. The conventional approaches to address pilot contamination for multi-cell MIMO systems impose orthogonal pilots constraint across multiple users and cells, which leads to bandwidth inefficiency under large number of active users. We propose an uplink (UL) transmission protocol in which the pilot segments of users partially overlap across cells and even overlap with data from other cells, which provides more freedom in system designing. We also apply semi-blind algorithms at base station (BS) in order to separate the data streams of each user. Our analysis shows that semi-blind receiver removes pilot contamination effectively under large UL data length. The simulation results demonstrate that the performance of the proposed protocol with semi-blind receiver employing Constant Modulus Algorithm (CMA) is superior as compared to the existing schemes. [ABSTRACT FROM AUTHOR]

In unsecured 6LoWPANs, the nodes can be easily identified by their IPv6 as well as MAC addresses. An adversary can snoop (and later, spoof) these addresses, thereby posing a major threat against the node’s identity and communication integrity. Such threats necessitate enabling privacy by obscuring the node’s addresses. This study proposes a protocol for dynamic, auto-configuring and conflict-free IPv6 addressing scheme that attempts to ensure privacy of nodes. In the proposed protocol, each node obtains a three-level hierarchical IPv6 address space which is dynamically generated on basis of congruence classes. Use of congruence classes, along with hierarchical addressing, facilitates generation of inter-leaved (and hence, disjoint) and non-fragmented address space for each node, resulting in conflict free address auto-generation. Nodes auto-configure their address sets independently with congruence seeds shared by routers, potentially reducing router complexity. To ensure the MAC address privacy, MAC address also changes when IPv6 address changes and it is derived from the interface identification (IID) part of the IPv6 address. The proposed protocol runs on Contiki operating system, simulated in Cooja. Simulated results highlight lower latency and optimal communication costs when compared with existing protocols. [ABSTRACT FROM AUTHOR]

This study investigates the performance of user equipments (UEs) and IoT devices in a multi-user (MU) multiple-input single-output (MISO) configuration based non-orthogonal multiple-access (NOMA) system. The proposed model includes a base station surrounded by many users and a number of dispersed IoT devices. In the considered MU IoT network scenario, power allocation coefficients are set to ensure that both the relaying UE and the targeted IoT device experience increased performance. To assist the intended IoT device with weak channel conditions, an optimal user selection method is developed that picks a UE with comparatively better reception, and thereby the selected UE acts as relay forward node utilizing the simultaneous wireless information and power transfer protocol. The characterization of a key performance metric, i.e., the outage probability is derived by adopting a two-step procedure. First, quadratic forms of signal to interference plus noise ratio (SINR) at the relaying UE and the signal-to-noise ratio (SNR) and SINR at the intended IoT device are constructed. Then, using the indefinite quadratic form approach, we arrive at closed-form expressions for the outage probability (OP) of intended IoT device under linearly dependent beamformers. To validate the analytical expressions provided in this study, simulations are performed. We demonstrate that by utilizing the proposed user selection technique in MU-MISO-NOMA system decreases the OP of the intended IoT device by 40% on average. Furthermore, utilizing multiple transmit antenna elements decreases the OP of the intended IoT device by approximately 10%. [ABSTRACT FROM AUTHOR]

Underwater acoustic sensor network (UASN) effectively improves the reliability of underwater long distance transmission through multi-hop transmission between multiple nodes. However, the limited energy of underwater acoustic nodes and large end-to-end transmission delay lead to uneven load and short lifetime of UASN. In this paper, we propose a dynamic layered routing protocol based on back propagation neural network (BP-NN), named as BPDLR, to address the above issues. In the proposed scheme, considering such factors as node topology, residual energy and communication environments, the UASN is vertically divided into the top layer, the middle layer and the bottom layer. The routing designs in each layer are different, and each of them is predicted by BP-NN training model for routing. In addition, we compare the proposed BPDLR protocol with the existing schemes such as static layered routing (SLR) protocol and depth-based routing (DBR) protocol in terms of network node survival, average end-to-end delay and packet loss rate. The simulation results show that, the proposed BPDLR protocol effectively alleviates the energy hole problem of UASN and extends the network lifetime. [ABSTRACT FROM AUTHOR]

• There is no collaborative multihop LoRa protocol. Users 'nodes cannot relay each-other's messages. • MauMe assumes users have a home-node with permanent power supply (base-node) acting as a relay for all users. • MauMe is single channel and designed for a controlled flooding of messages. • Messages are acknowledged. Acknowledgments kill lost messages. • Users can activate local Wi-Fi connection to allow sending free emergency SMS using a smartphone. • MauMe has a ready-to-use Github C++ library which allows immediate deployment on ESP32 microcontrollers. • The proposed implementation respects the legal duty-cycle. Low-cost low-power long-distance LoRa radio devices recently made available on the market allow the emerging of a new generation of networking paradigms on the Internet of Things. While the LoRaWan offers an efficient way of connecting LoRa end-point devices to the internet, LoRaWan nodes do not act as peers, but rather as terminals connected to gateways. As such, the current state of the art does not offer a public protocol for easily taking advantage of the fact that individuals and professionals wishing to aggregate data using LoRa devices are likely to run each a "base-node" on a continuous basis. Such permanently-powered base-nodes could potentially offer an increased cumulated area coverage to other nodes if they would behave as relays. In the present study, an Epidemic Delay Tolerant Network messaging protocol is proposed, which allows multi-hops between peer LoRa relay-nodes through a raw-LoRa controlled-flooding approach. This protocol has been implemented on low-cost LoRa-chip-equipped microcontrollers in the form of an open-source library acting as a network transport-layer. The design analysis concluded that MauMe is better suited for networks with reduced connectivity (≤ 9), and that a 4-connectivity redundant network could allow each user to send several tens of messages several tens of hops away. The proposed approach was tested on three different LoRa network topologies, and the totality of the packets and acknowledgments reached their destination. Furthermore, the network's activity ceased after delivery, confirming the ability of the protocol to return the network to rest after the flooding. The proposed library also offers to users a free emergency-messaging system implemented as an http server embedded in each node and accessible via Wi-fi. End-users can readily use our solution to easily deploy a network of sensors at a much lower cost than when using multiple gateways. The MauMe protocol is a first step towards the creation of collaborative and application-friendly extended-range LoRa-peers networks, and is intended for use in remote regions with scattered housings such as in the islands and atolls of Polynesia. [ABSTRACT FROM AUTHOR]

The use of collaborative applications in which several individuals interact to solve a problem is an important strategy both in educational settings as well as professional environments. Virtual Reality (VR) technology, in particular, has acquired a predominant role in many industries. However, as the level of immersion and realism of the VR experience increases, so does the demand for computational resources, as rendering processes become increasingly intensive and can negatively affect other communication processes that are critical in collaborative environments. In this paper, we present a software framework based on multi-agent systems that enables the separation of rendering processes from internal data management tasks and communication processes between users, which are prevalent in collaborative virtual reality applications. The results of our validation studies show that, compared to other techniques based on protocol or network enhancements, the proposed architecture can significantly improve collaborative processes in general, and virtual reality-based applications in particular. • A multi-agent paradigm is proposed for the development of collaborative VR-based applications. • The multi-agent architecture enables separating data management and communication tasks from rendering tasks. • The proposed paradigm demonstrates significant improvements in terms of computational cost in collaborative applications. • The use of an agent-based architecture enables the scalability of the platform. [ABSTRACT FROM AUTHOR]

With the development of the Internet of Things, multi-access edge computing (MEC) is widely used in industrial IoT, intelligent transport systems, and IoT data management. As a decentralized, tamper-proof, multiparty trusted ledger technology, blockchain can enhance MEC security, privacy, and automatic use of resources. However, highly redundant storage and complex consensus prevent the blockchain from being directly deployed to edge computing nodes with limited resources. Unlike existing lightweight schemes, which do not consider liberating transaction data from blocks, this paper proposes a lightweight blockchain ledger protocol for MEC networks. The novelty of this work is that the transaction data in the block is compressed into a succinct proof through the zero-knowledge proof algorithm. To reduce the storage of block data, this paper proposes the proof-of-state-transfer model in which nodes verify the correctness of the global state transfer in the block without transactions. To reduce the communication complexity of consensus, this paper proposes a lightweight consensus protocol, which reduces the communication complexity of block voting and view switching to O (n). This paper develops the prototype system of TinyLedger to experiment and evaluate the performance of the system in terms of storage, verification, throughput, and communication. Experimental results show that compared to Ethereum, TinyLedger reduces storage capacity by 98.16%, communication volume by 74.53%, and block verification time by 87%. [ABSTRACT FROM AUTHOR]

Real-time simulation is crucial in time-critical situations within the environmental modeling domain. The advancement of web technologies has facilitated the sharing and integration of various resources over the Internet. Web-based real-time modeling has gained increasing attention. However, interoperability remains a challenge when integrating environmental models and real-time observations in a web environment. This paper proposes an interoperable and service-oriented approach for real-time modeling by coupling the Open Geospatial Consortium (OGC) Web Processing Service (WPS) and SensorThings Application Programming Interface (API). The SensorThings API provides a unified way to interconnect environmental sensors, data, and applications. The OGC WPS defines standard operations for accessing online processes. We extended OGC WPS to support the Message Queuing Telemetry Transport (MQTT) protocol and integrated it with SensorThings API. This integration enables real-time access to sensor observations and time-series simulation results. A prototype system using the Storm Water Management Model (SWMM) demonstrates the applicability and effectiveness of our approach. • We proposed an interoperable and web-based approach for integrating IoT real-time observations into environmental models. • OGC WPS and SensorThings API work collaboratively for environmental modeling using the MQTT protocol. • Key issues, including network protocol, data exchange, and execution workflow, are considered to improve interoperability. [ABSTRACT FROM AUTHOR]

Abstract In the classic cake-cutting problem (Steinhaus, 1948), a heterogeneous resource has to be divided among n agents with different valuations in a proportional way —giving each agent a piece with a value of at least 1 ∕ n of the total. In many applications, such as dividing a land-estate or a time-interval, it is also important that the pieces are connected. We propose two additional requirements: resource-monotonicity (RM) and population-monotonicity (PM). When either the cake or the set of agents grows or shrinks and the cake is re-divided using the same rule, the utility of all remaining agents must change in the same direction. Classic cake-cutting protocols are neither RM nor PM. Moreover, we prove that no Pareto-optimal proportional division rule can be either RM or PM. Motivated by this negative result, we search for division rules that are weakly-Pareto-optimal — no other division is strictly better for all agents. We present two such rules. The relative-equitable rule, which assigns the maximum possible relative value equal for all agents, is proportional and PM. The so-called rightmost mark rule, which is an improved version of the Cut and Choose protocol, is proportional and RM for two agents. [ABSTRACT FROM AUTHOR]

Abstract Recently, spectrum optimization solutions require mobile phones to obtain precise, accurate and fine-grained estimates of the radio link data rate. In particular, the effectiveness of anticipatory schemes depends on the granularity of these measurements. In this paper we use a reliable LTE control channel sniffer (OWL) to extensively compare mobile phone measurements against exact LTE radio link data rates. We also provide a detailed study of latencies measured on mobile phones, the sniffer, and a server to which the phone is connected. In this study, we show that mobile phones can accurately (if slightly biased) estimate the physical radio link data rate. We highlight the differences among measurements obtained using different mobile phones, communication technologies and protocols. We also provide detailed instructions on how to replicate our measurements and describe alternative measurement setups and their tradeoffs. [ABSTRACT FROM AUTHOR]

The explosive growth of “things” connected to the Internet (Internet of Things, IoT) raises the question of whether existing ready-to-go networking protocols are enough to cover social and mobile IoT’s demands. IoT aims to interconnect static devices attached to some physical infrastructure. However, mobility is a major factor present in everyday life, and naturally the “things” can move around (Internet of Mobile Things, IoMT) and create social ties (Social IoT, SIoT) in the cyber-physical space. In that context, we present Mobile Matrix ( μ Matrix), a routing protocol that uses hierarchical IPv6 address allocation to perform any-to-any routing and mobility management without changing a node’s address. In this way, device mobility is transparent to the application level favoring IoMT and SIoT implementation and broader adoption. The protocol has low memory footprint, adjustable control message overhead, and it achieves optimal routing path distortion. Moreover, it does not rely on any particular hardware for mobility detection (a key open issue), such as an accelerometer. Instead, it uses a passive mechanism to detect that a device has moved. We present analytic proofs for the computational complexity and efficiency of μ Matrix, as well as an evaluation of the protocol through simulations. We evaluate the protocol performance under human and non-human mobility models. For human mobility, we generated mobility traces using Group Regularity Mobility (GRM) Model, setting its parameters based on real human mobility traces. For the non-human mobility, we propose a new mobility model, to which we refer as Cyclical Random Waypoint (CRWP), where nodes move using a simple Random Waypoint and, eventually, return to their initial position. We compared μ Matrix with three baseline protocols: Routing Protocol for low-power and lossy networks (RPL), Mobility Management RPL (MMRPL), and Ad hoc On-Demand Distance Vector (AODV). The results show that μ Matrix and RPL offer  ≈ 99.9% of bottom-up delivery rate, but only μ Matrix offer  ≥ 95% of top-down traffic in highly dynamic and mobile scenarios, while other protocols  ≤ 75%. Moreover, μ Matrix uses up to 65% of the routing table while RPL and AODV fulfill theirs in all scenarios, which leads to poor top-down and any-to-any reliability. [ABSTRACT FROM AUTHOR]