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Summary: IoT‐assisted WSN contains various nodes, which are placed on a huge scale that increases complications. Thus, the challenges and issues of these networks fluctuate as compared to WSNs. Hence, sensor nodes are imperative unit that runs on less energy resources. Hence, devising a robust and energy‐effective protocol for increasing network lifetime is a complex task. This paper devises a novel hybrid optimization‐driven approach for selecting cluster head (CH) in IoT‐assisted WSNs. Initially, the simulation of IoT nodes is done by configuration. Thereafter, the Cluster Head selection is done using a newly devised optimization technique, namely the Taylor‐Political optimizer (Taylor‐PO). Thus, fitness is newly developed by adapting certain attributes like energy, delay, inter and intra‐cluster distance, Link Lifetime (LLT), predicted energy, and delay. Here, the multipath routing is accomplished using Tunicate Swarm gray wolf optimization (TSGWO). Thus, the proposed Taylor‐PO is offered for effective Cluster Head selection along with multipath routing using TSGWO. The proposed Taylor‐PO offered improved performance with smallest delay of 0.006 sec, highest energy of 2.368 J, highest throughput of 494.043 kbps. [ABSTRACT FROM AUTHOR]

It is well known that control effort is the key factor considered in formation control of a multi‐agent system (MAS). To reduce the controller effort, an economic event‐triggered super twisting control (STC) protocol for the formation tracking of a nonlinear MAS, which avoids the unnecessary computations and transmission of control inputs among agents. Specifically, a distributed leader‐follower control framework, combing the multi‐input STC with event‐triggered strategy, is proposed to ensure that the followers' states reach an agreement on the leaders state. Then, the sufficient conditions for the selection of controller parameters are formulated in terms of linear matrix inequalities (LMIs). On this basis, the event‐triggered conditions for implementing the STC protocol in the network environment are obtained using Lyapunov stability theory. Simulation study is carried out to demonstrate the effectiveness and merits of the STC in terms of formation construction, trajectory tracking, and robustness to system uncertainties. [ABSTRACT FROM AUTHOR]

Vehicle‐to‐grid (V2G) network has a clear advantage in terms of economic advantages, it has attracted the interest of electric vehicle (EV) and power grid users. However, numerous security concerns limit its further progress. In existing V2G protocols a trusted third party independently generates the master key of the system, so if the adversary compromises the third party, then the system may become vulnerable to system master key leakage attack. Recently, Su et al. presented a privacy‐preserving mutual authentication protocol for V2G networks. Firstly, we crypt‐analysis Su et al.'s protocol and show that their protocol is vulnerable to several security attacks such as the reveal of the master secret key, impersonation attacks and the incorrect notion of EV's anonymity and traceability and does not meet the security features they claimed in their paper. Secondly, we verify that Su et al.'s protocol is unsafe against impersonation attacks, system key leakage, and electrical vehicle anonymity attack using the AVISPA tool. [ABSTRACT FROM AUTHOR]

The user datagram protocol is the most widely used protocol for streaming multimedia data over the Internet. Like other protocols at the network and transport layers, it uses the Internet Checksum (IC) to detect channel errors. The consequence of this is that each corrupted packet is dropped, which can degrade the quality of service perceived by a user. In this paper, the authors present a solution to this problem based on integer codes capable of correcting single and double adjacent errors. The presented codes are a generalization of the IC, which makes them easy to implement in software. [ABSTRACT FROM AUTHOR]

A new series of transparent aerogels of biopolymer‐polysiloxane double networks is reported. Biopolymer aerogels have attracted much attention from green and sustainable aspects but suffered from strong hydrophilicity and difficulty to make homogeneous structures in nanoscale; these drawbacks are overcome by compositing with a polysiloxane network. Alginate‐polymethylsilsesquioxane aerogel has high optical transparency, water repellency, comparable superinsulation property and improved bending flexibility compared to pure polymethylsilsesquioxane aerogel. The nanoscale homogeneity is realized by separating the crosslinking steps for two networks in a sequential protocol: condensation of siloxane bonds and metal‐crosslinking of biopolymer. The crosslinking order, biopolymer‐first or siloxane‐first, and universality/limitation of biopolymer‐crosslinker pairs are discussed to construct fundamental chemistry of double network systems for their further application potentials. [ABSTRACT FROM AUTHOR]

A new series of transparent aerogels of biopolymer‐polysiloxane double networks is reported. Biopolymer aerogels have attracted much attention from green and sustainable aspects but suffered from strong hydrophilicity and difficulty to make homogeneous structures in nanoscale; these drawbacks are overcome by compositing with a polysiloxane network. Alginate‐polymethylsilsesquioxane aerogel has high optical transparency, water repellency, comparable superinsulation property and improved bending flexibility compared to pure polymethylsilsesquioxane aerogel. The nanoscale homogeneity is realized by separating the crosslinking steps for two networks in a sequential protocol: condensation of siloxane bonds and metal‐crosslinking of biopolymer. The crosslinking order, biopolymer‐first or siloxane‐first, and universality/limitation of biopolymer‐crosslinker pairs are discussed to construct fundamental chemistry of double network systems for their further application potentials. [ABSTRACT FROM AUTHOR]

Summary: Human‐centered Internet of things (IoT) systems enable human beings to enjoy the ubiquitous services and play more and more important roles in our life. A common application scenario in human‐centered IoT systems is that two distributed wireless devices from heterogeneous networks want to communicate with each other. However, key generation centers (KGCs) from different networks usually use independent security parameters. It is difficult for two users with different security parameters to establish a common session key. We propose a certificateless key exchange protocol for two different devices managed by different KGCs to address the issue. The security of the proposed protocol is conducted in the random oracle model with the hardness assumption of elliptic curve computational Diffie‐Hellman (ECDH) problem. The main merits of our protocol include the following: (a) it enables users from heterogeneous networks to establish upon a shared session key, (b) it can solve the key escrow problem, (c) it does not use bilinear pairings and obtains computational efficiency, and (d) it achieves stronger security compared with other related protocols. [ABSTRACT FROM AUTHOR]

Summary: The Internet of Things (IoT) continues to expand the current Internet, opening the door to a wide range of novel applications. The increasing volume of the IoT requires effective strategies to overcome its challenges. Machine Learning (ML) has led to a growing technology that enables computers to solve problems without the need for knowledge of their intricate details. Over the past years, various ML techniques have been used to efficiently manage IoT networks. Clustering is a technique that has proven its performance in the networking domain. Many works in the literature have studied ML‐based clustering methods for IoT networks, including their main properties, characteristics, underlying technologies, and open issues. In this paper, we focus on topology‐centered ML‐based clustering protocols for IoT networks. Specifically, we investigate the potential benefits of adopting the clustering approach to address several IoT challenges. Moreover, we provide a comprehensive taxonomy of ML‐based clustering algorithms for IoT networks. Finally, we statistically analyze the incorporation of ML techniques for clustering in various IoT systems and highlight the related open issues. [ABSTRACT FROM AUTHOR]

Today, Internet of things (IoT), Cloud and Fog networks have spread out around the world. The more these networks grow, the more their energy consumption comes to attention. Many efforts have been made during recent years to decrease this energy consumption, mainly focused on utilizing low‐power devices. Green algorithms are recently proposed to reduce energy consumption by modifying the structure of many algorithms employed in the network and its protocols. This paper proposes a new green reliability algorithm for Transmission Control Protocol/Internet Protocol (TCP/IP protocol) in Fog computing. The proposed algorithm does not require extensive TCP/IP protocol changes or relevant hardware. It is based on transferring less number of packets in the network by using the advantage of differences between TCP and User Datagram Protocol (UDP). TCP and User Datagram Protocol (UDP) are different in nature as the number of total packets in UDP is half that of TCP. As a result, the number of complete packets in UDP is half that of TCP. The proposed method is built around the loss of some packets in applications, such as voice and online video, does not severely degrade the end results. Therefore, the UDP protocol can substitute TCP in such situations. The criterion to switch between the two is the minimum acceptable Quality of Service (QoS) of the overall network. In other words, the UDP protocol will be used as long as QoS requirements are met. The switching process between UDP and TCP is dynamic, optimized by estimating network noise in the period. Additionally, we evaluated the proposed method based on several QoS functions, including delay, throughput, and energy usage. [ABSTRACT FROM AUTHOR]

Summary: Recently, much of the wireless personal area network (WPAN) research concerns network protocols, scheduling, and security challenges but the major issue of resource utilization has been very rarely investigated. The design of resource sharing in a network gets more attention when the number of users increases. While optimizing performance, resource utilization plays a critical role. In this paper, the numerical performance of a wireless resource utilization algorithm for a bi‐partite scatternet is presented. This algorithm is focused to enhance the bandwidth allocation and power utilization of wireless scatternets. Every node can communicate with a single neighbor at a time with minimum resources. Finally, the performances of the RUBI algorithm are shown. This algorithm is compared with the existing algorithms such as the load adaptive scheduling algorithm and pseudorandom coordinated scheduling scheme in terms of various parametric metrics like reliability, throughput, collision probability, transmission probability, and signal‐to‐noise ratio (SINR). The proposed L‐RUBI achieves 93.4% of reliability, 93.6% of transmission probability, 91.4% of throughput, 76.8% of collision performance, and 72.2% SINR. [ABSTRACT FROM AUTHOR]

Summary: A well‐optimized and well‐performed communication network protocol is necessary to build successful underwater acoustic sensor networks (UWASNs). But for wired and wireless communication, medium access control (MAC) has a great effect on network performance and optimization. But unlike land‐based MAC protocols, underwater MAC protocols come with various challenges and issues like high propagation delay, limited bandwidth for communication signals, large attenuation in network signals, and the high noise level in signals. It is very challenging to build a well‐optimized underwater MAC protocol. Also, in UWASN, sensor nodes are generally divided into sub‐network parts to reduce the propagation delay of data signals. But this creates the problem of non‐uniform traffic load in sensor nodes. So, considering these issues, dynamic hold time MAC (DHT‐MAC) protocol is proposed here. In this protocol, depending on the distance from the central node, sensor nodes are divided into two sub‐network zones (parent node and child node). Depending on the traffic load and propagation delay, the child nodes can change their respective parent nodes dynamically. Advantage of the proposed method is that, if any of the parent nodes stops working, the child node will connect to the nearest parent node. When collecting the data signals, it has been observed that child nodes have a light traffic load compared to parent nodes. So dynamic cooperative transmission MAC (DCT‐MAC) protocol which is a contention‐based MAC protocol has been used in child nodes and as parent nodes have high traffic load, reservation‐based MAC protocol has been used. [ABSTRACT FROM AUTHOR]

Summary: Vehicular ad hoc networks (VANETs) are receiving increased attention, and several routing protocols have been proposed already by the research community. In such a framework, social aspects and human mobility are important performance enablers, which however are mostly overlooked. In this work, we propose the socially aware CLWPR (SCALE) protocol, significantly enhancing cross‐layer weighted position‐based routing (CLWPR), a routing protocol for urban VANET environments, combining social properties such as trust, influence, and users' individual mobility patterns to its core design in order to support an efficient content dissemination scheme. The design principles of SCALE that rely on both online and offline social metrics quantifying relationships on social networking platforms and opportunistic contacts of nodes due to physical proximity, respectively, are presented, while nodes with close online and offline social relationship are favored as next forwarder nodes. Subsequently we provide the performance evaluation of SCALE against other routing protocols in distributed vehicular networks, employing representative urban scenarios with synthetic and real traffic. It is shown that the proposed approach presents improved performance in terms of Packet Delivery Ratio (PDR) and throughput when compared with other similar protocols by an average of 37% in scenarios with synthetic dataset and 58% with real dataset for PDR and by an average of 45% in scenarios with synthetic dataset and 61% with real dataset for throughput. [ABSTRACT FROM AUTHOR]

Summary: Wireless sensor network (WSN) is frequently being used for increasing the data collection and monitoring critical parameters. Major challenge in WSN design is achieving the better energy efficiency and latency considering the dynamic sink location. Lots of research has been done for improving the performance of WSN systems in wide range of applications. Prime goal of this paper is to evaluate the performance of WSN routing under the grid‐based dynamic sink locations. Later the performance of various existing critical protocols is compared to route data over centralized server. Various applications of WSNs are tabulated along with the sensor utilization. The paper contributed in three passes. Initial contribution of this research is to identify the issues and limitations of present WSN communication technologies. The paper contributed to present a case study to discover the implications of dynamic sink routing for building protocol to extend network's lifetime. The effectiveness of several clustering‐based WSN routing algorithms is first compared in this paper. After that, the protocol with the longest network life is put to the test under a grid‐based dynamic sink routing scenario. The significance of clustering‐based protocols for improving lifetime of the network is evaluated as case study. The clustering‐based energy efficient protocol like low energy adaptive clustering hierarchy (LEACH) and its different variants, PEGASIS, SEP, DEC, their variants, and so on, are compared in this paper. Various performance metrics like network delays, throughput, latency, energy consumption and network lifetime are defined for studying routing protocols. Significance of dynamic sink locations performance is evaluated for Enhanced Distributed Energy Efficient Clustering (EDEEC) protocol. Overall paper covers and reviewed many critical design aspects for WSN networks. [ABSTRACT FROM AUTHOR]

Summary: The vast number of smart cloud applications that communicate with the "things" over a variety of physical networks and communication protocols contribute to the rise of complexity in Internet of Things (IoT) systems. The diversity of end‐user requirements related to the volume of generated data, its variety, and the velocity of its transmission makes quality of service (QoS) provisioning even more crucial and challenging in IoT. This paper provides a comprehensive and up‐to‐date survey of QoS support in IoT networks and communication protocols. An analysis of the QoS‐aware IoT architectures, layer‐dependent QoS metrics, and network resource optimization methods utilized in IoT systems are given. The limitations of the current state‐of‐the‐art studies for efficient delivery of QoS metrics are discussed. The paper concludes with future research directions on end‐to‐end QoS provisioning in IoT. [ABSTRACT FROM AUTHOR]

Classifying test executions automatically as pass or fail remains a key challenge in software testing and is referred to as the test oracle problem. It is being attempted to solve this problem with supervised learning over test execution traces. A programme is instrumented to gather execution traces as sequences of method invocations. A small fraction of the programme's execution traces is labelled with pass or fail verdicts. Execution traces are then embedded as fixed length vectors and a neural network (NN) component that uses the line‐by‐line information to classify traces as pass or fail is designed. The classification accuracy of this approach is evaluated using subject programs from different application domains—1. Module from Ethereum Blockchain, 2. Module from PyTorch deep learning framework, 3. Microsoft SEAL encryption library components, 4. Sed stream editor, 5. Nine network protocols from Linux packet identifier, L7‐Filter and 6. Utilities library, commons‐lang for Java. For all subject programs, it was found that test execution classification had high precision, recall and specificity, averaging to 93%, 94% and 96%, respectively, while only training with an average 14% of the total traces. Experiments show that the proposed NN‐based approach is promising in classifying test executions from different application domains. [ABSTRACT FROM AUTHOR]

Summary: The development of tiny sensor nodes (SNs) has incarnated numerous applications in the field of wireless sensor networks (WSN). These devices became much popular in multidisciplinary research area such as the internet of things (IoT). However, the use of these devices has been restricted due to some constraints like SN energy, data aggregation, quality of service (QoS), reliability, SN deployment, scalability, energy consumption, and many more. Among all these constraints, we focus on SN energy, SN deployment, and energy consumption of the network. Because if the consumption of SN energy is less, network lifetime automatically increases. So, we propose active–passive node topology on deployed SNs which enhance the network lifetime. With the help of the proposed mechanism, the lifetime and stability have increased by 60% and 3%, respectively, as compared with directed diffusion protocol in Experiment 1. In another experiment, the lifetime has increased by 67%, 64%, and 62% as compared with LEACH, NEAP, and DREEP, respectively, in homogeneous environment. The proposed scheme also performed significant improvement in heterogeneous environment. The simulation performance shows that the proposed protocol increases the network lifetime and stability of the network. [ABSTRACT FROM AUTHOR]

Summary: With the improvement of industrial informatization, various industrial control system network protocols have also been widely used. The reliability of these protocols will directly affect the safety of industrial control systems. As an effective method that can automatically analyze system reliability, model checking has been widely used in the verification of various safety‐critical systems. In this paper, we propose a modeling design method for industrial control network protocol based on time semantic reconstruction of time state transition matrix (TSTM). In addition, we provide a TSTM model checking method based on linear temporal logic (LTL). In order to effectively alleviate the state space explosion, the method adopts bounded model checking (BMC) technology. Furthermore, we implement a TSTM model verification tool called ICPV. Finally, we apply the above method to the modeling and verification of the industrial control network protocol Powerlink and through a comparison experiment with UPPAAL to illustrate the effectiveness of the method proposed in this paper. [ABSTRACT FROM AUTHOR]

Publishing systematic review protocols is a fundamental part of systematic reviews to ensure transparency and reproducibility. In this scoping review, we aimed to evaluate reporting of Cochrane systematic review protocols with network meta‐analyses (NMA). We searched all Cochrane NMA protocols published in 2018 and 2019, and assessed the characteristics and reporting of methodologies relevant to NMA. We reported frequencies for each reporting item. Forty‐five protocols were assessed, including two for overviews and 43 for intervention reviews. Thirty‐three (73%) were labelled as NMA protocols in the title. Forty‐two (95%) justified the need of an NMA and 40 (89%) used appropriate search strategies to identify potential eligible studies. About half (24, 53%) considered the transitivity assumption when reporting inclusion criteria and 35 (78%) specified potential effect modifiers. Forty‐three (96%) reported statistical software for NMA, 25 (56%) reported NMA model choice, 32 (71%) reported framework choice and 32 (71%) reported assumption about heterogeneity variances. Protocols varied in whether they reported methods for relative ranking (35, 78%), statistical inconsistency (40, 89%), reporting bias (44, 98%) and sources of heterogeneity (39, 87%). In conclusion, Cochrane NMA protocols reported multiple NMA‐specific items well, but could be further improved, especially regarding transitivity assumptions. Our recommendations for NMA protocol reporting based on this scoping review could assist authors, reviewers, and editors to improve NMA protocols. [ABSTRACT FROM AUTHOR]

Summary: The handoff process in WiFi networks has a very important role to provide continuity of the service to wireless users where the access points (APs) are in numerous numbers. In traditional WiFi networks, the handoff process takes a few seconds and is initiated by the wireless devices, but these few seconds could be a reason for information loss when dealing with delay sensitive applications. In this paper, we propose a reduced detection and discovery time approach (DeRy), which generates a solution based on software defined WiFi networks (SD‐WiFi). A simple network management protocol (SNMP) manager and received signal strength indicator (RSSI) manager are employed to report the AP traffic conditions and RSSI values to the SDN controller and instead of the wireless devices, the handoff decisions are taken at the controller end. When to initiate the handoff (detection phase) and which destination AP to associate to (discovery phase) are handled by the centralized SDN controller. To implement DeRy, extensive simulation runs are carried out on Mininet‐NS3‐WiFi network simulator. The simulation results show that the DeRy significantly reduces the handoff times by 60–70% and reduces the average number of retransmission by 4–49%, hence maintaining the throughput for delay sensitive applications such as VoIP, when compared to the standard RSSI‐based handoff scheme, channel measurement based access selection scheme (CMAS) and (DL‐SINR) downlink‐signal to interference plus noise ratio AP selection scheme (DASA). [ABSTRACT FROM AUTHOR]

In the networks, a transport layer is responsible for reliable data with guaranteed Quality of Service. A Modified‐QUIC protocol provides improved throughput and reduced latency of the network. This work proposes a modification in handshaking mechanism for QUIC protocol to minimize overhead due to control signals and time required to update the congestion‐window size. This modification fine‐tunes the window update mechanism with the acknowledgment frame, which results in a smooth variation in the congestion‐window size. This leads to the control congestion by regulating traffic in the network. In the proposed mechanism, unnecessary time out events are avoided by updating the congestion‐window on receipt of the acknowledgment frame. This work has been carried out using two different testbed setups to verify the transport layer and a browser network performance. It has been observed that a Modified‐QUIC protocol is easy to deploy, improves the throughput and data rate by 35% and 3.43%, respectively, over the QUIC protocol. The average fairness index is increased with a file size and for the long live traffic. [ABSTRACT FROM AUTHOR]

This paper considers a full duplex (FD) cooperative non‐orthogonal multiple access system that employs power splitting relaying (PSR)‐based simultaneous wireless information and power transfer (SWIPT) technique, that is, FD‐PSR‐NOMA system. A single cell network is considered consisting of a base station (BS) and two pre‐paired users, where the near user is configured to act as FD relay to assist the BS for information delivery to the far user. It is assumed that the far user implements maximal ratio combining to combine the direct link signal arriving from the BS and the relayed signal from the near user, to exploit the diversity advantage. Analytical expressions are derived for the outage probabilities of the downlink users, system outage probability, and the throughput of the considered network under imperfect successive interference cancellation (i‐SIC). Analytical expressions are also derived for the outage probabilities and throughput of half duplex (HD) cooperative NOMA system under PSR‐based SWIPT, that is, HD‐PSR‐NOMA system. Further, the asymptotic outage probabilities and diversity orders are derived as well. The optimal power allocation factors at the BS that minimize the system outage probabilities of FD/HD‐PSR‐NOMA networks are determined. Extensive simulation results are provided to corroborate the analytical findings. [ABSTRACT FROM AUTHOR]

The load flow analysis project was carried out using the Newton‐Raphson's iteration technique and a multiobjective method was suggested to minimize power loss, increase bus voltage, reduce operating costs, and controlling the flexible AC transmission system (FACTS) controllers. The key focus is to improvise the load sustainability subjected to controlling of system safety, integrity, and stability margins within specified limits by acquiring optimum place, installation expenses for FACTS controllers. It is important to analyze the benefits and architect the FACTS devices for the power steady state analysis. For effective modeling, the five bus standard is analyzed without the FACTS end devices and with the FACTS controllers. Transient voltage is critical which requires accurate and quick response to avoid the voltage collapse and instability issues. The Newton‐Raphson's method of load flow analysis is an iterative method which approximates the set of nonlinear simultaneous load flow equations to a set of linear simultaneous load flow equations using Taylor's series expansion and the terms are limited to first order approximation. The variations in voltage are within 5% for a well designated power system. If it exceeds the specified limit then the performance of equipment will be poor and the life of equipment will reduce. Hence the voltage control is very important to improvise the quality factor of the FACTS controllers and devices in power system. The voltage variations in a bus or node are related to reactive power. If the reactive power is injected to a bus is less than reactive power drawn from the FACTS devices, the voltage instability becomes infinite issue causes damage to the controllers and devices. In a load flow problem, two quantities are specified for each bus and the remaining quantities are obtained by the load flow equation analysis using Newton‐Raphson method. This method has been tested for IEEE 30 bus system and then the values are compared and analyzed with MATLAB. [ABSTRACT FROM AUTHOR]

Summary: To design a reliable and energy efficient medium access control (MAC) protocol for underwater wireless sensor networks (UWSNs) is an active research area due to its variety of applications. There are many issues associated with underwater acoustic channels including long and variable propagation delay, attenuation, and limited bandwidth which pose significant challenges in the design of MAC protocol. The available sender‐initiated asynchronous preamble‐based MAC protocols for UWSNs are not reliable and energy‐efficient. This is due to the problems caused by transmission of preambles for longer duration and collision of preambles from hidden nodes in sender‐initiated preamble‐based MAC protocols. To resolve these issues, the paper proposed an asynchronous receiver‐initiated preamble‐based MAC protocol named Receiver Preambling with Channel Polling MAC (RPCP‐MAC) protocol for shallow underwater monitoring applications with high data rates. The protocol is proposed to resolve data packet collision and support reliability in an energy‐efficient way without using any transmission schedule. The proposed protocol is based on the following mechanisms. Firstly, receiver preambling mechanism is adopted to reduce idle listening. Secondly, channel polling mechanism is used to determine missing data frame during its sleeping period and to minimize the active time of node and reduces energy wastage. Finally, a back‐off mechanism is applied to resolve collision when preambles are received simultaneously. In addition, performance analysis through Markov chain together with its validation with simulation‐based studies is reported in the paper. Both the analytical and simulation results have demonstrated the reliability achievable with RPCP‐MAC while providing good energy efficiency. [ABSTRACT FROM AUTHOR]

Summary: Covert channels have been recently the subject of the study in both creation and countermeasure aspects. There are many different ways to embed the covert data in network standards and protocols, especially in wireless networks. MORE (MAC‐independent opportunistic routing) is an opportunistic routing protocol which uses networks coding to enhance routing performance by reducing the repetitions. This protocol can be a suitable medium for covert channel establishment. A middleman covert channel establishment method is proposed in this paper over MORE routing protocol and with the use of network coding. Hidden data are transferred through packet's payload bytes. Covert sender manipulates coding mechanism by calculating packets' coefficients instead of random selection. The proposed covert channel provides the average throughput of 218 and 231 bps, using two different data length approaches which is relatively a good comparing to the previous network layer covert channels. The proposed covert channel is also a covert storage channel and cannot be removed or restricted. Effect of different network characteristics on the proposed method's capacity and security is investigated by a simulation study, and the results are discussed. [ABSTRACT FROM AUTHOR]

Achieving reliable and energy-saving broadcast is the main issue discussed in this study. Firstly, a multi-hop broadcast model is introduced, and the energy consumption and reliability of the network are defined in this study. Then five broadcast-based automatic repeat request (ARQ) protocols (automatic retransmission N times, stop-and-wait end-to-end-ARQ, stop-and-wait hop-by-hop-ARQ, stop-and-wait hop-by-hop oriented implicit ARQ, stop-and-wait hop-by-hop implicit and explicit ARQ) are proposed to realise the reliable transmission. Secondly, based on five protocols, the relationship between the system reliability and the number of retransmissions of the root node is established analytically, and the maximum number of retransmissions is solved under the required system reliability. Thirdly, the energy consumptions of the root node are calculated, and then the analytical expressions of the minimum system energy consumption are obtained separately according to five broadcast-based retransmission mechanisms. Finally, the relationships between the maximum number of retransmissions, energy consumption and reliability, the broadcast probability and feedback probability are discussed in the numerical analysis. Specially, for better energy-saving, the modulation technique should be adopted to choose suitable protocol based on a dynamic hop threshold. [ABSTRACT FROM AUTHOR]

Laboratory sources for standard frequency and time that receive external time signals to control their built‐in oscillators are widely used wherever accurate and stable frequency and time, optionally with universal synchronization, are required. We propose a method to obtain traceability of such signals to Coordinated Universal Time (UTC) and particularly to UTC(PTB), its realization by the Physikalisch‐Technische Bundesanstalt (PTB). The role of PTB's weekly published Time Service Bulletin is discussed in detail, and the metrological steps for establishing and maintaining traceability are described and uncertainty contributions are stated. Furthermore, we discuss how to possibly meet financial sector regulations according to European MiFID II. A procedure as a component for the assessment to provide accurate time through telecommunication networks using, eg, the Network Time Protocol (NTP) is presented. It checks outputs of an NTP server to validate that its time reference and provided time‐of‐day information is in accordance with specific requirements. [ABSTRACT FROM AUTHOR]

Compared with traditional radio frequency identification (RFID), computational RFID (CRFID) tag has more powerful computing capability, but it shows poor performance when it follows EPC Class-1 Generation-2 protocol especially transmitting large amounts of data. In fact, the operation of the CRFID tag entirely depends on the state of energy. For this point, this study proposes an optimised protocol called LILAC. LILAC allows tags to select the communication time slot according to their current voltage value measured by using an analogue-to-digital converter rather than randomly selecting, the authors proposed a more reasonable time slot mapping algorithm for LILAC that increases the success rate of tag responding. In addition, they design a data transmission format that can be retransmitted to improve the uplink throughput. Finally, they implemented LILAC on a CRFID platform and practically measured several parameters to compare with the existing well-known protocol. The results of experiments show that LILAC increases the maximum communication distance by more than half in the access phase and doubles the goodput of the backscatter link in both the inventory and access phase. [ABSTRACT FROM AUTHOR]

To accommodate the proliferation of heterogeneous network models and protocols, the use of semantic technologies to enable an abstract treatment of networks is proposed. Network adapters are employed to lift network specific data into a semantic representation. Semantic reasoning integrates the disparate network models and protocols into a common data model by making intelligent inferences from low‐level network and device details. Automatic discovery of new devices, monitoring of device state, and invocation of device actions in a generic fashion that is agnostic of network types is enabled. A prototype system called SNoMAC is described that employs the proposed approach operating over UPnP, TR‐069, and heterogeneous sensors. These sensors are integrated by means of a sensor middleware named SIXTH that augments the capabilities of SNoMAC to allow for intelligent management and configuration of a wide variety of sensor devices. A major benefit of this approach is that the addition of new models, protocols, or sensor types merely involves the development of a new network adapter based on an ontology. Additionally, the semantic representation of the network and associated data allows for a variety of client interfaces to facilitate human input to the management and monitoring of the system. [ABSTRACT FROM AUTHOR]

Wireless body area networks (WBANs) can be widely used in wireless medical, motion detection etc. However, the existence of interference results in the increase in energy consumption and delay. To mitigate interference, nodes are prevented from using the same or similar spectrum resources by adopting multi-channel media access control (MAC) protocols. Here, the authors propose a multi-channel MAC protocol towards energy efficiency and low interference (EIMAC). Firstly, the states of each channel are clarified by the channel mapping mechanism. A novel channel selection strategy, considering the unfairness between high or low priorities, then is carried out. After that, considering the characteristics of node including residual energy, user priority, and data volume, the authors propose a low energy consumption enabled transmission mechanism. Lastly, the authors utilise a novel collision avoidance mechanism to reduce the collision probability of packets. Numerical results show that EIMAC significantly enhance the performance of WBANs in terms of delay, throughput, and energy consumption. [ABSTRACT FROM AUTHOR]

The rapid urbanisation has transformed cities to the preferential human settlement and allowed cities to quietly witness all range of human activities. As the key enabler in the information and communications technology industry, cellular networks play a decisive role in delivering communication messages and entertainment content. In particular, cellular network operators respond to human initiated service requests by gradually deploying necessary infrastructure and calibrating transmission protocols. Hence, cellular network records encompass the interesting interaction between human-initiated messages and network-triggered responses. In this study, the authors collect the 'big data' in urban cellular networks and try to dig out the human and urban planning properties. Specifically, they focus on the statistical modelling of three representative scenarios like spatial deployment density of base stations, packet length or traffic volume of mobile services, as well as inter-arrival time and dwell time of human mobility. Through extensive data mining, they validate the heavy-tailed feature universally existing in these scenarios. Afterwards, they discuss the implications of this heavy-tailed feature and talk about its fundamental contribution to intelligent resource adjustment, proactive content caching, and enhanced connection management in cellular networks. Finally, they highlight the applications of this feature towards smarter cellular networks and cities. [ABSTRACT FROM AUTHOR]

Recently, Chaudhry et al and Kumari et al proposed an advanced mutual authentication protocol for Session Initiation Protocol on the basis of the protocol of Lu et al. The authors claimed that their schemes can be resistant to various attacks. Unfortunately, we observe some important flaws in their respective schemes. We point out that their schemes are prone to off-line password guessing and privileged insider attacks. To remedy their protocols's drawbacks, in this paper, we present a new improved authentication scheme keeping apart the threats encountered in the design of the schemes of Chaudhry et al and Kumari et al. Furthermore, the security analysis illustrates that our proposed scheme not only removes these drawbacks in their schemes but also can resist all known attacks and provide session key security. We give a heuristic security analysis and also provide the security analysis of the proposed scheme with the help of widespread Burrows-Abadi-Needham Logic. Finally, our scheme is compared with the previously proposed schemes on security and performance. [ABSTRACT FROM AUTHOR]

This paper presents the modeling and analysis of a proposed label-quality of service (QoS) switching protocol for heterogeneous robot in a swarm. Establishing the data communication and network in multirobot task allocation is an important aspect in robot collaboration. Instead of passing the data through the cloud network, each robot can be configured as a node in its swarm for intercommunication. This research was conducted to model and propose aggregation and classification methods in a swarm robot network inspired from multiprotocol label switching, namely, label-QoS switching protocol. Each packet of data is forwarded with a proposed 2-side label values that are concerned with addressing and QoS. This proposed protocol was applied in each of the node's routing, and it was set up with forwarding information table. The simulation and analysis were conducted in 2 situations: (1) with a constant n-label switch mobile robot and a number of packet data increasing with time and (2) with a constant number of packet and varying n-label switch mobile robot by time. With reference to the network parameter performances, it shows that the anomaly treatment by the proposed protocol is able to prioritize the data forwarding between the robots at the edge of the swarm with class of service although the robot community at the center is increasing or getting crowded. [ABSTRACT FROM AUTHOR]

Overlapping is one of the topics in wireless sensor networks that is considered by researchers in the last decades. An appropriate overlapping management system can prolong network lifetime and decrease network recovery time. This paper proposes an intelligent and knowledge-based overlapping clustering protocol for wireless sensor networks, called IKOCP. This protocol uses some of the intelligent and knowledge-based systems to construct a robust overlapping strategy for sensor networks. The overall network is partitioned to several regions by a proposed multicriteria decision-making controller to monitor both small-scale and large-scale areas. Each region is managed by a sink, where the whole network is managed by a base station. The sensor nodes are categorized by various clusters using the low-energy adaptive clustering hierarchy (LEACH)-improved protocol in a way that the value of p is defined by a proposed support vector machine--based mechanism. A proposed fuzzy system determines that noncluster heads associate with several clusters in order to manage overlapping conditions over the network. Cluster heads are changed into clusters in a period by a suggested utility function. Since network lifetime should be prolonged and network traffic should be alleviated, a data aggregation mechanism is proposed to transmit only crucial data packets from cluster heads to sinks. Cluster heads apply a weighted criteria matrix to perform an inner-cluster routing for transmitting data packets to sinks. Simulation results demonstrate that the proposed protocol surpasses the existing methods in terms of the number of alive nodes, network lifetime, average time to recover, dead time of first node, and dead time of last node. [ABSTRACT FROM AUTHOR]

In vehicle-to-vehicle (V2V) communications, achieving reliable physical layer performance is a challenging task due to the highly dynamic nature of V2V propagation channels. Frame timing estimation, as one of the most critical signal processing procedures that rely on channel statistics, has to be appropriately enhanced to tackle this challenge. This study presents a novel frame timing estimation scheme based on both the available periodical preambles in IEEE 802.11p standard. By designing the fourth-order statistics-based correlation and differential normalisation functions, the proposed timing metric not only is capable of possessing an extensible correlation length, but also achieves the robustness to multipath effect and large carrier frequency offset. From the standpoints of hypothesis testing and classification, the proposed approach can effectively increase the distinction between correct and wrong timing indexes in terms of the class-separability criteria, and consequently has a significantly improved timing estimation performance compared with the existing methods. Simulation results consist with theoretical analysis under the typical V2V channel model, and demonstrate that the proposed method can significantly reduce both the probabilities of false alarm and missed detection, and make the selection of a suitable threshold for frame detection much easier. [ABSTRACT FROM AUTHOR]

Summary: To provide privacy protection in mobile health care system, medical users typically encrypt their personal health information before publishing it to the health care center. And other medical users download, decrypt, and process it using an access control protocol. However, current access control protocols are mainly focusing the privacy of personal health information and lacking the protection for medical users' real identities, leading to a variety of security issues. At the same time, current access control protocols for mobile health care systems are usually based on bilinear map, resulting in high computation costs. Observing the above issues, we introduce a novel access control protocol with privacy‐preserving called Access Control for Mobile Healthcare System (ACMHS). Similar to protocols of this field, ACMHS can provide privacy protection for mobile health care systems. However, different from other well‐known approaches, ACMHS uses pseudonyms instead of real identities, which can provide privacy protection for medical users' real identities. Moreover, to reduce the computation cost of bilinear map, we introduce the algebraic signature to ACMHS and design a novel access control protocol, which is much more efficient than current bilinear‐map‐based protocols. By doing so, ACMHS can achieve high efficiency while still enjoying required security requirements. Experimental results show that ACMHS is feasible for real‐world applications. [ABSTRACT FROM AUTHOR]

Summary: Communication protocols in vehicular sensor networks (VSNs) in urban areas play an important role in intelligent transport systems applications. Many cross‐layer communication protocol studies are originated from topology‐based algorithms, which is not suitable for the frequently changing computational scenario. In addition, the influence factors that have been considered for VSNs routing are not enough. With these aspects in mind, this paper proposes a multifactor cross‐layer position‐based routing protocol for VSNs to improve reliability and efficiency in message delivery. Considering the complex intersection environment, the algorithm for vehicles selection at intersections (called AVSI) is further proposed, in which comprehensive factors are taken into account including the position and direction of vehicle, the vehicle density, the signal‐to‐noise‐plus‐interference ratio, and the frame error rate in MAC layer. Meanwhile, the dynamic HELLO_STREAM broadcasting system with the various vehicle speeds is proposed to increase the decisions accuracy. Experimental results in network simulator 3 show the advantage of multifactor cross‐layer position‐based routing protocol over traditional state‐of‐the‐art algorithms in terms of packet delivery ratio, overhead, and the mean end‐to‐end delay. [ABSTRACT FROM AUTHOR]

Summary: Opportunistic networks (OppNets) are networks that can be used in situations of sparse network connectivity. Strategies for implementing secure transmission of messages in OppNets offer complex and distinctive problems that are wholly different from traditional networks using TCP/IP protocols for data transmission. In this paper, a security protocol named FuzzyPT is proposed which combats black hole attacks in OppNets. The defense mechanism is based on the information extracted from messages in the buffer, potential threat (PT) messages, and fuzzy logic. Fuzziness aids the system in being adaptive by modeling the character of nodes as either benign or malicious. It provides the network with the ability to judge the character of nodes based on relationships between different parameters instead of basing this decision on fixed conditions. FuzzyPT is observed to reduce erroneous decision‐making and decrease the number of false positives and false negatives in the system. An evolutionary game theoretic model is applied, which analyzes the decision‐making ability of relays in choosing varied strategies while forwarding messages. The evolutionary stable state is computed for the protocol, which verifies the proposition that a majority of the relays will cooperate by forwarding messages. The efficiency of the protocol is judged on various grounds such as delivery probability, network overhead ratio, packets dropped, and transmission latency. It is observed that the proposed game theoretic protocol outperforms an existing acknowledge and evolutionary game theory–based security protocol in terms of all the aforementioned performance characteristics. [ABSTRACT FROM AUTHOR]

Key exchange protocols play an important role in securing the network communication over an insecure channel. In literature, a large number of key exchange schemes exist. The security of most of them is based on the Diffie-Hellman (DH) problems over a group. But these types of DH problems are solvable in the presence of quantum computers. Thus, we require a non-DH type key exchange scheme that resists to the quantum computers and new modern technologies. In this paper, 2 novel lattice-based authenticated key exchange (LB-AKE) protocols, (1) using a signature-based authenticator and (2) using a signcryption-based authenticator, are devised in Canetti-Krawczyk proof model. The security of proposed protocols depends on the hardness of small integer solutions on the lattice. An extensive proof of security to our claim is given. The proposed AKEs characterize faster computation speed and resistance to the modern complex computers. [ABSTRACT FROM AUTHOR]

Authenticated key exchange protocols represent an important cryptographic mechanism that enables several parties to communicate securely over an open network. Elashry, Mu, and Susilo proposed an identity-based authenticated key exchange (IBAKE) protocol where different parties establish secure communication by means of their public identities.The authors also introduced a new security notion for IBAKE protocols called resiliency, that is, if the secret shared key is compromised, the entities can generate another shared secret key without establishing a new session between them. They then claimed that their IBAKE protocol satisfies this security notion. We analyze the security of their protocol and prove that it has a major security flaw, which renders it insecure against an impersonation attack. We also disprove the resiliency property of their scheme by proposing an attack where an adversary can compute any shared secret key if just one secret bit is leaked. [ABSTRACT FROM AUTHOR]

In this paper, the random access procedure of Universal Mobile Telecommunications System network is investigated. We have proposed a model based on communicating timed automata that represents the main functions related to the random access procedure including the user equipment, the base station (node B or BTS), and the channel. Then, we have used computational tree logic formula to specify the proprieties to be verified. The model and the formulas serve as inputs to the model checker, which is used as a verification engine, ie, UPPAAL and SPIN. The formal verification approach shows that the protocol has several drawbacks that may not be detected by simulation. [ABSTRACT FROM AUTHOR]

With the rapid demand for various increasing applications, the internet users require a common secret key to communicate among a group. The traditional key exchange protocols involve a trusted key generation center for generation and distribution of the group key among the various group members. Therefore, the establishment of a trusted key generation center server and the generation (and distribution) of common session key require an extra overhead. To avoid this difficulty, a number of group key exchange protocols have been proposed in the literature. However, these protocols are vulnerable to many attacks and have a high computational and communication cost. In this paper, we present an elliptic curve cryptography-based authenticated group key exchange (ECC-AGKE) protocol, which provides better security and has lower computational cost compared to related proposed schemes. Further, a complexity reduction method is deployed to reduce the overall complexity of the proposed elliptic curve cryptography-based authenticated group key exchange protocol. The security of proposed work is ensured by the properties of elliptic curves. A security adversarial model is given and an extensive formal security analysis against our claim is done in the random oracle model. We also made a comparison of our proposed protocol with similar works and found that ours have better complexity, security and efficiency over others. [ABSTRACT FROM AUTHOR]

Underwater Acoustic Sensor Networks (UW-ASN) are provisioned with limited bandwidth, long variable propagation delay, limited available energy, highly unreliable acoustic channels, and random node mobility. Consequently, efficient data routing between source destination pair requires UW-ASN to apply a technology different than terrestrial networks. For the past few years researchers have proposed many robust and efficient routing protocols for UW-ASN, thus reviewing the challenges posed by stringent underwater environment. These protocols can be broadly categorized into localization based and localization-free protocols. This paper presents a critical review of beacon-based localization-free routing protocols and suggest possible solution to improve the working of studied beacon based protocols. This work categorizes beacon based protocols into hop-by-hop, end-to-end, single, and multiple parameters based forwarding protocols. This categorization will help to differentiate and identify the requirements for the development of new beacon-based protocols. Finally, this paper presents performance comparison based on simulation results and outlines the research gap and future directions. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the problem of secure communication for a scenario, which consists of one pair of source-destination nodes and one untrusted relay. The source communicates with the destination via the help of energy harvesting-aware untrusted relay, which acts as the helper to forward the source information to the destination; however, the relay also acts as the unintended user to eavesdrop the source information. To keep the source information confidential from untrusted relay, the destination-assisted jamming technique is deployed. We evaluate the impact of energy harvesting protocols on such a secure communication scenario through the proposed energy transfer protocols, namely, source-based energy harvesting protocol and maximum energy harvesting protocol. To evaluate the secrecy performance of these proposed schemes, we derive analytical expressions for two important performance metrics including intercept probability and strictly positive secrecy capacity. The numerical analysis reveals the different trade-off between secure performance and relevant system parameters (i.e., power splitting ratio, time switching ratio, energy conversion efficiency, transmit signal-to-noise ratio, and relay location). Simulation results are also provided to demonstrate the accuracy of the developed analytical expression. [ABSTRACT FROM AUTHOR]

The wireless regional area networks (WRANs) operates in the very high frequency and ultra high frequency television white space bands regulated by the IEEE 802.22 standard. The IEEE 802.22 standard supports Extensible Authentication Protocol (EAP)-based authentication scheme. Due to the participation of a server and the information exchanged between a customer primes equipment and the secondary user base station, it takes around 50 ms to complete a complete EAP authentication that cannot be accepted in a handover procedure in WRANs. In this paper, we propose an EAP-based proxy signature (EPS) handover authentication scheme for WRANs. The customer primes equipment and secondary user base station accomplish a handover authentication without entailing the server by using the proxy signature. Approved by the logic derivation by Burrows, Abadi, and Needham logic and formal verification by Automated Validation of Internet Security Protocols and Applications, we can conclude that the proposed EPS scheme can obtain mutual authentication and hold the key secrecy with a strong antiattack ability. Additionally, the performance of the EPS scheme in terms of the authentication delay has been investigated by simulation experiments with the results showing that the EPS scheme is much more efficient in terms of low computation delay and less communication resources required than the security scheme regulated in IEEE 802.22 standard. [ABSTRACT FROM AUTHOR]

Authentication is the first step toward establishing a service provider and customer association. In a mobile network environment, a lightweight and secure authentication protocol is one of the most significant factors to enhance the degree of service persistence. This work presents a secure and lightweight keying and authentication protocol suite termed time-assisted authentication protocol (TAP). The TAP improves the security of protocols with the assistance of time-based encryption keys and scales down the authentication complexity by issuing a reauthentication ticket. While moving across the network, a mobile customer node sends a reauthentication ticket to establish new sessions with service-providing nodes. Consequently, this reduces the communication and computational complexity of the authentication process. In the keying protocol suite, a key distributor controls the key generation arguments and time factors, while other participants independently generate a keychain based on key generation arguments. We undertake a rigorous security analysis and prove the security strength of TAP using communicating sequential processes and rank function analysis. [ABSTRACT FROM AUTHOR]

We develop a general class of response-adaptive Bayesian designs using hierarchical models, and provide open source software to implement them. Our work is motivated by recent master protocols in oncology, where several treatments are investigated simultaneously in one or multiple disease types, and treatment efficacy is expected to vary across biomarker-defined subpopulations. Adaptive trials such as I-SPY-2 (Barker et al., 2009) and BATTLE (Zhou et al., 2008) are special cases within our framework. We discuss the application of our adaptive scheme to two distinct research goals. The first is to identify a biomarker subpopulation for which a therapy shows evidence of treatment efficacy, and to exclude other subpopulations for which such evidence does not exist. This leads to a subpopulation-finding design. The second is to identify, within biomarker-defined subpopulations, a set of cancer types for which an experimental therapy is superior to the standard-of-care. This goal leads to a subpopulation-stratified design. Using simulations constructed to faithfully represent ongoing cancer sequencing projects, we quantify the potential gains of our proposed designs relative to conventional non-adaptive designs. [ABSTRACT FROM AUTHOR]

Smart card-based client-server authentication protocol is well popular for secure data exchange over insecure and hostile networks. Recently, Lee et al. put forward an authentication protocol by utilizing ElGamal cryptosystem and proved that it can withstand known security threats. This article evinces that the protocol of Lee et al. is unwilling to protect various important security vulnerabilities such as forgery attack and off-line password-guessing attack. To vanquish these loopholes, this article presents a robust authentication protocol for client-server communication over any insecure networks. The security explanation of our protocol has done through the formal and informal mechanism and its outcome makes sure that the designed protocol is strong enough to resist the known vulnerabilities. In addition, we have simulated our protocol using ProVerif online software and its results certify that our protocol is safe against private information of the client and server. This paper also has made performance estimation of the presented protocol and others, and the outcome favors the presented protocol. [ABSTRACT FROM AUTHOR]

The growing popularity of multimedia applications and services needs to support several quality of service metrics such as high throughput, low energy, and jitter, which is a challenging task in mobile ad hoc networks. Because of limited bandwidth, energy constraints, dynamic topology, transmission errors, and fluctuating link stability, the links between adjacent nodes are often not reliable and may break because of node mobility. Link breakage initiates the process of rerouting either at the sender node (the node at which the link breaks) or at the source node. In either case, it leads to packet loss, delivery delays, and increased control overheads. Hence, to attain a minimum quality of service, routing protocols must address the dynamic network topology. Uncertain and varying movement of nodes necessitates stability of the links between such nodes. The objective of this paper is to propose 2 protocols, the first based on link stability and the other based on route stability. Link stability identifies a stable link from the available links to the next hop and determines a stable end-to-end route. The probability of successful transmission of periodic packets is used as a link stability metric to assess the stable path. Acknowledgment -free packets are used to check connectivity in the network. Increased probability of successful transmission implies that the selected link is sustained for longer duration and can deliver packets more reliably or, as a consequence, results in a stable link to deliver a better data rate. With a stable link, there is a reduced possibility of retransmissions, reduced end-to-end delay, reduced control overheads, and enhanced data delivery ratio. Selection of the most stable route for data transmission improves the performance. Experimental results from simulations performed on EXata/Cyber v2.0 simulator reveal that our proposed protocols are an improvement over the existing protocols in terms of packet delivery ratio, average end-to-end delay, and average route lifetime, even without route optimization with the minor increase in control packets. A case study of the application of proposed protocols is also presented. [ABSTRACT FROM AUTHOR]

The recent progresses made in microelectronics and sensor networks led to the emergence of a new family of networks called Internet of things (IoT). Several factors may degrade seriously IoT applications performance and prevent the connected objects to accomplish out their services. One factor is the inability of medium access control (MAC) protocol, namely, DCF 802.11 function, to distinguish between different sources of frame losses. To address this problem, we propose in this article an improvement called MAC protocol with distinction between data losses (MAC-DL), which consists mainly to consider the different sources of frame losses in the functioning of the backoff algorithm. After the evaluation of MAC-DL performance, the results showed a better performance compared with MAC protocol with the original DCF 802.11 function and to 2 other protocols proposed in the literature. Our solution improved significantly the quality of service and the energy efficient for typical IoT scenarios. [ABSTRACT FROM AUTHOR]