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Filtered Smith predictors are well established for controlling linear plants with constant time delays. Apart from this classical application scenario, they are also employed within networked control loops, where the measurements are sent in separate packets over transmission channels that are subject to time-varying delays. Consequently, classical tools for the stability analysis, e.g., for time delay systems, have to be extended to facilitate an explicit consideration of network-induced effects such as packet skipping and disordering of sent packets. The present paper illustrates that the time-varying delays and, particularly important, the packetized character of the transmissions have to be explicitly taken into account for the stability analysis. Three network protocols, which use different packet selection and hold mechanisms, are considered to state criteria for the robust stability of the networked feedback loops with filtered Smith predictors. They are based on the small gain theorem and allow a computationally inexpensive way to check stability for the case with uncertain plant models and bounded time-varying packet delays in the communication channels. • Filtered Smith predictor for packet-based networked systems. • Communication network with bounded and time-varying packet delays. • Three different network protocols (different packet skipping and hold mechanisms). • Easy-to-use stability analysis for uncertain plants and time-varying packet delays. [ABSTRACT FROM AUTHOR]

In view of the security threats posed inside and outside the network due to the weaknesses of network protocols and systems, power line and wireless converged communications have security problems in communication connections that appear in environments where heterogeneous networks overlap. In order to cope with the problems of network delay and data transmission security in smart grid, this paper proposes an online monitoring security protection method based on edge nodes, which manages user trust under the premise of not leaking grid user data, and establishes a personalized machine learning model. This method not only guarantees users a secure communication experience, but also ensures users' real-time network connection and content acquisition, and can obtain a fast and personalized user experience. [ABSTRACT FROM AUTHOR]

In this paper, the distributed set-membership filtering problem is investigated for general nonlinear systems subject to Round-Robin and stochastic communication protocols over sensor networks. The considered disturbances are assumed to be unknown but bounded within certain known ellipsoidal regions. Two types of frequently used protocols, i.e., the Round-Robin and stochastic communication protocols are adopted separately to regulate the data transmission among sensor nodes. According to the Round-Robin protocol, each node is able to receive information from only one of its neighboring nodes in a circular order at each time step, whereas the stochastic communication protocol allows each node randomly receive the information sent from one of the neighboring nodes. By resorting to the recursive linear matrix inequalities approach, sufficient conditions are established for the existence of the desired distributed filter, guaranteeing that the state estimates are constrained within certain pre-determined ellipsoidal regions at each time step. Then two optimization problems aiming to minimize the ellipsoids (in the sense of matrix trace) are put forward to seek the locally optimal filtering performance. Finally, simulation examples are given to illustrate the effectiveness of the proposed algorithms. [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]

Fiber-Wireless (FiWi) networks typically combine an optical access network with a wireless access network so as to build on the respective strengths of the optical and wireless network technologies. Prior analytical throughput-delay studies of FiWi networks have typically considered heavy-loaded traffic models, i.e., constantly backlogged source nodes. In contrast, in this paper we present a more general comprehensive FiWi network throughput-delay analysis that encompasses Poisson (non-heavy) as well as heavy-loaded input traffic models. In addition, our analysis covers bandwidth assignments of wireless channels both at the hop distance level and at the node level, as well as a queuing model of dynamic bandwidth allocation in the optical access network. Our analysis provides insightful guidelines for setting the channel access probabilities for source traffic and relay traffic in FiWi networks. Our numerical evaluations demonstrate that prior studies which considered only heavy traffic loads gave misleading results for the delay performance of well-known access probability assignments. We correct and clarify these misleading results with our more general analysis for non-heavy traffic. [ABSTRACT FROM AUTHOR]

In hostile environments where explosives and natural calamities probably occur, wireless sensor networks (WSNs) are susceptible to multiple collocated failures and could be partitioned into disjoint segments. Federating the segments would be essential for restoring connectivity and enabling data sharing in the network. The federation may be achieved by populating relay nodes and providing perpetual inter-segment paths. In this paper, we tackle the federation problem while considering constrained relay availability, i.e., a limited number ( k ) of mobile relays to provide intermittent inter-segment connectivity that makes the problem more challenging. We propose LEEF, a novel algorithm for achieving energy-efficient federation with low inter-segment data delivery latency. LEEF strives to group the segments into k clusters in a star topology where a cluster at the center of the area serves as a hub between each pair of segment-clusters. Each cluster is served by a distinct mobile relay. In addition, LEEF opts to equalize the energy consumed by the k mobile relays due to travel and wireless communication. We analyze the properties of LEEF mathematically and validate its performance through extensive simulation experiments. [ABSTRACT FROM AUTHOR]

Abstract: Full duplex wireless communication is one of the enabling technologies of the fifth generation (5G) mobile telecommunication networks. It boosts up the bandwidth by enabling simultaneous data transmission and reception on a single channel. In this paper, we design a suitable medium access control (MAC) protocol for 5G networks to realize the benefit of full duplex communication. We also develop an analytical model to evaluate the performance of our proposed MAC protocol. [ABSTRACT FROM AUTHOR]

Code Division Multiple Access, which allows multiple users to access and transmit data over wireless channel simultaneously, is implemented using different code assignment schemes including Pair-wise Code Assignment. In this paper, the existing pair-wise code assignment procedure is enhanced and a new such scheme is presented with at most ∆ codes, where ∆ is the maximum degree of a network. In addition, a co-channel interference called secondary interference that exists in the existing schemes has been addressed and an interference free pair-wise code assignment procedure is proposed with at most ∆ 2 - c codes, where c is a constant. On simulation over different synthesized, actual and random networks, it is found that our scheme improves successful transmission rate and blocking probability by 17% and 12.5% respectively. Although the code requirement of the proposed interference free scheme is increased by 40%, it would improve the network performance. [ABSTRACT FROM AUTHOR]

VANETs have emerged as an exciting research and application area. Increasingly vehicles are being equipped with embedded sensors, processing and wireless communication capabilities. This has opened a myriad of possibilities for powerful and potential life-changing applications on safety, efficiency, comfort, public collaboration and participation, while they are on the road. Although, considered as a special case of a Mobile Ad Hoc Network, the high but constrained mobility of vehicles bring new challenges to data communication and application design in VANETs. This is due to their highly dynamic and intermittent connected topology and different application’s QoS requirements. In this work, we survey VANETs focusing on their communication and application challenges. In particular, we discuss the protocol stack of this type of network, and provide a qualitative comparison between most common protocols in the literature. We then present a detailed discussion of different categories of VANET applications. Finally, we discuss open research problems to encourage the design of new VANET solutions. [ABSTRACT FROM AUTHOR]

As VLSI technology advances, the number of modules on a chip multiplies and thus the solutions for on-chip communication are evolving to support the new paradigm in inter-module communication on System on Chip (SOC). Those System on Chip, Current chip designs incorporate more complex multilayered and stack segmented interconnection buses with various routing architectures results in a Network on Chip. These, traditional solutions, which were based on a combination of shared-buses and dedicated module-to-module wires, scalability limit, and are no longer adequate for System on Chip/Network on Chip. On-chip architectures have been optimized for a non-chip environment before the multi-core challenge became the focus of processor chip architecture through the latency and the throughput. This evolution of on-chip interconnects may evoke feelings of among networking old-timers. The considerations that have driven data communication from shared buses to packet-switching networks and to routing protocols such as spatial reuse, multi-hop routing, flow and congestion control etc., will inevitably drive the challenges raised in the design of network interfaces with the segmented stack layered mechanism, and potentially managing the critical resources designed for on-chip modules. [ABSTRACT FROM AUTHOR]

Radio Frequency Identification (RFID) has been widely adopted in practice for objects identification. The ownership of an object can be represented by the ownership of the RFID tag attached to the object. An ownership could be shared among different parties and should be transferable. Although many RFID ownership transfer protocols were proposed, a shared ownership transfer protocol remains as a daunting task with absence of a trusted party. In this paper, we propose the first provably secure shared ownership transfer protocol, which requires merely hashing computations and has a constant key size. [ABSTRACT FROM AUTHOR]

With the growing demand for X-ray imaging experiments, the area and performance of pixel array detectors continue to improve, and the readout of massive data gradually becomes a thorny problem. In Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE), the data rate of its high frame rate pixel detector is expected to exceed Tbps in the future. Traditional gigabit and ten-gigabit networks can no longer meet the readout requirements and the transmission bandwidth of the readout system has turned into a bottleneck. Combined with the state-of-the-art developments in the network, two FPGA-based 100G readout solutions are developed. The first solution, NET-CONV, can extract the raw data from the network packet and aggregate data streams from multiple 10G links into one 100G link. It supports parallel transmission of up to 12 channels and achieves a peak rate of 94 Gbps in the test. NET-TOE is developed as the second solution, which aims to improve the transmission speed of the Ethernet ports further. It implements a complete network protocol stack at 100 Gbps line rate, supporting maximum transmission unit (MTU) adjustment, TCP window scale, and UDP. The actual measurement indicates that the maximum data transmission rate reaches 97 Gbps. [ABSTRACT FROM AUTHOR]

In this paper, we present an investigation of MAC protocols for linear wireless sensor networks (LWSNs). Recently, there have been a number of applications like roads, bridges and pipeline monitoring, in which the transmission of data over very long lines of consecutive nodes is required. Due to the additional restrictions imposed by the linear topology, such applications present new challenges regarding the provision of low latency and low energy consumption. In order to address these issues researches have proposed a number of protocols tailored specifically for linear topologies. Two different operational mechanisms stand out: the first is based on explicit book and burst transmission, while the second is based on low power listening (LPL) and adaptive sleep cycle. The paper covers the details of the operation of these two types of protocols and provides simulation results for their performance comparison in terms of latency, energy consumption and throughput. The results clearly show the limitations of burst transmission and the advantages of LPL and adaptive sleep cycle as realized in LINE_MAC. [ABSTRACT FROM AUTHOR]

There is a significant interest in new wireless multiple access protocols that adaptively split a wide frequency channel into multiple sub-channels—perhaps of varying widths—and assign these sub-channels to competing transmissions. Existing protocols suffer from various limitations such as considerable protocol overhead, dependence on a centralized controller, and use of fixed-size channels. We introduce Ez-Channel, a novel MAC protocol that parsimoniously utilizes the OFDM sub-carriers to perform channelization and assignment of sub-channels to competing links. In addition to circumventing hidden and exposed terminal problems, Ez-Channel adapts channel assignments to the network topology. To eliminate the need for a centralized controller and to avoid an overwhelming amount of information exchange, the protocol uses a randomization technique enabling provably efficient localized decision making. Our extensive analytical and simulation studies show that Ez-Channel yields significant throughput improvements as compared to the state-of-the-art protocols. [ABSTRACT FROM AUTHOR]

Mobile Adhoc Networks is a self organizing network composed of mobile terminals connected by wireless links. Adhoc Networks are created dynamically without any preexisting network infrastructure Ad-hoc networks are very useful in situations like emergency search and reuse operations and meetings where people want to quickly share information. This network does not have any central administration, hence there are no designated routes, all the nodes can serve as routers for each other, and data packets are forwarded from node to node to node in multi hop fashion. Cluster based Mobility and Energy Aware (CMEA) routing protocols is used to find the reliable route in a cluster networks. The clustered network avoids path breaks and long path delay. When applying the energy and mobility aware metric over clustered network gives reliable route between Source and Destination. Service Oriented Architecture (SOA) is an evolution of past platforms, preserving successful characteristics of traditional architectures and bringing with it distinct principles that follow service orientation in support service oriented enterprise. It forces the network to improve the reliability, security, integrity etc. By applying the proposed XML technique for encrypting the secure data improves the content delivery over the CMEA network. Therefore SOA based secure data transmission over the reliable route improves the network performance. [ABSTRACT FROM AUTHOR]

The major concerns for the 5th generation wireless systems are to provide higher data rates and higher transmission quality in the wireless network environment. Cooperative relaying as a promising technology has widespread attention, since it can achieve higher transmission quality and throughput for wireless networks. This paper aims at maximizing throughput and transmission quality by minimizing frame error rate (FER) as minimum as possible. Relay selection is an effective technique to improve the system performance in wireless networks by allowing users to cooperate with each other in their transmissions to achieve high transmission quality and diversity. This paper proposes an efficient relay selection scheme for WiMAX network with selection combining technique using amplify and forward and decode and forward protocols by analyzing the FER. FER approximation model based on improved signal to noise ratio was developed. In the proposed relay model, signals at the receiver are combined using selection combining technique. In maximum ratio combining (MRC) based cooperative relay systems, only the correctly detected signal will be forwarded by the relay and the performance will be worse under poor channel conditions. So the relay selection is done with selection combining technique. Simulation results exhibit the effectiveness of two relaying protocols amplify and forward (AF) and decode and forward (DF) individually and at high signal to noise ratio (SNR) region FER has been reduced in DF protocol than AF protocol. Based on the suppression of noise and effective retrieval of information, DF protocol is found to be more effective compared to AF protocol. The proposed structure is evaluated using performance parameters such as FER and SNR. Structural realization and analysis pertaining to Power and Throughput are implemented in MATLAB. Power allocation for water filling, optimal and sub optimal algorithms are analyzed for various channels. Simulation results have proven that suboptimal algorithm performs closer to optimal algorithm and water filling power allocation scheme outperforms both optimal and suboptimal scheme. High throughput is obtained by reducing the FER in DF protocol compared to AF protocol that improves the transmission quality of WiMAX networks. A throughput greater than 9.5 Gbps can be achieved using DF protocol which increases the speed of 5G network up to 10 Gbps. [ABSTRACT FROM AUTHOR]

In this paper the broadcast relay channel, where the source communicates with multiple destinations with the help of a single relay is studied. Five different transmission protocols, direct transmission, multihop (MH), multihop with link combination (MHLC), path selection (PS) and path selection with link combination (PSLC) are investigated. In MH and MHLC, the relay decodes the source message and assists both destinations. In PS and PSLC, the relay can perform partial decoding and has the option to help only one of the destinations. Under long-term power constraint, power allocation for delay-limited transmission is performed to minimize common outage probability and individual outage probability region. For comparison, lower bounds on both common and individual outage probabilities are found. Numerical results suggest that path selection significantly lowers outage probabilities, while enforcing the relay to help both destinations simultaneously is limiting the system performance. [ABSTRACT FROM AUTHOR]

Nodes in wireless multi-hop networks establish links with their neighbors, which are used for data transmission. In general, in this kind of networks every node has the possibility of acting as a router, forwarding the received packets when they are not the final destination of the carried data. Due to the routing protocol procedures, when the network is quite dense the overload added by the routing management messages can be very high. To reduce the effects of this overload a topology control mechanism can be used, which can be implemented using different techniques. One of these techniques consists of enabling or disabling the routing functionality in every node. Many advantages result from selecting just a subset of nodes for routing tasks: reduction of collisions, protocol overhead, interference and energy consumption, better network organization and scalability. In this paper, a new protocol for topology control in wireless mesh networks is proposed. The protocol is based on the centrality metrics developed by social network analysts. Our target network is a wireless mesh network created by user hand-held devices. For this kind of networks, we aim to construct a connected dominating set that includes the most central nodes. The resulting performance using the three most common centrality measures (degree, closeness and betweenness) is evaluated. As we are working with dynamic and decentralized networks, a distributed implementation is also proposed and evaluated. Some simulations have been carried out to analyze the benefits of the proposed mechanism when reactive or proactive routing protocols are used. The results confirm that the use of the topology control contributes to a better network performance. [ABSTRACT FROM AUTHOR]

The two important requirements for many Wireless Senor Networks (WSNs) are prolonged network lifetime and end-to-end reliability. The sensor nodes consume more energy during data transmission than the data sensing. In WSN, the redundant data increase the energy consumption, latency and reduce reliability during data transmission. Therefore, it is important to support energy efficient reliable data transport in WSNs. In this paper, we present a Hierarchical Energy Efficient Reliable Transport Protocol (HEERTP) for the data transmission within the WSN. This protocol maximises the network lifetime by controlling the redundant data transmission with the co-ordination of Base Station (BS). The proposed protocol also achieves end-to-end reliability using a hop-by-hop acknowledgement scheme. We evaluate the performance of the proposed protocol through simulation. The simulation results reveal that our proposed protocol achieves better performance in terms of energy efficiency, latency and reliability than the existing protocols. [ABSTRACT FROM AUTHOR]

The benefits of hop-by-hop transport protocols and in-network storage in intermittently connected networks are well known. However, due to the limitation on the storage capability of wireless sensor networks (WSNs), the hop-by-hop transport protocols based on in-network storage but without storage management are inappropriate to be used directly in intermittently connected WSNs. The absence of storage management leads to node storage overflow resulting in a degraded performance of the network. This paper introduces an efficient transport protocol, Dacksis , which provides end-to-end reliability, congestion control and storage management for intermittently connected wireless sensor networks. The design of Dacksis is based on hop-by-hop transport and in-network storage, therefore, the system can react to detected network congestion quickly and can reduce the number of end-to-end packet retransmissions. The storage management feature of Dacksis saves node storage for unconfirmed packets, which decreases the possibility of buffer overflow and packet queuing time, and reduces energy spent on loss recovery. Dacksis forgoes link layer per-packet acknowledgments and transmits packets in blocks to reduce energy consumption. The block size of Dacksis is dynamically determined before each hop-by-hop transmission to enhance the utilization of node storage. [ABSTRACT FROM AUTHOR]

The location-based routing protocol has been chosen as one of the efficient routing approaches in vehicular ad hoc networks in terms of low overhead and high scalability. Its critical advantage lies in performing a pathless routing such that a node having a packet forwards it to its neighbor node that provides the shortest physical distance to destination and this process continues until the packet reaches destination. The problem lies in that the link stability of the neighbors varies largely depending on the mobility of vehicles and the environmental factors that incur shadowing and fading effects. In this paper, we propose a new link quality prediction metric associated with location based protocols to improve the selection of next hop, that consider both the link quality assessment based on the transmission success rate and the link quality assessment based on the prediction of the future locations of vehicles. Simulation results are presented to demonstrate the efficiency of the proposed metric. [ABSTRACT FROM AUTHOR]

Abstract: DCCP (Datagram Congestion Control Protocol) is a transport layer protocol that provides congestion control for unreliable data transmission. The congestion control mechanism embedded in DCCP adjusts the packet sending rate according to network condition. However, DCCP does not discriminate congestion losses and wireless link errors resulted from fading and thus it leads to unnecessary rate adjustment. In this paper, we proposed a mechanism to enhance bandwidth utilization of DCCP over wireless network. We employed a cross-layer loss discrimination scheme to distinguish congestion loss and fading loss. The cross-layer based mechanism detects frame loss in the data link layer in real-time to infer the actual fading loss rate. Thereafter, the fading loss can be excluded from the packet loss observed in the transport layer. Once the accurate congestion loss rate is calculated, the sender can make appropriate adjustment on the transmission rate that reflects the current congestion state along the transmitting path using the DCCP rate control procedure. Simulation results show that DCCP with our proposed CCID 3 rate control scheme can discriminate fading loss and achieve from 4.7% to 15.5% improvement on transmission throughput when the fading loss rate varies from 5% to 15% in wireless network. [Copyright &y& Elsevier]

Abstract: With the tremendous growth of the usage of computers over network and development in application running on various platform captures the attention toward network security. This paradigm exploits security vulnerabilities on all computer systems that are technically difficult and expensive to solve. Hence intrusion is used as a key to compromise the integrity, availability and confidentiality of a computer resource. The Intrusion Detection System (IDS) plays a vital role in detecting anomalies and attacks in the network. In this work, data mining concept is integrated with an IDS to identify the relevant, hidden data of interest for the user effectively and with less execution time. Four issues such as Classification of Data, High Level of Human Interaction, Lack of Labeled Data, and Effectiveness of Distributed Denial of Service Attack are being solved using the proposed algorithms like EDADT algorithm, Hybrid IDS model, Semi-Supervised Approach and Varying HOPERAA Algorithm respectively. Our proposed algorithm has been tested using KDD Cup dataset. All the proposed algorithm shows better accuracy and reduced false alarm rate when compared with existing algorithms. [Copyright &y& Elsevier]

Abstract: Tag cloning attacks threaten a variety of Radio Frequency Identification (RFID) applications but are hard to prevent. To secure RFID applications that confine tagged objects in the same RFID system, this paper studies the cloned-tag identification problem. Although limited existing work has shed some light on the problem, designing fast cloned-tag identification protocols for applications in large-scale RFID systems is yet not thoroughly investigated. To this end, we propose leveraging broadcast and collisions to identify cloned tags. This approach relieves us from resorting to complex cryptography techniques and time-consuming transmission of tag IDs. Based on this approach, we derive a time lower bound on cloned-tag identification and propose a suite of time-efficient protocols toward approaching the time lower bound. The execution time of our protocol is only 1.4 times the value of the time lower bound, being over 91% less than that of the existing protocol. Even better, we further dig up an adaptive protocol that can yield higher time efficiency under some scenarios. The proposed protocols may benefit also RFID applications that distribute tagged objects across multiple places. [Copyright &y& Elsevier]

Abstract: We introduce a new approach to channel access for ad hoc networks that utilize multiple heterogeneous channels. The radios of the ad hoc networks we investigate are frequency-agile allowing them the ability to change their carrier frequency and transmission rate over a wide range of possibilities. Our approach to channel access takes advantage of the multiple frequency bands available to the network to increase network-layer performance. We have previously found that in some network scenarios, the best network-layer performance is achieved if the channel-access protocol always selects the channel with the fastest data rate that is immediately available. However, in other network scenarios it is preferable to always wait for a channel with a faster data rate that is temporarily unavailable to become available rather than select a channel with a slower data rate that is immediately available. We show that our new channel-access protocol is able to adapt the strategy for selecting channels so that high network-layer performance is maintained in all scenarios compared to channel-access protocols that utilize either fixed strategy. [Copyright &y& Elsevier]

Abstract: In this paper, we discuss the design of a new Medium Access Control (MAC) protocol, SRI-MAC (Synchronous Receiver Initiated MAC), for wireless sensor networks whose goal is to extend the lifetime of the network by avoiding major energy waste causes, such as collisions, overhearing and idle listening. SRI-MAC is designed on the basis of synchronized duty cycled MAC protocols. The nodes in SRI-MAC synchronize each other to avoid data packet collisions. SRI-MAC uses receiver-initiated data transmission in order to efficiently and effectively operate over a wide range of traffic loads. It employs an adaptive beacon and a series of RTS/CTS (Request To Send/Clear To Send) packets to reduce duty cycle and minimize idle listening. In SRI-MAC, the senders remain active and wait silently until the receiver explicitly signifies when to start data transmission by sending CTS packet. If the node is not the intended sender, it returns to sleep immediately and continues its sleep as if the medium had been idle. Analytical and Simulation results show that SRI-MAC reduces the energy consumption and achieves an obvious improvement on the network lifetime. [Copyright &y& Elsevier]

Highlights: [•] There is a lack of end-to-end security mechanisms tailored to IP-enabled sensors. [•] Ladon is proposed as end-to-end authentication and authorization protocol. [•] We evaluate the time and energy cost of executing Ladon on the protected sensors. [•] Ladon is proved to be a suitable security protocol for resource-deprived devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] A hybrid multicast–unicast data transmission model for DDM in HLA is presented. [•] A new adaptive communication protocol selection strategy is proposed. [•] A concept of distance is presented to support the assignment decision. [•] The utilization of multicast and unicast communication resources can be higher. [Copyright &y& Elsevier]

Abstract: Wireless NanoSensor Networks (WNSNs), i.e., networks of nanoscale devices with unprecedented sensing capabilities, are the enabling technology of long-awaited applications such as advanced health monitoring systems or surveillance networks for chemical and biological attack prevention. The peculiarities of the Terahertz Band, which is the envisioned frequency band for communication among nano-devices, and the extreme energy limitations of nanosensors, which require the use of nanoscale energy harvesting systems, introduce major challenges in the design of MAC protocols for WNSNs. This paper aims to design energy and spectrum-aware MAC protocols for WNSNs with the objective to achieve fair, throughput and lifetime optimal channel access by jointly optimizing the energy harvesting and consumption processes in nanosensors. Towards this end, the critical packet transmission ratio (CTR) is derived, which is the maximum allowable ratio between the transmission time and the energy harvesting time, below which a nanosensor can harvest more energy than the consumed one, thus achieving perpetual data transmission. Based on the CTR, first, a novel symbol-compression scheduling algorithm, built on a recently proposed pulse-based physical layer technique, is introduced. The symbol-compression solution utilizes the unique elasticity of the inter-symbol spacing of the pulse-based physical layer to allow a large number of nanosensors to transmit their packets in parallel without inducing collisions. In addition, a packet-level timeline scheduling algorithm, built on a theoretical bandwidth-adaptive capacity-optimal physical layer, is proposed with an objective to achieve balanced single-user throughput with infinite network lifetime. The simulation results show that the proposed simple scheduling algorithms can enable nanosensors to transmit with extremely high speed perpetually without replacing the batteries. [Copyright &y& Elsevier]

Abstract: The design of the readout and data acquisition system of the future KM3NeT neutrino telescope employs 10Gbps photonic technologies for data transmission to shore. The photonic architecture can handle standard transmission protocols. The generic scheme is based on DWDM technology using lasers on shore and optical modulators in each of the 12,800 Digital Optical Modules arranged on several hundred vertical detection units anchored to the seabed. Each module will house 31 photomultipliers together with auxiliary instrumentation and readout electronics. A 100km electro-optical fibre cable will connect the optical modules to the store. The readout system will guarantee an individual optical connection between each optical module and the shore. A small-scale prototype of a detection unit with four optical modules is in a realization phase and will allow for in situ testing of the data transmission network. We will present results of laboratory tests of the photonics-oriented transmission layer of the network that have been realized for the prototype detection unit. [Copyright &y& Elsevier]

The lightweight sensors gain rapid growth for the development of emerging technologies due to multi aspects. Recently, many applications are integrating with the cloud services for storage and processing a large amount of observing data, however, the transitory and time-dependent environment needs valuable performance. Also, reliable and error-free data transmission is an important factor for green systems. Moreover, most of the proposed green networks may be exposed to unspecified events due to the broadcast nature of the unreserved medium. This research paper presents a secured mobile sensor network based protocol for smart data gathering with cloud services (S-SDC), which aims to attain information distribution in dynamic networks using mobile sensors with minimum loss and power consumption. Also, it ensures network availability and consistency for the collected data with the cloud corporations and increases authoritative routing. The simulation results and their analysis are proven the significant performance of the proposed protocol. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: In vehicular ad hoc networks, many applications require a low latency and high reliability especially the safety applications. Reliable multi-hop broadcast protocols have been widely discussed recently. However, most of them use explicit acknowledgments and timeout retransmissions to provide reliability. The retransmission method incurs delays when a packet loss cannot be detected on time. Acknowledgment messages also increase the MAC layer contention time at each node. In order to provide a high reliability and low latency with a low overhead, we propose a mechanism which utilizes path diversity. In the proposed mechanism, a message is delivered through two different paths. By cooperation of these different paths, broadcast messages can be disseminated with a short delay and a high reliability compared with the acknowledgment based retransmission approach. Since the proposed mechanism does not use any explicit acknowledgment message, the message overhead is low. We evaluate the proposed mechanism using both theoretical analysis and computer simulations. [Copyright &y& Elsevier]

Abstract: An unreliable wireless communication environment and limited energy resources have a severe impact on the Quality of Service (QoS) of Mobile Ad Hoc Networks (MANETs). To improve network performance, an Energy-balanced Cooperative Media Access Control (EC-MAC) protocol in MANETs is proposed in this paper. It adopts the best partnership selection algorithm based on opportunistic relaying to select the cooperative node with the best channel conditions, highest transmission rate and most balanced energy consumption. The simulation results of EC-MAC, Cooperative MAC (CoopMAC) and IEEE 802.11 Distributed Coordination Function (DCF) protocols show that EC-MAC outperforms the other two protocols in terms of the packet delivery ratio, network throughput and network lifetime under two distinct channel noise levels, especially under the bad channel condition. Meanwhile, the EC-MAC protocol does not increase the average end-to-end delay compared with IEEE 802.11 DCF. [Copyright &y& Elsevier]

Abstract: Multimedia communication networks, such as the Internet, are heterogeneous in their nature because they require different methods for content transmission. The efficiency of multimedia content transmission depends on the variety of communication protocols that are simultaneously running (composed) over different network hosts in order to resolve packet conflicts. A very natural question that arises in such common settings of multimedia networks concerns the degradation (or not) of network stability under adversarial attacks that change dynamically network link capacities/slowdowns. A packet-switched network is stable if the number of packets in the network remains bounded at all times against any adversary. In this work, we embark on a systematic study of this question adopting an enhanced adversarial framework, where an adversary controls the rates of packet injections, determines packet paths and manipulates link slowdowns or capacities. Such adversarial attacks can be considered as a type of denial of service attack. Within this framework, we study network stability under specific compositions of contention–resolution protocols when packets are injected with simple paths (paths can contain repeated edges, but not repeated nodes) trying to characterise this property in terms of network topologies. The examined network topologies have been proved forbidden for stability when network link capacities/slowdowns are fixed and packet paths are simple. Furthermore, in order to evaluate how unstable can a network be for the same protocol compositions under dynamic adversarial attacks, we present an involved adversarial construction that leads a specific network to instability for arbitrarily low injection rates. Interestingly, our results suggest that dynamic adversarial attacks changing link slowdowns may be worse than dynamic adversarial attacks changing link capacities or attacks with fixed slowdowns/capacities for specific protocol compositions. [Copyright &y& Elsevier]

Abstract: ADELIN (ADaptive rELIable traNsport) protocol is a reliable transport protocol only based on FEC (Forward Error Correction) for UASN (Underwater Acoustic Sensor Networks). In cooperative scenario, ADELIN improves its reliability of data packet transmission further by forwarding node redundancy, which wastes the limited energy and bandwidth of nodes. In this paper, the IPool-ADELIN protocol is proposed and shown to help reduce energy consumption. In IPool-ADELIN, by overhearing the data transmissions, the IPool node not only relays the data packets, which are not implicitly acknowledged, but also does local link maintenance when the BER (Bit Error Rate) of the monitored link is high. The results of mathematical analysis and simulations show that IPool-ADELIN has a higher data delivery ratio and lower energy consumption. [Copyright &y& Elsevier]

Abstract: Gossiping, which broadcasts the message of every node to all the other nodes, is an important operation in multi-hop wireless networks. Interference-aware gossiping scheduling (IAGS) aims to find an interference-free scheduling for gossiping with the minimum latency. Previous work on IAGS mostly assumes that nodes are always active, and thus is not suitable for duty-cycled scenarios. In this paper, we investigate the IAGS problem in uncoordinated duty-cycled multi-hop wireless networks (IAGS-UDC problem) under protocol interference model and unbounded-size message model. We prove that the IAGS-UDC problem is NP-hard. We propose two novel algorithms, called MILD and MILD-R, for this problem with an approximation ratio of at most 3β 2(Δ +6)∣T∣, where β is , α denotes the ratio of the interference radius to the transmission radius, Δ denotes the maximum node degree of the network, and ∣T∣ denotes the number of time slots in a scheduling period. The total numbers of transmissions scheduled by both two algorithms are at most three times as large as the minimum total number of transmissions. Extensive simulations are conducted to evaluate the performance of our algorithms. [Copyright &y& Elsevier]

Abstract: Wireless Sensor Networks (WSNs) consist of large number of randomly deployed energy constrained sensor nodes. Sensor nodes have ability to sense and send sensed data to Base Station (BS). Sensing as well as transmitting data to- wards BS require high energy. In WSNs, saving energy and extending network lifetime are great challenges. Clustering is a key technique used to optimize energy consumption in WSNs. In this paper, we propose a novel clustering based routing technique: Enhanced Developed Distributed Energy Efficient Clustering scheme (EDDEEC) for heterogeneous WSNs. Our technique is based on changing dynamically and with more efficiency the Cluster Head (CH) election prob- ability. Simulation results show that our proposed protocol achieves longer lifetime, stability period and more effective messages to BS than Distributed Energy Efficient Clustering (DEEC), Developed DEEC (DDEEC) and Enhanced DEEC (EDEEC) in heterogeneous environments. [Copyright &y& Elsevier]

Abstract: In critical scenarios nodes switch from low data rate of transmission mode to high data rate. Such scenarios are event driven and traffic is highly dynamic in nature. Latency and reliability issues with Quality of Service (QoS) for such applications in IEEE 802.15.4 have been an issue. The earlier schemes did address them but high data rates and channel error rates resulted in increase in contention for GTS request packets and increased data packet drop rate. In our work, we employed a mechanism to deal with isuues arising out of additional contention caused by prioritized nodes in CAP. We present an enhanced MAC scheme that incorporates two-level service differentiation through Contention Window Differentiation (CWD) and dynamic p-persistent CSMA, for mitigating the issues like lower transmission delays and higher success probability to time-critical messages in high channel error conditions. We evaluate our proposed scheme for varying channel and traffic-load conditions by simulation using Omnet+ + .The results show that performance in terms of the mentioned issues has improved significantly. Further, the energy decline rate analysis have been done for varying traffic arrival rates and compared with the original IEEE 802.15.4 and found that our scheme has less energy decline rate thus increased network lifetime. [Copyright &y& Elsevier]

Abstract: The bandwidth is one of the most precious resources in Mobile Ad Hoc Networks (MANETs); their network protocols should therefore be able to achieve an increase in efficiency of bandwidth utilisation. TCP, which implements flow control to regulate the network traffic, plays a significant role in shaping the workload of the network. However, spurious TCP retransmissions can increase the link utilisation, consequently limiting the amount of spare bandwidth available as extensively reported in the literature. This problem is exacerbated by the presence of high priority traffic and traffic differentiation introduced in IEEE 802.11e. In this paper, we focus on the optimisation of TCP for resource efficiency, by limiting the number of contention-induced retransmissions. Using a cross-layer technique, TCP can be notified of the medium contention state and adjusts its retransmission timer accordingly. Our simulation results demonstrate the effectiveness of our proposal in various scenarios. A 15% gain in resource utilisation is obtained, fewer packets are retransmitted thus reducing the overall power consumption and TCP goodput is improved. [Copyright &y& Elsevier]

Abstract: In this paper, we present a Wireless Sensor node implementation which aims at solving two major issues in Wireless Sensor Networks. This solution provides nanosecond-scale synchronization between nodes and high data-rate transmission thanks to cross-layer design and the time-domain properties of UltraWide Band (UWB) modulation schemes. The high data rate is achieved through a specific implementation of a IR-UWB physical layer. Specific algorithms are also implanted into the MAC and physical layers and form a cross-layered synchronization protocol for deterministic Wireless Sensor Networks named WiDeCS (Wireless Deterministic Clock Synchronization). This protocol propagates master time reference to nodes of a cluster tree network. WiDeCS Cross layered scheme is possible thanks to flag signals rising in the physical layer. These signals, owing to the UWB time domain properties, capture precise timestamps of transmission and reception. Hardware level simulations show a clock synchronization precision of 2ns with a 2GHz bandwidth signal, and an ASIC demonstrator shows 374ps synchronization precision and 677ps of standard deviation with the same bandwidth. In this paper, the physical layer implementation is detailed, and the cross-layered WiDeCS scheme is demonstrated. [Copyright &y& Elsevier]

Abstract: The amount of imagery that is available via various content providers grows at a staggering rate. Contemporary handheld devices allow accessing these content providers anytime, anyplace. Moreover, using the build-in camera, one can easily contribute to these online image repositories. The present lack of consistency in how repositories are accessed for retrieval or syncing complicates inter-operability between devices and systems. JPSearch, a recent standardization initiative within the Joint Photographic Experts Group (JPEG) committee, resolves this predicament by defining the interfaces and protocols for data exchange between them, while restricting as little as possible how those devices, systems or components perform their task. [Copyright &y& Elsevier]

Abstract: We propose new burst assembly schemes and fast reservation (FR) protocols for Optical Burst Switched (OBS) networks that are based on traffic prediction. The burst assembly schemes aim at minimizing (for a given burst size) the average delay of the packets incurred during the burst assembly process, while the fast reservation protocols aim at further reducing the end-to-end delay of the data bursts. The burst assembly techniques use a linear prediction filter to estimate the number of packet arrivals at the ingress node in the following interval, and launch a new burst into the network when a certain criterion, different for each proposed scheme, is met. The fast reservation protocols use prediction filters to estimate the expected length of the burst and the time needed for the burst assembly process to complete. A Burst Header Packet (BHP) packet carrying these estimates is sent before the burst is completed, in order to reserve bandwidth at intermediate nodes for the time interval the burst is expected to pass from these nodes. Reducing the packet aggregation delay and the time required to perform the reservations, reduces the total time needed for a packet to be transported over an OBS network and is especially important for real-time applications. We evaluate the performance of the proposed burst assembly schemes and show that a number of them outperform the previously proposed timer-based, length-based and average delay-based burst assembly schemes. We also look at the performance of the fast reservation (FR) protocols in terms of the probability of successfully establishing the reservations required to transport the burst. [Copyright &y& Elsevier]

Abstract: We study the problem of fast neighbor positioning and medium access in wireless networks with directional antennas. In this problem, the cross-layer dimension inherently comes into stage through the impact of PHY-layer antenna directionality on medium access. Fast neighbor positioning reduces the network initialization overhead and leaves more time for executing other protocols. Fast medium access leads to larger volume of transmitted data per unit of time. The two problems are studied in a unified manner in a system with one Access Point (AP) and multiple users around it. The AP sequentially scans the space by forming directional beams and applies contention-free or contention-based user polling within each beam. In the former method, polling messages are addressed to a specific user. In the latter, users in a beam contend to have their message received by the AP. We explore the impact of the contention resolution protocol and the directional beam width on user positioning and medium access delay. A large beam width incurs large expected delay for contention resolution due to the larger expected amount of contention in the beam, but on the other hand, it implies that fewer beams, and hence smaller delay is needed to scan the entire space. We obtain analytic expressions for the total average user positioning and the medium access delay, and we present an optimization method for minimizing it by appropriately selecting the beam width and the persistence probability of the collision resolution protocol. Our method uses accumulated knowledge from previous scans to estimate the anticipated amount of contention in upcoming scans and to adjust the beam width and persistence probability accordingly. Our numerical results demonstrate the efficiency of our techniques in terms of fast neighbor positioning. [Copyright &y& Elsevier]

Abstract: The super-module integration concept based on double-sided silicon strip modules has been developed for the future upgrade of the ATLAS detector. A super-module consists of 12 double-sided modules with 122880 readout strips in total. Since the number of readout strips becomes very large to keep the hit occupancy at an acceptable level, the data readout is one of the key issues. A SiTCP based DAQ system has been developed by using the Soi EvAluation BoArd with Sitcp (SEABAS). The SEABAS processes the data by means of an FPGA (User-FPGA) and transfers data to a computer via Ether-net with the SiTCP protocol, which is a hardware implementation of TCP/IP on a FPGA device, enabling it to achieve high speed data transfers. The firmware and software have been developed for the SEABAS together with the readout hardware chain, and the basic functionality for reading out the super-module has been established. [Copyright &y& Elsevier]

Abstract: Power efficiency and coverage preservation are two important performance metrics for a wireless sensor network. However, there is scarcely any protocol to consider them at the same time. In this paper, we propose a flow-balanced routing (FBR) protocol for multi-hop clustered wireless sensor networks that attempts to achieve both power efficiency and coverage preservation. The proposed protocol consists of four algorithms, one each for network clustering, multi-hop backbone construction, flow-balanced transmission, and rerouting. The proposed clustering algorithm groups several sensors into one cluster on the basis of overlapping degrees of sensors. The backbone construction algorithm constructs a novel multi-level backbone, which is not necessarily a tree, using the cluster heads and the sink. Furthermore, the flow-balanced routing algorithm assigns the transferred data over multiple paths from the sensors to the sink in order to equalize the power consumption of sensors. Lastly, the rerouting algorithm reconstructs the network topology only in a place where a head drops out from the backbone due to the head running out of its energy. Two metrics called the network lifetime and the coverage lifetime are used to evaluate the performance of FBR protocol in comparison with previous ones. The simulation results show that FBR yields both much longer lifetime and better coverage preservation than previous protocols. For example, FBR yields more than twice network lifetime and better coverage preservation than a previous efficient protocol, called the coverage-preserving clustering protocol (CPCP) [18], when the first sensor dies and the network coverage is kept at 100%, respectively. [Copyright &y& Elsevier]

Abstract: In multi-channel wireless networks, multi-channel diversity can increase the number of concurrent transmissions and thus improve the throughput performance as data transmission on a wireless channel does not interfere with transmissions on the other non-overlapping channels. However, multi-channel coordination may cause severe performance degradation due to hidden terminals, missing receivers, or broadcast deafness problems if the channel usage information is not properly shared among the neighboring nodes. In this paper, we devise a semi-synchronous multi-channel coordination protocol that enables wireless nodes to: (i) efficiently exchange channel and coordination information, and (ii) reduce the overhead of channel switchings. In the proposed protocol, a rendezvous interval is set up in a distributed manner depending on the traffic rate and pattern, and each node independently switches its channel when it can complete its transmissions and then returns to the control channel within the rendezvous interval. This approach makes all nodes return to the control channel at almost the same time without incurring a severe synchronization overhead. Through subsequent analyses and simulation studies, we show that the proposed protocol effectively reduces the number of channel switchings, thereby achieving higher throughput in various multi-channel networking environments. [Copyright &y& Elsevier]

Abstract: In this paper, we introduce a probabilistic routing metric that considers the peculiar characteristics of the operating environment of cognitive radio networks (CRNs). This metric captures the dynamic changes in channel availabilities due to the randomness of primary user’s activity and the rich channel diversity due to the fact that a CRN is expected to operate over highly separated frequency channels with different propagation characteristics. Our metric, Probability of Success (PoS), statistically quantifies the chances of a successful cognitive radio (CR) packet transmission over a given channel. Based on the PoS metric, we propose a joint probabilistic routing and channel assignment protocol for multi-hop CRNs that attempts at selecting the path with the maximum probability of success among all possible paths for a given CR source-destination pair. Selecting such a path results in minimizing the number of disruptions to CR packet transmissions, which consequently improves network throughput. Simulation results verify the significant throughput improvement achieved by our protocol compared to reference CRN routing protocols. [Copyright &y& Elsevier]

Abstract: Cooperative communications, in which a relay node helps the source node to deliver its packets to the destination node, are able to obtain significant benefits in terms of transmission reliability, coverage extension and energy efficiency. A Cooperative Automatic Repeat reQuest (C-ARQ) MAC protocol has been recently proposed to exploit cooperative diversity at the MAC layer. In this paper, we validate the integrity and the validity of the C-ARQ protocol using formal methods. The protocol logic is modeled in SDL and implemented in PROMELA. The functionality of the C-ARQ protocol is verified through simulations and verifications using SPIN. [Copyright &y& Elsevier]

Abstract: The IEEE 802.11n standard is defined to achieve a high throughput at the MAC layer. This high throughput is accomplished via many enhancements in both the physical and MAC layers. A key enhancement introduced in the 802.11n standard is frame aggregation. Two types of aggregation defined by the 802.11n standard, aggregate MAC service data unit (A-MSDU) and aggregate MAC protocol data unit (A-MPDU). Frame aggregation reduces both the headers and timing overheads at the MAC layer by aggregating multiple frames into a single large frame before being transmitted. The aggregation headers themselves still have a negative impact on the network performance especially when aggregating frames of small payload. Moreover, the lack of partial retransmission in the A-MSDU aggregation is behind its poor performance in error-prone channels. In this paper we proposed an optimized header A-MSDU frame aggregation (OHA-MSDU) with subframes retransmission capability at the MSDU level. The simulation results show the significance of the proposed scheme, especially for applications that have a small frame size such as VoIP. [Copyright &y& Elsevier]

Abstract: It is well known that the data of large-scale and dense wireless sensor network has high spatial correlativity. According to the monitoring of a particular event, a new medium access control (MAC) protocol based on perceived data reliability and spatial correlation is proposed in this paper. In this protocol, a ring-shaped space correlation model is established. The nodes close to information source is attributed them high priority in access channel so as to make sure the high quality data send successfully to the sink node and increase the data transferring efficiency. The new protocol can make the received data reflect the real physical phenomenon. At the same time, it can make the data transmission of the nodes far to information source be brought down and the amount of required data nodes be reduced. So the new protocol can prolong lifetime of the whole network. Our simulation results show that the new MAC protocol can supply better network service under low energy consumption and transmission delay. This is very useful for all kinds of mobile services of Internet of Things. [Copyright &y& Elsevier]