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The emerging use of multi-homed wireless devices along with simultaneous multi-path data transfer offers tremendous potentials to improve the capacity of multi-hop wireless networks. The use of simultaneous data transfer over separate disjoint paths in multi-hop wireless networks to increase network capacity is a less explored subject, mainly because of the challenges it triggers for the reliable transport layer protocols. Reliable transport layer protocols generally use packet sequence number as a mean to ensure delivery. As such, the out-of-order packet arrival in reliable transport layer protocols triggers receiver buffer blocking that causes throughput degradation and prevents the reliable multi-path transport layer protocol to realize its vast potential. This paper focuses on integrating network coding with a reliable multi-path transport layer protocol to resolve the receiver buffer blocking problem. We propose an adaptive network coding mechanism to desensitize the receiver against packet reordering and consequently eliminate the receiver buffer blocking problem. Our state-of-the-art network coding scheme uses a combination of Q-learning and logistic regression for rare data events to control the number of redundant packets based on the network dynamics. We confirmed the veracity of our proposed scheme by a queuing theory based mathematical model. Moreover, the effectiveness of the proposed scheme is demonstrated through simulations and testbed experiments. [ABSTRACT FROM AUTHOR]

Broadcasts for duty-cycled wireless sensor networks (WSNs) has been extensively studied recently. However, in this paper, we investigate a constraint-based forwarding for multi-hop broadcasts in asynchronous duty-cycled operations, and propose a novel Delay-Constrained and Energy-Balanced broadcast protocol called DCEB protocol. In DCEB protocol, without any central node, a distributed algorithm for constructing a broadcast backbone is presented, including its energy-balanced maintenance mechanism. Then, the decision conditions for broadcast forwarding time with or without delay constraint are deduced. Different from current studies, DCEB neither assumes time synchronization for sleep scheduling, which requires all neighboring nodes to wake up at the same time, nor assumes duty-cycled awareness, which makes the protocol difficult to use in duty-cycled WSNs. Under different network configurations, we evaluate DCEB protocol with real sensors and confirm that DCEB reduces much more broadcast cost by the decision conditions and provides better broadcast performance than the Unicast Scheme. [ABSTRACT FROM AUTHOR]

The increasingly dense deployments of wireless CSMA networks arising from applications of Internet-of-things call for an improvement to mitigate the interference among simultaneous transmitting wireless devices. For cost efficiency and backward compatibility with legacy transceiver hardware, a simple approach to address interference is by appropriately configuring the carrier sensing thresholds in wireless CSMA protocols, particularly in dense wireless networks. Most prior studies of the configuration of carrier sensing thresholds are based on a simplified conflict graph model, whereas this paper considers a realistic signal-to-interference-and-noise ratio model. We provide a comprehensive study for two effective wireless CSMA protocols: Cumulative-interference-Power Carrier Sensing and Incremental-interference-Power Carrier Sensing, in two aspects: (1) static approach that sets a universal carrier sensing threshold to ensure interference-safe transmissions regardless of network topology, and (2) adaptive approach that adjusts the carrier sensing thresholds dynamically based on the feedback of nearby transmissions. We also provide simulation studies to evaluate the starvation ratio, fairness, and goodput of our approaches. [ABSTRACT FROM PUBLISHER]

Concurrent MAC protocols can improve channel usage of wireless sensor networks (WSNs), and provide a high-performance infrastructure for data intensive applications. Most of the existing concurrent MAC protocols are based on proactively constructed physical interference models, i.e., PRR-SINR models (PSM). However, it incurs relatively high bandwidth and energy overheads to construct PSM for WSNs. In this paper, we propose NoPSM, which does not take PSM as base to determine transmission concurrency. Instead, the base of NoPSM is reactively constructed interference relationships by passively analyzing overlapping relationships among time logs of block data transmissions and corresponding reception status of each packet in blocks. In this way, NoPSM has two salient features. First, NoPSM is able to construct interference relationships among nodes quickly and accurately along with block data transmissions without needs of network downtime. Second, based on the constructed interference relationships, NoPSM can make decisions of transmission concurrency with a comprehensive criterion, which not only estimates quality of any active links after initiating a new link, but also estimates throughput improvement gained from concurrent transmissions. NoPSM has been implemented in Tinyos-2.1 and extensively evaluated in TOSSIM. Experimental results show that NoPSM improves system throughput by up to 60 percent compared with a traditional CSMA protocol, which cannot exploit potential transmission concurrency. Moreover, NoPSM can gain up to 55 percent throughput improvement as compared to an existing reactive concurrent MAC. [ABSTRACT FROM PUBLISHER]

With the rapid increase of space applications, the amount of information to be transmitted between spacecrafts and ground stations increases exponentially and space–sky–ground Transport Control Protocol (TCP) network is highly demanded. However, the traditional TCP cannot be directly applied to space data communication. This article deeply studies the TCP/Network Coding (NC), which can effectively improve terrestrial wireless communication system throughput. Combined with characteristics of Space Communication Protocol Specification-Transport Protocol (SCPS-TP) and advantages of terrestrial TCP/NC, an improved protocol referred to as SCPS-TP/NC, is proposed for space data communication. This article provides detailed process of protocol design, mathematical modelling and throughput analysis of the proposed SCPS-TP/NC. Finally, we implement the SCPS-TP/NC protocol and evaluate its performance by Network Simulator (Version 2). Simulation results show that SCPS-TP/NC can effectively increase the end-to-end system throughput, reduce the packet loss rate, shorten the transmission delay and improve the Quality of Service (QoS) of space data communication to a certain degree. [ABSTRACT FROM AUTHOR]

In case of detector network the nodes loss some quantity of energy once performing the communication. To boost the lifetime of network a energy economical communication approach is needed. In case of multicast network an collective approach is employed by LEACH protocol by creation of chain of nodes. The given work is the improvement over the LEACH protocol individual to some parameter. Here we are proposing the three call parameters to pick following node in network. These parameters embrace the space, energy and also the residual energy. The projected work can improve the potency even in case of engorged and congested network and improve the network life. Sensing element network is the large set of small sensors that transfer small piece of data. As it forms a huge range of sensors it suffers from the matter of QOS. Every sensing element node consumes some energy with totally different communication operations. If no external energy is provided to them, a sensing element can be dead because it participates for long-standing within the communication. The planned work is proposed to improve the network life-time in case of LEACH protocol. It's a Cluster based protocol and transfer information to at least one of its neighbor node supported distance. During this planned work we are going to take the choice primarily based on the remaining energy on transmission. If the remaining energy is a smaller amount than the threshold, it'll communicate to some compromising node rather than effective distance node. The work is about to provide higher utilization of energy and to enhance the node and network life. [ABSTRACT FROM AUTHOR]

This paper investigates collaborative spectrum sharing (CSS) for which a cognitive secondary transmitter acts as a decode-and-forward (DF) relay for two primary users (PUs) occupying an interfering multiple-access channel. PUs are assumed to send their signals simultaneously; hence, interference between the primary signals exists due to the multiple-access nature. The secondary user (SU) selects and forwards one of the PU's signals to a desired destination, and at the same time, the SU also transmits its own signal only if it is not harmful to PUs. The selection of a primary signal to relay is investigated, depending on SU's knowledge of two primary source–destination channels, for which closed-form outage probabilities for PUs and SU are provided accordingly. With the help of the closed-form PU's outage probability, an optimal selection strategy between the primary signals and an optimal power allocation between the primary and secondary signals are also obtained in closed form, which minimizes SU's outage probability while keeping the PU's outage performance at an SU-free level. Numerical investigation is used to verify and illustrate the analysis given in this paper. Numerical results also show that the SU's performance can vary significantly according to the amount of channel knowledge that the SU can have. [ABSTRACT FROM PUBLISHER]

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]

In this paper, we consider the joint design of data compression and 802.15.4-based medium access control (MAC) protocol for smartgrids with renewable energy. We study the setting where a number of nodes, each of which comprises electricity load and/or renewable sources, report periodically their injected powers to a data concentrator. Our design exploits the correlation of the reported data in both time and space to efficiently design the data compression using the compressed sensing technique and the MAC protocol so that the reported data can be recovered reliably within minimum reporting time. Specifically, we perform the following design tasks: (i) we employ the two-dimensional (2D) compressed sensing technique to compress the reported data in the distributed manner; (ii) we propose to adapt the 802.15.4 MAC protocol frame structure to enable efficient data transmission and reliable data reconstruction; and (iii) we develop an analytical model based on which we can obtain efficient MAC parameter configuration to minimize the reporting delay. Finally, numerical results are presented to demonstrate the effectiveness of our proposed framework compared with existing solutions. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article refers to the impact of damage and dynamic variables on operation of routing protocols and consequently to the whole network (Technical Object - TO) determining its reliability and effectiveness. On this purpose, there was introduced the characteristic of the routing protocols and both an internal and an exterior gateway. Then, it was built the network architecture based on the TCP/IP stack. In the stack, there were created three autonomous systems and one of them was the backbone of the network. What is more, reliability tests, which have been performed, consisted of a resistance to physical damage to the network and dynamically changing parameters of the network as well as performance test. [ABSTRACT FROM AUTHOR]

In wireless sensor networks, in order to satisfy the requirement of long working time of energy-limited nodes, we need to design an energy-efficient and lifetime-extended medium access control (MAC) protocol. In this paper, a node cooperation mechanism that one or multiple nodes with higher channel gain and sufficient residual energy help a sender relay its data packets to its recipient is employed to achieve this objective. We first propose a transmission power optimization algorithm to prolong network lifetime by optimizing the transmission powers of the sender and its cooperative nodes to maximize their minimum residual energy after their data packet transmissions. Based on it, we propose a corresponding power-optimized cooperative MAC protocol. A cooperative node contention mechanism is designed to ensure that the sender can effectively select a group of cooperative nodes with the lowest energy consumption and the best channel quality for cooperative transmissions, thus further improving the energy efficiency. Simulation results show that compared to typical MAC protocol with direct transmissions and energy-efficient cooperative MAC protocol, the proposed cooperative MAC protocol can efficiently improve the energy efficiency and extend the network lifetime. [ABSTRACT FROM AUTHOR]

The paper presents StegBlocks, which defines a new concept for performing undetectable hidden communication. StegBlocks is a general approach for constructing methods of network steganography. In StegBlocks, one has to determine objects with defined properties, which will be used to transfer hidden messages. The objects are dependent on a specific network protocol (or application) used as a carrier for a given network steganography method. Moreover, the paper presents the approach to perfect undetectability of network steganography, which was developed based on the rules of undetectability for general steganography. The approach to undetectability of network steganography was used to show the possibility of developing perfectly undetectable network steganography methods using the StegBlocks concept. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Network steganography conceals the transfer of sensitive information within unobtrusive data in computer networks. So-called micro protocols are communication protocols placed within the payload of a network steganographic transfer. They enrich this transfer with features such as reliability, dynamic overlay routing, or performance optimization - just to mention a few. We present different design approaches for the embedding of hidden channels with micro protocols in digitized audio signals under consideration of different requirements. On the basis of experimental results, our design approaches are compared and introduced into a protocol engineering approach for micro protocols. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Energy conserving MAC protocols performing adaptive duty-cycling mechanism have been widely studied to improve the energy efficiency in Wireless Sensor Networks (WSNs). In particular, several asynchronous low power listening (LPL) MAC protocols such as B-MAC, X-MAC and ContikiMAC transmit a long preamble or consecutive data packets for an efficient rendezvous between senders and receivers. However, the rendezvous results in the challenging problem of unnecessary channel utilization since the senders occupy a large portion of the medium. Furthermore, when a traffic generation time overlaps with other neighbouring nodes, they frequently encounter spatially-correlated contention incurring excessive channel contention. In this paper, we propose a novel traffic distribution scheme called an Energy Efficient Transmission Alignment (EETA), that shifts a traffic generation time of the application layer. By using a MAC layer feedback including contention information, the cross-layer framework determines whether the node delays its transmission or not. EETA is robust from the heavy contending environment due to its traffic distribution feature. We evaluate the performance of EETA through diverse experiments on the TelosB platform. The results show that EETA improves the overall energy efficiency by up to 35%, and reduces the latency by up to 48% compared to the existing scheme. [ABSTRACT FROM AUTHOR]

In the next-generation technology, Internet of Things (IoT), billions of smart objects will communicate with one another to make human lives more convenient. IoT is based on wireless sensor network (WSN), and Zigbee is one of the most popular WSN protocols. A mature IoT environment involves heavy WSN data transmission causing bottleneck problems. However, Zigbee’s AODV routing stack does not have load balance mechanism to handle bursty traffic. Therefore, we develop Multipath Load Balancing (MLB) Routing to substitute Zigbee’s AODV routing. Our proposed MLB consists of two main designs: LAYER_DESIGN and LOAD_BALANCE. LAYER_DESIGN assigns nodes into different layers based on node distance to IoT gateway. Nodes can have multiple next-hops delivering IoT data. All neighboring layer nodes exchange flow information containing current load, used by LOAD_BALANCE to estimate future load of next-hops. With MLB, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balance and avoid bottlenecks. Compared with Zigbee’s AODV and multipath version AODV (AOMDV), experiment results demonstrate that MLB achieves better load balance, lower packet loss rate, and better routing connectivity ratio in both grid and random uniform topologies. MLB provides a more convincing routing solution for IoT applications. [ABSTRACT FROM AUTHOR]

Transmission of system-critical control information plays a key role in efficient management of limited wireless network resources and successful reception of payload data information. This paper uses an orthogonal frequency division multiplexing (OFDM) architecture to investigate the detection performance of a time-domain approach used to detect deterministic control signalling information. It considers a type of control information chosen from a finite set of information, which is known at both transmitting and receiving wireless terminals. Unlike the maximum likelihood (ML) estimation method, which is often used, the time-domain detection technique requires no channel estimation and no pilots as it uses a form of time-domain correlation as the means of detection. Results show that when compared with the ML method, the time-domain approach improves detection performance even in the presence of synchronisation error caused by carrier frequency offset. [ABSTRACT FROM AUTHOR]

In the active queue management (AQM) scheme, core routers cannot manage and constrain user datagram protocol (UDP) data flows by the sliding window control mechanism in the transport layer due to the nonresponsive nature of such traffic flows. However, the UDP traffics occupy a large part of the network service nowadays which brings a great challenge to the stability of the more and more complex networks. To solve the uncontrollable problem, this paper proposes a cross layers random early detection (CLRED) scheme, which can control the nonresponding UDP-like flows rate effectively when congestion occurs in the access point (AP). The CLRED makes use of the MAC frame acknowledgement (ACK) transmitting congestion information to the sources nodes and utilizes the back-off windows of the MAC layer throttling data rate. Consequently, the UDP-like flows data rate can be restrained timely by the sources nodes in order to alleviate congestion in the complex networks. The proposed CLRED can constrain the nonresponsive flows availably and make the communication expedite, so that the network can sustain stable. The simulation results of network simulator-2 (NS2) verify the proposed CLRED scheme. [ABSTRACT FROM AUTHOR]

Passive optical networks are widely used as a promising solution for future access networks. Currently, the bandwidth is still increasing which means the current copper networks are not able to transfer new services such as 4K video, live streaming, etc. In other words, they reached their capacity limit. The passive optical networks rely on point-to-multipoint technology. That means each customer uses a share medium by time slots. Each time slot exactly specifies who and when is able to transfer data. In general, this control mechanism is implemented in the optical network unit by worst transmission convergence layer. On the other hand, there are cases when the optical network unit (it is called rogue optical network unit) does not follow instructions provided by the optical line termination, for example, if an attacker modifies a firmware of the end unit and/or when the control protocol is not loaded properly inside optical network unit. In worst case, the optical network unit transmits data in a continual mode (other optical network units cannot send data). The standard defines finding of the rogue optical network unit but it does not specify how the rogue optical network unit should be allocated because the frames of the rogue optical network unit do not contain the proper parameters. We realized a measurement in a real network with the rogue optical network unit and then we analyzed the captured data. A new algorithm for the rogue optical network unit allocation is presented. We do not consider any modification of the transmission convergence layer in gigabit passive optical networks. [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]

We propose an underwater CSMA/CA protocol with multi-RTS and multi-DATA receptions using the long underwater propagation delay. We analyze the throughput and delay of the proposed underwater CSMA/CA protocol through a ring-based underwater network modeling. The proposed protocol does not need to maintain the information of internode propagation delay for each pair of underwater nodes. In the proposed protocol, when there are simultaneous transmissions of RTS frames from different underwater sensors to an underwater sink as their back-off counters reach zero, the sink can recover some RTS frames which are not overlapped at the sink in the time domain due to the long underwater propagation delay. Then, the sink transmits CTS frame containing the DATA transmission order and the IDs of the sensors which transmitted the recovered RTS frames. Sensors which correspond to the IDs contained by the CTS frame can transmit DATA frame to the sink according to the DATA transmission order. We evaluate the throughput and delay performance of the proposed protocol with varying the number of sensors and the contention window size compared to the conventional protocols. The analytical results agree with the simulation results well for the proposed protocol with various numbers of sensors and contention window sizes. The analytical and simulation results show that the proposed protocol outperforms the conventional protocols. [ABSTRACT FROM AUTHOR]

Many applications of wireless sensor networks (WSNs) require events be detected around moving targets and delivered to a user, whose location may also change over time. Consequently, it is not desirable to have a single sensor node serving as the sink node for centralized event processing. Furthermore, an event usually occurs across different locations and lasts for a period of time that are unknown in advance. Hence it cannot be detected by a static set of sensor nodes. In this paper, we propose a general framework for such dynamic in-network event detection in WSNs. This framework enables a flexible number of sensor nodes to dynamically collaborate in detecting and delivering any specified event. So far there has been no such work reported in the literature. We have designed a protocol for the sensor nodes to autonomously determine whether they should participate in and which tasks they should perform to collaboratively process an event. We have implemented a prototype of the proposed framework using MicaZ motes and evaluated it through both simulations and experiments. The results demonstrate that our framework is effective and efficient in terms of energy cost and event processing delay. [ABSTRACT FROM AUTHOR]

This paper focuses on the event based investigations over different data dissemination routing protocols for highly dense wireless sensor networks. Initially for the wireless sensor network domain, we analyzed data dissemination flooding and gossiping routing protocols. We etude and exemplify our proposed model for data dissemination based evaluation with Delphi random generator distribution strategy. We calculated performance metrics as sense count, transmit count, receive count and receive redundant count. At the end, simulations analysis has been carried out to prove the validity of our designed scenario. [ABSTRACT FROM AUTHOR]

Buffer sizing is an important network configuration parameter that impacts the quality of service characteristics of data traffic. With falling memory costs and the fallacy that "more is better," network devices are being overprovisioned with large buffers. This may increase queueing delays experienced by a packet and subsequently impact stability of core protocols such as TCP. The problem has been studied extensively for wired networks. However, there is little work addressing the unique challenges of wireless environments such as time-varying channel capacity, variable packet inter-service time, and packet aggregation, among others. In this article we discuss these challenges, classify the current state-of-the-art solutions, discuss their limitations, and provide directions for future research in the area. [ABSTRACT FROM PUBLISHER]

Oncology practice increasingly requires the use of molecular profiling of tumors to inform the use of targeted therapeutics. However, many oncologists use third-party laboratories to perform tumor genomic testing, and these laboratories may not have electronic interfaces with the provider's electronic medical record (EMR) system. The resultant reporting mechanisms, such as plain-paper faxing, can reduce report fidelity, slow down reporting procedures for a physician's practice, and make reports less accessible. Vanderbilt University Medical Center and its genomic laboratory testing partner have collaborated to create an automated electronic reporting system that incorporates genetic testing results directly into the clinical EM R. This system was iteratively tested, and causes of failure were discovered and addressed. Most errors were attributable to data entry or typographical errors that made reports unable to be linked to the correct patient in the EMR. By providing direct feed back to providers, we were able to significantly decrease the rate of transmission errors (from 6.29% to 3.84%; P < .001). The results and lessons of 1 year of using the system and transmitting 832 tumor genomic testing reports are reported. [ABSTRACT FROM AUTHOR]

In ad hoc networks, broadcastbased forwarding protocols called opportunistic routing have been proposed. In general backoff-based opportunistic routing protocols, each receiver autonomously makes a forwarding decision using a random backoff time based on logical distance. However, each potential forwarder must wait for the expiration of the backoff timer before the packet forwarding. Moreover, they cannot gain forwarding path diversity in sparse environments. In this paper, we propose a novel forwarder selection method for opportunistic routing. In the proposed method, a terminal called, a prioritized forwarder, and which is selected from among neighbours and can forward packets without using the backoff time. In addition, we integrate a hop-by-hop retransmission control in the proposed method, which improves the packet transmission success rate in sparse environments. We evaluate the proposed method in comparison with the conventional protocols in computer simulations. [ABSTRACT FROM AUTHOR]

Among synchronization protocols applied in wireless sensor network, reference broadcast synchronization (RBS) is one prominent protocol achieving very high accuracy of synchronization given that the broadcasting medium is available. However, that the protocol lacks packet loss tolerance brings about degraded performance in severe conditions of wireless channel. Also, the instantaneous synchronization used in this protocol results in time discontinuity, which might cause serious faults in the distributed system. In this study, we propose a packet loss tolerance and continuous synchronization mechanism for RBS. Then we verified the result through simulations. [ABSTRACT FROM AUTHOR]

SUMMARY The efficiency of medium access control strongly influences the performance of distributed wireless networks. Collisions in the channel and unused timeslots result in poor performance. On the other hand, quantum superdense coding proved that entanglement-assisted quantum communications can improve the data transmission rates compared with classical systems. It allows sending two classical bits from one party to another in exchange of one quantum bit and a pre-shared entangled Bell pair. This paper introduces a new protocol, which involves a modified version of superdense coding to medium access control of distributed communication systems. Using a pre-shared entangled Bell pair and one classical bit, 2.5 classical bits can be transmitted in average between the parties in each timeslot. This means not only valuable increase in capacity, but the two-way distributed operation opens new fields of investigation. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cooperative retransmission can significantly improve link reliability over lossy and time-varying wireless links. However, comparing retransmission protocols is challenging, and generally requires simplistic assumptions specific to each protocol. In this paper, we develop a general model to evaluate cooperative retransmission protocols with distributed, slot-based contention algorithms. Specifically, we propose to calculate the relay time-out probabilities at a MAC time-slot scale, formulate retransmission outcomes as functions of the time-out probabilities, and derive the probability of a retransmission process for every data frame. We also propose a Markov extension of our model to characterise the dependency between retransmissions of multiple frames. This enables our model to analyse continuous retransmissions of successive frames. Validated by QualNet simulations, our model can analytically predict the probabilities of cooperative retransmissions with an accuracy of $\pm 1$ %. As a result, direct comparisons between cooperative retransmission protocols become tangible, without implementing the full protocol in a state-based simulator. [ABSTRACT FROM PUBLISHER]

The reliable data delivery is a challenging task in Wireless Sensor Networks (WSNs) due to dynamic and unpredictable changing behaviors of nodes. The traditional cryptographic and authentication based schemes can't be adopted due to their associated cost and incapability to counter nodes misbehavior attacks. Recently, trust based solutions have proved to be more effective to address nodes' misbehavior attacks. Apart from isolating misbehaving nodes, the existing trust based schemes lacks the capability to minimize link failure notifications due to transient transmission disruption which consequently give rise to frequent route breakages thereby undermining throughput and route stability. Moreover, the existing solutions give rise to high energy consumption and control overhead in pursuit of trust estimation and network-wide dissemination which not only adds to network congestion but also undermines network lifetime. In this paper, we present a Trust and Energy aware Routing Protocol (TERP) that makes use of a distributed trust model for the detection and isolation of misbehaving nodes. TERP incorporates a composite routing function that encompasses trust, residual-energy, and hop count of neighbor nodes in making routing decisions. This multi-facet routing strategy helps to balance out energy consumption among trusted nodes while routing data using shorter paths. Moreover, TERP intelligently evaluates the actual link breakage thereby avoiding unnecessary route discoveries. Simulation results demonstrate improved throughput, network lifetime and route stability of TERP when compared to existing work. [ABSTRACT FROM AUTHOR]

We focus on the design of transmission protocol for energy harvesting wireless sensors. The sensors can harvest the energy from the environment, but they cannot charge and discharge at the same time. We propose a protocol for energy harvesting and wireless transmission, which contains two steps. In the first step, the sensor harvests the energy from environment, and the energy harvesting rate is controlled by the harvested energy power of the energy saving device (ESD). In the second step, some data should be transmitted to the receiver in a certain time. Considering one slot time, the first part of the time is devoted exclusively to energy harvesting, and the remaining time of the slot is for transmitting the information data. Assume that Q bits are transmitted to the receiver within one time slot; we establish the relationship between the harvesting energy time and the transmit data time. In addition, we analyze the system outage probability performance over the Rayleigh fading channel. [ABSTRACT FROM AUTHOR]

This article presents new metric for TCP connection robustness evaluation and comparison. This metric is focused on TCP connection and transmission continuity rather then on maximal throughput or minimal RTT. This metric is developed especially for evaluation of narrow band networks. That is why it is very convenient to use this metric for networks such as Internet of Things networks or industrial sensor networks. Our metric is based on observing if connections or transmissions are successfully finished or not. It is possible to optimize this metric for specific situations. This metric can be used in both the real networks and in discrete simulation environments. [ABSTRACT FROM AUTHOR]

The increase in the rate of the data transmission leads to the overhead in the MAC. The existing Frame aggregation techniques lead to the lower throughput as the data is transferred at lowest rate of aggregated frames. This paper designs a framework that adapts the rate of frames to increase the throughput. The simulation verifies the optimization of the process. The increase in the throughput and the decrease in the delay verifies the significance of the proposed technique. [ABSTRACT FROM AUTHOR]

In the recent years, low power computing systems have gained popularity. Networks, which use low power computer systems and transmit data by using wireless connection, are called wireless sensor networks. Nowadays, the most topical studies are aimed at grouping wireless sensor networks by the new optimisation of structure of network transmission protocol, the routing optimisation in a transmission network, optimisation of network structure, as a result of which it is possible to increase the life cycle of wireless network sensors. There are a number of methods that allow solving this problem. These include the choice of the capacity of individual battery, the deployment of the node density, the adjustment of power transmitter, the application of energy-efficient data transfer protocol, positioning of network nodes and other methods that are associated with the introduction of additional network costs. The present article discusses a new method for balancing energy through the mobility of network node intellectual agent, which provides the opportunity for reconfiguration of dynamic network or change of network topology. [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]

An underwater acoustic network simulation methodology is presented that is based on lookup tables (LUTs) with physical-layer error ratios. These LUTs are prepared with a validated replay channel simulator, which is here driven by channel measurements from the Kauai Acomms MURI 2011 (KAM11) experiment. Three physical-layer candidates are considered: a coherent single-carrier scheme, a coherent multicarrier scheme, and an incoherent scheme. The three modulation schemes are operated at a fixed message size and at four different data rates. Low rates are more robust to noise, interference, and channel dispersion, but also more prone to collisions in a network with busy traffic, because the packets are longer. Error statistics for colliding packets have been measured and are incorporated in the network simulator as collision LUTs. Example simulations are presented for a reduced flooding protocol with or without retransmissions. The results demonstrate how retransmissions pose a tradeoff between performance at high and low traffic load. The best network performance is obtained if the highest data rate is selected that yields a reasonably well-connected network. Collision avoidance is more important than the extended connectivity offered by low-rate signaling. On the other hand, at a given bit rate, a physical-layer scheme with extended connectivity but relatively weak links is shown to outperform a scheme with stronger links over fewer connections. [ABSTRACT FROM PUBLISHER]

Wireless protocol is the load control method to be used on the DHCP method. The replacement of cable by the personal area network on the flow of the various loads. the communication are transfer on the interconnection on the flow of the data. DHCP -Dynamic host Control protocol. Power load monitoring System. The usage and service options of a public network generally differ from a private (enterprise or home) network and consequently, the two networks are often configured differently, the existing system cannot monitor external devices power. The proposed method for DHCP algorithms used to monitor internal and external devices are used in the network . in this paper have been implemented and deployed currently being used in a real-world public network The various loads and external device Efficient Power utilization through real time power consumption with help of monitoring Computer Based GUI. [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]

Liu, Y.; Xu, Y.; Zhang, K., and Feng, Y., 2019. Hardware design of marine buoy data communication terminal based on the 1st generation Beidou navigation positioning system. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 639–645. Coconut Creek (Florida), ISSN 0749-0208. Aiming at the actual situation of marine buoy data monitoring and the problems of poor anti-interference performance, low fault tolerance coefficient and high energy consumption in current communication system, the hardware design of marine buoy data communication terminal based on the 1st generation Beidou navigation positioning system is proposed. Based on the marine buoy system, the overall structure of communication terminal is designed. The main components of the hardware are Beidou communication module and wireless network communication module, and the auxiliary parts are antenna and power supply module. The long-distance part uses the inherent data transmission mode of Beidou navigation system to communicate, while the short-range part uses the radio network communication protocol to complete the data transmission. There are two UART interfaces in the hardware, one is connected with the auxiliary cabin, which is responsible for receiving the related data of the auxiliary cabin, including azimuth, attitude and pressure sensing, and the other UART interface is connected with the Beidou communication module, which is responsible for receiving positioning and navigation data and transmitting remote data. The experimental results show that the design has high signal-to-noise ratio, strong fault-tolerant performance, high positioning accuracy and communication success rate, low energy consumption and perfect performance. [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]

Accurately estimating node density in Vehicular Ad hoc Networks, VANETs, is challenging and crucial task. Various approaches exist, yet none takes advantage of physical layer parameters in a distributed fashion. This paper describes a framework that allows individual nodes to estimate the node density of their surrounding network independent of beacon messages and other infrastructure-based information. The proposal relies on three factors: 1) a discrete event simulator to estimate the average number of nodes transmitting simultaneously; 2) a realistic channel model for VANETs environment; and 3) a node density estimation technique. This work provides every vehicle on the road with two equations indicating the relation between 1) received signal strength versus simultaneously transmitting nodes, and 2) simultaneously transmitting nodes versus node density. Access to these equations enables individual nodes to estimate their real-time surrounding node density. The system is designed to work for the most complicated scenarios where nodes have no information about the topology of the network and, accordingly, the results indicate that the system is reasonably reliable and accurate. The outcome of this work has various applications and can be used for any protocol that is affected by node density. [ABSTRACT FROM AUTHOR]

Achieving same notion of time remains an important task for most distributed systems. Time synchronization requires a unique combination of high accuracy ( $$\upmu $$ s level) and energy efficiency. Several application layer protocols have been developed to meet these requirements. This article proposes that the physical layer clock recovery process can provide application layer clock drift estimate, and the application layer clock can be corrected with the help of this estimate. This eliminates the need of application layer time synchronization protocol i.e. the cross-layer approach reduces the number of message exchanges required by application layer for time synchronization that leads to energy conservation. It argues that such a cross-layer approach can provide a more accurate frequency offset estimation, or can achieve greater energy savings, for a given accuracy, by reducing the message exchanges. Analysis of the proposed method provides concrete bounds on achieved improvement. Experimental evaluation showed that physical layer clock drift can be used to correct application layer clock drift as they are identical. [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]