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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]

Mobile ad-hoc network has limited battery power. Power consumption control is the main issue in mobile ad-hoc network. Node battery power is a precious resource that should be used in order to avoid the early termination of nodes. Energy management model and power consumption control flow chart is proposed to control power consumption by reducing data transmit time in mobile ad-hoc network. Simulation model has been used to analysis the energy consumption of a node. This has been achieved by estimating the time spent in transmission of data by node. The proposed model has been simulated using OMNET $$++$$ simulator. Simulation results show significant energy savings after applying the proposed model and flow chart. [ABSTRACT FROM AUTHOR]

The performance of delay/disruption tolerant networking (DTN) protocols in cislunar and deep-space communication systems has previously been studied by simulation. However, little work has been seen in characterizing in an analytical manner the performance of DTN protocols for space with respect to asymmetric channel rates. We present a performance characterization of the recently developed DTN Licklider transmission protocol (LTP) convergence layer adapter (CLA) (or simply LTPCL) over cislunar space channels with data-rate asymmetry. Analytical models are built to characterize LTPCL with respect to the minimum number of bundle protocol (BP) bundles that should be aggregated to avoid delay in acknowledgment (ACK) transmission and the optimal number of bundles to be aggregated for the best transmission efficiency of BP/LTPCL, with the effect of full overhead at all layers taken into consideration. The models are validated by file transfer experiments running BP/LTPCL protocols using a PC-based testbed. [ABSTRACT FROM AUTHOR]

Wireless sensor networks with mobile sinks, mWSNs, have attracted a lot of attention recently. This is because sink mobility can greatly alleviate the hotspot issue in WSNs and further prolong the network lifetime. However, sink mobility also causes unexpected changes in network topology and data routing paths, which can largely affect the routing performance in such networks. Design of efficient routing protocols for mWSNs has been a critical issue, and much work has been carried out in this aspect. In this article, we first classify existing protocols based on different design criteria and then present a survey of the state-of-the-art routing protocols in this area. We illustrate how each of the protocols works, and discuss their advantages and disadvantages. Finally, we point out some future directions for efficient routing in mWSNs. [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]

The Ethernet switch is a primary building block for today's enterprise networks and data centers. As network technologies converge upon a single Ethernet fabric, there is ongoing pressure to improve the performance and efficiency of the switch while maintaining flexibility and a rich set of packet processing features. The OpenFlow architecture aims to provide flexibility and programmable packet processing to meet these converging needs. Of the many ways to create an OpenFlow switch, a popular choice is to make heavy use of ternary content addressable memories (TCAMs). Unfortunately, TCAMs can consume a considerable amount of power and, when used to match flows in an OpenFlow switch, put a bound on switch latency. In this paper, we propose enhancing an OpenFlow Ethernet switch with per-port packet prediction circuitry in order to simultaneously reduce latency and power consumption without sacrificing rich policy-based forwarding enabled by the OpenFlow architecture. Packet prediction exploits the temporal locality in network communications to predict the flow classification of incoming packets. When predictions are correct, latency can be reduced, and significant power savings can be achieved from bypassing the full lookup process. Simulation studies using actual network traces indicate that correct prediction rates of 97% are achievable using only a small amount of prediction circuitry per port. These studies also show that prediction circuitry can help reduce the power consumed by a lookup process that includes a TCAM by 92% and simultaneously reduce the latency of a cut-through switch by 66%. [ABSTRACT FROM AUTHOR]

CHOKe is a simple and stateless active queue management (AQM) scheme. Apart from low operational overhead, a highly attractive property of CHOKe is that it can protect responsive TCP flows from unresponsive UDP flows. Particularly, previous works have proven that CHOKe is able to bound both bandwidth share and buffer share of (a possible aggregate) UDP traffic (flow) on a link. However, these studies consider, and pertain only to, a steady state where the queue reaches equilibrium in the presence of many (long-lived) TCP flows and an unresponsive UDP flow of fixed arrival rate. If the steady-state conditions are perturbed, particularly when UDP traffic rate changes over time, it is unclear whether the protection property of CHOKe still holds. Indeed, it can be examined, for example, that when UDP rate suddenly becomes 0 (i.e., flow stops), the unresponsive flow may assume close to full utilization in sub-round-trip-time (sub-RTT) scales, potentially starving out the TCP flows. To explain this apparent discrepancy, this paper investigates CHOKe queue properties in a transient regime, which is the time period of transition between two steady states of the queue, initiated when the rate of the unresponsive flow changes. Explicit expressions that characterize flow throughputs in transient regimes are derived. These results provide additional understanding of CHOKe and give some explanation on its intriguing behavior in the transient regime. [ABSTRACT FROM AUTHOR]

In this work we study a routing scheme combined with an end-to-end rerouting procedure. We focus in particular on a new rerouting strategy called Shared Robust Rerouting (ShRR). This strategy combines three other restoration techniques, namely path diversity, end-to-end rerouting with stub release and global rerouting, in order to achieve cost-effectiveness. Computational results on the bandwidth overhead required by the proposed scheme are provided, as well as a comparison with some conventional restoration schemes. [ABSTRACT FROM AUTHOR]

This paper presents an approach to distributing traffic among capability-varying access points (APs) in wireless Local Area Networks. Under consideration is a non-homogeneous environment where maximum transport rates over radio channels differ from AP to AP. We let each new station associate itself to a best-fit AP, allowing for received signal strength, potential responsiveness, and remaining channel capacity of every AP in range. Our approach is developed for alignment with standard protocols, keeping legacy stations operable while maintaining forward compatibility. Our development augments the functionality of APs such that association is decided by APs collaboratively. Simulation results show that our approach outperforms counterpart schemes by an appreciable amount in terms of throughout, transmission delay, and load distribution. Our approach is also of avail to homogeneous network settings. Featuring simplicity and efficiency, our design lends itself to other types of contention-based wireless network like ZigBee as well. [ABSTRACT FROM AUTHOR]

Selection cooperation is an attractive cooperative strategy for wireless networks due to its simplicity and efficiency. In this paper, we consider a heterogeneous cooperative network consisting of different kinds of nodes with low-cost radios where the activities of one kind of nodes are triggered by the other kinds of nodes. This is a common scenario for many networks, such as wireless sensor networks. By exploiting the transmission relationship between heterogeneous nodes, we propose a selection cooperation protocol where inducing nodes can cooperate with the following nodes after their own transmissions for improving the communication reliability of the latter nodes. Through performance analysis, we show an interesting feature that the diversity-multiplexing tradeoff of the proposed protocol does not rely on the best relay selection method and the protocol always achieves the full diversity gain. We further develop an energy-efficient best relay selection method based on power control where the power consumption is minimized without decreasing the full diversity order. Simulation results demonstrate the good performance of the protocol and the remarkable energy reduction of the proposed best relay selection method. [ABSTRACT FROM AUTHOR]

Different medium access control (MAC) layer protocols, for example, IEEE 802.11 series and others are used in wireless local area networks. They have limitation in handling bulk data transfer applications, like video-on-demand, videoconference, etc. To avoid this problem a cooperative MAC protocol environment has been introduced, which enables the MAC protocol of a node to use its nearby nodes MAC protocol as and when required. We have found on various occasions that specified cooperative MAC establishes cooperative transmissions to send the specified data to the destination. In this paper we propose cooperative MAC priority (CoopMACPri) protocol which exploits the advantages of priority value given by the upper layers for selection of different paths to nodes running heterogeneous applications in a wireless ad hoc network environment. The CoopMACPri protocol improves the system throughput and minimizes energy consumption. Using a Markov chain model, we developed a model to analyse the performance of CoopMACPri protocol; and also derived closed-form expression of saturated system throughput and energy consumption. Performance evaluations validate the accuracy of the theoretical analysis, and also show that the performance of CoopMACPri protocol varies with the number of nodes. We observed that the simulation results and analysis reflects the effectiveness of the proposed protocol as per the specifications. [ABSTRACT FROM PUBLISHER]

The increased demand for wireless connectivity emphasizes the necessity of efficient wireless communication as resources such as the available spectrum and energy reserves become limiting factors for network proliferation. Recent advancements in software-defined radio enable high flexibility of the physical layer allowing fine grained transmission adjustments. Although communication efficiency can greatly benefit from physical layer flexibility, modern wireless protocols can neither handle these new opportunities nor allocate resources according to the overlying application needs. In this work we develop WhiteRate, a method for physical layer parameter adaptation that efficiently utilizes available energy and spectrum resources, while maintaining the desired quality of communication. Our solution adjusts the modulation and coding scheme, and channel width to achieve a communication profile that matches application requirements. We implement WhiteRate in GNUradio and evaluate it in both indoor and outdoor environments. We demonstrate improvements on two important fronts: spectrum utilization and energy efficiency. Moreover, we show that by using WhiteRate, both benefits can be achieved simultaneously. [ABSTRACT FROM AUTHOR]

Contemporary wireless multihop networks operate much below their capacity due to the poor coordination among transmitting nodes. In this paper, we present XPRESS, a cross-layer backpressure architecture designed to reach the capacity of wireless multihop networks. Instead of a collection of poorly coordinated wireless routers, XPRESS turns a mesh network into a wireless switch. Transmissions over the network are scheduled using a throughput-optimal backpressure algorithm. Realizing this theoretical concept entails several challenges, which we identify and address with a cross-layer design and implementation on top of our wireless hardware platform. In contrast to previous work, we implement and evaluate backpressure scheduling over a TDMA MAC protocol, as it was originally proposed in theory. Our experiments in an indoor testbed show that XPRESS can yield up to 128% throughput gains over 802.11. [ABSTRACT FROM AUTHOR]

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]

This paper proposes a novel exposed-terminal-eliminated medium access control (ETE-MAC) protocol by combining channel reservation, collision avoidance and concurrent transmissions to improve multi-access performance of the multihop wireless networks. Based on the proposed slot scheduling scheme, each node senses the control channel (CCH) or the data channel (DCH) to accurately determine whether it can send or receive the corresponding packets without collisions. Slot reservation on the CCH can be simultaneously executed with data packet transmissions on the DCH. Therefore, it resolves the hidden-terminal type and the exposed-terminal type problems efficiently, and obtains more spatial reuse of channel resources. Concurrent packet transmissions without extra network overheads are maximized. An analytical model combining Markov model and M/G/1 queuing theory is proposed to analyze its performance. The performance comparison between analysis and simulation shows that the analytical model is highly accurate. Finally, simulation results show that, the proposed protocol obviously outperforms the link-directionality-based dual-channel MAC protocol (DCP) and WiFlex in terms of the network throughput and the average packet delay. [ABSTRACT FROM AUTHOR]

Wireless sensor networks for industrial process monitoring and control require highly reliable and timely data delivery. To match performance requirements, specialised schedule based medium access control (MAC) protocols are employed. In order to construct an efficient system, it is necessary to find a schedule that can support the given application requirements in terms of data delivery latency and reliability. Furthermore, additional requirements such as transmission power may have to be taken into account when constructing the schedule. In this article, we show how such schedule can be constructed. We describe methods and tools to collect the data necessary as input for schedule calculation. Moreover, due to the high complexity of schedule calculation, we also introduce a heuristic.We evaluate the proposedmethods in a real-world process automation and control application deployed in an oil refinery and further present a long-term experiment in an office environment. Additionally, we discuss a framework for schedule life-cycle management. [ABSTRACT FROM AUTHOR]

The application of Wireless Sensor Networks (WSNs) in healthcare is dominant and fast growing. In healthcare WSN applications (HWSNs) such as medical emergencies, the network may encounter an unpredictable load which leads to congestion. Congestion problem which is common in any data network including WSN, leads to packet loss, increasing end-to-end delay and excessive energy consumption due to retransmission. In modern wireless biomedical sensor networks, increasing these two parameters for the packets that carry EKG signals may even result in the death of the patient. Furthermore, when congestion occurs, because of the packet loss, packet retransmission increases accordingly. The retransmission directly affects the lifetime of the nodes. In this paper, an Optimized Congestion management protocol is proposed for HWSNs when the patients are stationary. This protocol consists of two stages. In the first stage, a novel Active Queue Management (AQM) scheme is proposed to avoid congestion and provide quality of service (QoS). This scheme uses separate virtual queues on a single physical queue to store the input packets from each child node based on importance and priority of the source's traffic. If the incoming packet is accepted, in the second stage, three mechanisms are used to control congestion. The proposed protocol detects congestion by a three-state machine and virtual queue status; it adjusts the child's sending rate by an optimization function. We compare our proposed protocol with CCF, PCCP and backpressure algorithms using the OPNET simulator. Simulation results show that the proposed protocol is more efficient than CCF, PCCP and backpressure algorithms in terms of packet loss, energy efficiency, end-to-end delay and fairness. [ABSTRACT FROM AUTHOR]

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]

There have been increasing demands for research into multi-channel-based wireless sensor network protocols and applications to support requirements such as increased throughput and real-time or reliable transmission. Researchers or developers of these protocols and applications have to simultaneously analyze the exchanged packets for correctness of both their contents and message exchange timelines. However, if developers were to use multiple conventional single-channel packet sniffers for this purpose, debugging during development and the verification process becomes extremely tedious and difficult because of the need to check the correctness of the protocols over multiple channels individually. Therefore, we present a multi-channel packet-analysis system (MPAS) that helps in debugging and verification for multi-channel protocols or applications. Wireless packets are detected and timestamped by each sniffer module in the MPAS for each channel, and packets are preprocessed and transmitted to a GUI-based analyzer, which then parses the received packets and shows them in order. We present the design and implementation results of the MPAS and evaluate its performance by comparing it against a widely used packet sniffer. [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]

Network mobility (NEMO) enables a group of nodes to connect to the back-end infrastructure during the movement. Because a vehicle must provide passengers good enough transmission quality, various access techniques, for example, 3 G/3.5 G, Wi-Fi or dedicated short range communication, can be simultaneously equipped to aggregate bandwidth and tolerate link failure. This paper extends the Session Initiation Protocol (SIP)-based NEMO framework to support multihoming. First, IEEE 802.21 Media Independent Handover (MIH) is integrated to manage multiple egress interfaces in an on-board unit (OBU). Second, a dynamic synchronization mechanism using the SIP SUBSCRIBE and NOTIFY methods is proposed to manage multiple OBUs in a vehicle. Furthermore, the framework is applied to public transportation systems, for example, bus, train, or mass rapid transit. Passengers may need to transit several times during their journeys. The transit behavior must induce a flood of signaling messages for location update. In this paper, the SIP REFER method is exploited to reduce signaling messages while a group of passengers have scheduled their transit in advance. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In vehicular ad hoc networks (VANETs), themediumaccess control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwardermay experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay. [ABSTRACT FROM AUTHOR]

In this paper we address the problem of radio resource allocation in cooperative relaying networks. We focus on the resource block and power allocations for the downlink of OFDM-based relaying multi-user network. The resource allocation is investigated for both amplify and forward and decode and forward protocols under the constraints of power, resource block pairing and data rate fairness. To reduce complexity, the optimization problem is solved in two steps. In the first step, resource block pairing and allocation are conducted jointly with equal transmission power for both the base station and the relay. In the second step, transmission power is further optimized to maximize the system throughput. Our analysis is focused on the total achievable system throughput and the achievable individual throughput for each user. [ABSTRACT FROM AUTHOR]

Capturing and replaying network flows are important for testing network devices. Replayed traffic should reproduce effects similar to live traffic. This work presents methods to measure the event reproduction ratio, and studies the effectiveness of stateless and stateful traffic replayers based on the events triggered by packets and connections. We use two replayers, SocketReplay and Tcpreplay, and a networking device supporting security services. SocketReplay is a stateful replayer which keeps the state of a connection during replay, while Tcpreplay is a stateless replayer that ignores the connection state. Results indicate that SocketReplay replayed a smaller ratio of the captured traffic and triggered fewer blocking events in subsequent replay tests. Triggering blocking events denotes the replayed traffic cannot fit the onsite context. SocketReplay only replayed 38.74% of the captured TCP traffic, and resulted in an effectiveness of 99.97% (0.00%) in passing (blocking) event ratio. In contrast, Tcpreplay replayed 99.99% of the captured TCP traffic, and resulted in an effectiveness of 99.73% (75.64%) in passing (blocking) event ratio. The choice of a proper replayer and the corresponding replay configuration should depend on the contents of captured traffic and avoid to a significant drop of event reproduction ratio and the effectiveness of replayers. [ABSTRACT FROM AUTHOR]

Cellular network-based machine-to-machine (M2M) communication is fast becoming a market-changing force for a wide spectrum of businesses and applications such as telematics, smart metering, point-of-sale terminals, and home security and automation systems. In this paper, we aim to answer the following important question: Does traffic generated by M2M devices impose new requirements and challenges for cellular network design and management? To answer this question, we take a first look at the characteristics of M2M traffic and compare it to traditional smartphone traffic. We have conducted our measurement analysis using a week-long traffic trace collected from a tier-1 cellular network in the US. We characterize M2M traffic from a wide range of perspectives, including temporal dynamics, device mobility, application usage, and network performance. Our experimental results show that M2M traffic exhibits significantly different patterns than smartphone traffic in multiple aspects. For instance, M2M devices have a much larger ratio of uplink-to-downlink traffic volume, their traffic typically exhibits different diurnal patterns, they are more likely to generate synchronized traffic resulting in bursty aggregate traffic volumes, and are less mobile compared to smartphones. On the other hand, we also find that M2M devices are generally competing with smartphones for network resources in co-located geographical regions. These and other findings suggest that better protocol design, more careful spectrum allocation, and modified pricing schemes may be needed to accommodate the rise of M2M devices. [ABSTRACT FROM AUTHOR]

Handover authentication protocol enables a mobile node to switch from one base station to another without loss or interruption of service when the node exits the transmission area of his or her current base station. This paper proposes a secure prime-order handover authentication protocol based on bilinear pairings. The proposed protocol adapts the concept of pseudonyms to provide user anonymity and user unlinkability. It withstands well-known security threats and achieves mutual authentication, user unlinkability. A batch signature verification mechanism to verify a mass of signatures is presented in our scheme. We also prove that our scheme is secure under random oracle. [ABSTRACT FROM AUTHOR]

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 We propose a protocol to transfer a one-time pad (in a probabilistic manner) from Alice to Bob, over a public channel. The proposed protocol is unique because Bob merely acts as a receiver of the pad (secret key); that is, Bob does not need to send any message back to Alice unless he detects eavesdropping. Such a secure transfer of one-time pad, over public channel, is not possible in classical cryptography, and in quantum cryptography, all previous protocols require Bob to send almost as many messages back to Alice as she does to Bob to establish a key. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Three-party encrypted key exchange (3PEKE) enables two communicating parties to securely exchange confidential and authenticated information over an insecure network via a trusted server. This investigation presents a novel efficient and secure 3PEKE protocol using a super-poly-to-one trapdoor function. The proposed protocol employs the Diffie-Hellman key exchange and adopts the technique that the clients can publicly exchange the factors for generating the session key without the help of the server to reduce the numbers of transmissions. A round-efficient version of the proposed 3PEKE protocol is also described. Compared with related approaches, the proposed protocol not only retains security requirements and possesses lower computational cost but also has fewer transmissions and realizes the lower bounds of communications. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A wireless sensor network generally consists of huge range of inexpensive densely deployed detector nodes that have strictly forced sensing, computation, and communication capabilities. Due to resource restricted detector nodes, it is necessary to scale back the number of data transmission in order that average time period of detector and so the information measure consumption square measure improved. Knowledge aggregation is that the strategy of summarizing and mixing detector knowledge thus on minimizes the number of data transmission within the network. Wireless sensor networks square measure generally deployed in remote and hostile environments to transmit sensitive knowledge, detector nodes square measure in peril of node compromise attacks and security problems like knowledge confidentiality and integrity square measure very necessary. Therefore, wireless sensor network protocols, e.g., knowledge aggregation protocol, need to be designed with security. During this paper we have a tendency to investigate the link between security and knowledge aggregation methodology in wireless detector networks. [ABSTRACT FROM AUTHOR]

Field measurements of signal strength is one of the basic techniques for coverage determination of a cellular network. In this paper, we report on the experimental study of the signal strength measurements in a typical worldwide interoperability for microwave access network operating at 2.62 GHz installed for fixed wireless access in the district of Greater Noida, Uttar Pradesh, India. The experimental data are analyzed for deriving characteristic parameters of the radio propagation environment. The characteristic parameters include path loss exponent and standard deviation of shadow fading. Having derived the characteristic parameters, we propose path loss models for the cellular network. The study also aims at the determination of network coverage for the given system parameters. Results and their analysis are utilized for network planning and optimization of the system parameters for the installed cellular network. [ABSTRACT FROM AUTHOR]

This paper proposes a carrier frequency offset (CFO) estimation scheme for OFDM systems over fast fading channels. In the proposed scheme, exploiting the multiple preambles with the identical values, we estimate the CFO over fast fading channels. In particular, we improve the performance of the CFO estimator by applying the overlapped windows to preambles. Through simulations, we validate the proposed estimation scheme by showing the effectiveness of the proposed estimator. [ABSTRACT FROM AUTHOR]

Currently most existing entity authentication protocols can not guarantee anonymity against compromised verifier in semi-honest model. To solve the question, this paper puts forward a shared certificate entity authentication model, by which some qualities for anonymous entity authentication in semi-honest situation are suggested reasonably. On basis of our proposed model, this paper designs two anonymous entity authentication protocols including an anonymous shared certificate bi-entity authentication protocol and an anonymous shared certificate multi-entity authentication protocol. In proposed protocols it is only single certificate that is used to verify identity correctly and anonymously for legitimate users who has different identity secret. Any compromised verifier has capability to verify correctly whether the user identity is legitimate or not, but it is difficult for it to judge which legitimate user has been verified and distinguish who the verifying user is in particular, therefore attacker does not learn any useful information from legitimate user by spying upon the information of public channel or compromising the certificate. So the security requirements of anonymous entity authentication are achieved successfully, meanwhile the proposed model is more feasibly and effective than zero knowledge protocol in practical applications. [ABSTRACT FROM AUTHOR]

Medium access control overhead is the primary reason for low throughput in wireless networks. Performing blind contentions, contentions without any information of other contenders, and exchanging control message are time-consuming control operations. In this study, we propose a new MAC protocol called distributed sequential access MAC (DSA-MAC) which provides the transmission order without any explicit control operations. It may induce very light control overhead; therefore, compared to existing wireless MAC protocols, DSA-MAC can remarkably enhance network throughput. [ABSTRACT FROM AUTHOR]

Long term evolution (LTE) Advanced is a well designed system that meets the requirements of 4G cellular systems. Its standard specification has been lately released. One of its main features is supporting relaying topology inspired from ad hoc multihop networks. This paper is a survey upon the relaying architecture of LTE Advanced standard based on 3GPP Release 10 specifications. A comparison with other relaying architectures, i.e. IEEE 802.16m and IEEE 802.11s is handled. The originality of this work is in involving comparison with multihop architecture supported by IEEE 802.11s based wireless mesh networks. Several similarities are noted and differences are pointed out. [ABSTRACT FROM AUTHOR]

In this paper, a novel semi-orthogonal distributed Alamouti space-time codes transmission protocol is proposed for a four nodes cooperative communication system consisting of one source, one destination and two semi blind relays over block fading channels. In particular, by semi-orthogonal we mean two orthogonal frequency bands are invoked, one of which is for the transmission by the source node, while the other one is shared simultaneously by the two relay-destination links. Moreover, analytical performances of the proposed semi-orthogonal scheme are investigated in this paper. Specifically, the theoretical expressions of the exact SER and diversity order are presented. Our proposed scheme is capable of achieving higher spectral efficiency and remaining the same diversity order compared to the existing orthogonal one, while attaining better symbol error rate performance and higher diversity order against the non-orthogonal design. Finally, simulation results prove the correctness of the above conclusions and also verify our derivation for the analytical performances. [ABSTRACT FROM AUTHOR]

In this paper, a proposed new wireless protocol so-called wireless controller area network is introduced. WCAN is an adaptation of its wired cousin, controller area network protocol. The proposed WCAN uses token frame scheme in providing channel access to nodes in the system. This token frame method follows the example used in wireless token ring protocol which is a wireless network protocol that reduces the number of retransmissions as a result of collisions. This scheme based on CAN protocol allows nodes to share a common broadcast channel by taking turns in transmitting upon receiving the token frame that circulates around the network for a specified amount of time. The token frame allows nodes to access the network one at a time, giving 'fair' chance to all nodes instead of competing against one another. This method provides high throughput in a bounded latency environment. The proposed WCAN protocol has been developed and simulated by means of QualNet simulator. The performances of this proposed protocol are evaluated from the perspective of throughput, end-to-end delay and packet delivery ratio, and are compared against the IEEE 802.11 protocol. Simulation results show that the proposed WCAN outperforms IEEE 802.11 based protocol by 62.5 % in terms of throughput with increasing network size. Also, it shows an improvement of 6 % compared to IEEE 802.11 standard at a higher data interval rate. [ABSTRACT FROM AUTHOR]

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]

Femtocell is viewed as a promising option for mobile operators to improve coverage and provide high-data-rate services in a cost-effective manner. This paper considers the uplink interference management problem in a spectrum-sharing femtocell network. Assuming that the macrocell base station (MBS) is rewarded for sharing the spectrum with femtocells by setting a reasonable interference cap (IC) for femtocell users’ (FUEs’) transmissions. Within IC, the FUEs allocate their transmission powers competitively while not introducing much interference to both the macrocell users (MUEs) and other FUEs. A Stackelberg game is formulated to jointly maximize the utility of MBS and the individual utility of FUEs. Specifically, the maximum tolerable interference at the MBS is used as the resource that the leader (MBS) and the followers (FUEs) compete for. Then, the backward induction method is applied to achieve the Stackelberg equilibrium and a distributed power update rule is developed for FUEs. In addition, the implementation protocol is presented, some issues related to the implementations and some future extensions regarding the MUEs’ uplink protection are discussed. Lastly, numerical results demonstrate the performance of our proposed power allocation in detail, and show the effects of varying the number of FBSs and changing other system parameters on the system’s performance. [ABSTRACT FROM AUTHOR]

We consider an erasure multi-way relay channel (EMWRC) in which several users share their data through a relay over erasure links. Assuming no feedback channel between the users and the relay, we first identify the challenges for designing a data sharing scheme over an EMWRC. Then, to overcome these challenges, we propose practical low-latency and low-complexity data sharing schemes based on fountain coding. Later, we introduce the notion of end-to-end erasure rate (EEER) and analytically derive it for the proposed schemes. EEER is then used to calculate the achievable rate and transmission overhead of the proposed schemes. Using EEER and computer simulations, the achievable rates and transmission overhead of our proposed schemes are compared with the ones of one-way relaying. This comparison implies that when the number of users and the channel erasure rates are not large, our proposed schemes outperform one-way relaying. We also find an upper bound on the achievable rates of EMWRC and observe that depending on the number of users and channel erasure rates, our proposed solutions can perform very close to this bound. [ABSTRACT FROM AUTHOR]

Voice over Internet Protocol (VoIP) applications based on peer-to-peer (P2P) communications have been experiencing considerable growth in terms of number of users. To overcome filtering policies or protect the privacy of their users, most of these applications implement mechanisms such as protocol obfuscation or payload encryption that avoid the inspection of their traffic, making it difficult to identify its nature. The incapacity to determine the application that is responsible for a certain flow raises challenges for the effective management of the network. In this paper, a new method for the identification of VoIP sessions is presented. The proposed mechanism classifies the flows, in real-time, based on the speech codec used in the session. To make the classification lightweight, the behavioral signatures for each analyzed codec were created using only the lengths of the packets. Unlike most previous approaches, the classifier does not use the lengths of the packets individually. Instead, it explores their level of heterogeneity in real time, using entropy to emphasize such feature. The results of the performance evaluation show that the proposed method is able to identify VoIP sessions accurately and simultaneously recognize the used speech codec. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel medium access control protocol which is based on the IEEE 802.11 distributed coordination function (DCF) and embeds new capability allowing stations to make use of implicit ordering for transmissions. Using them, stations may avoid random access attempts. Implicit ordering is assumed without any control messages and enables contention-free transmissions. We evaluate the performance of the proposed protocol by simulation and show that the proposed protocol outperforms both the legacy DCF and the ideal DCF with respect to the channel utilization. [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]

Wireless sensor networks have found their way to countless applications in many different fields. Due to the restricted power availability these systems are faced with, custom wireless protocols have been designed. Many different protocols have already been conceived, yet each application will impose different requirements. In inertial motion tracking, sensor nodes are applied on the body allowing full body posture reconstruction. These nodes must not hinder or restrict the movements of the user in any way, meaning that a wireless approach is desirable. A suiting protocol that insures robust simultaneous functionality of at least 15 nodes at a rate of 100Hz is required. A TDMA based protocol with master/slave hierarchy is presented for the application at hand. Nodes dynamically decide on their role within the network at startup and reassess the network state regularly. Conflicting situations are handled whenever they arise and nodes react accordingly creating a fully plug-and-play system. Careful implementation of the protocol in embedded software allows data transmission of 19 nodes while each of them consumes an average current of only 3mA. [ABSTRACT FROM AUTHOR]

ABSTRACT Internet Key Exchange (IKE) protocol is widely applied on the Internet to protect confidentiality of the Internet communication. However, there are many high-risk security vulnerabilities in various IKE implementations. Traditional fuzzing approaches with the aim of discovering vulnerabilities have some blind spots, such as time-consuming, low efficiency, and low degree of automation. This paper introduces a new vulnerability discovering approach based on fuzzing and applies the approach to the IKE protocol. Through summarizing the most comprehensive vulnerable points of IKE protocol and proposing a two-stage test cases library, an IKE protocol vulnerability discovering tool called IKEProFuzzer is designed and implemented. It is a network protocol fuzzing framework with extensibility and automated Monitor/Debugger designed by ourselves. In the experiments, IKEProFuzzer has discovered 14 vulnerabilities, including nine released vulnerabilities and five unreleased ones, which affect many kinds of routers and applications. The evaluation results prove the feasibility, efficiency, and extensibility of the approach compared with the existing approaches. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In most existing handshake-based collision avoidance (CA) protocols, nodes in the communication range of the transmitter or the receiver are kept silent during an ongoing communication session (CS). In underwater acoustic communication (UWAC), this restriction results in low throughput and long transmission delay. In this paper, we utilize the long propagation delay in the underwater acoustic channel and the (possible) sparsity of the network topology, and formalize conditions for which a node can transmit even when it is located within the communication range of a node participating in a CS. We consider these conditions as design constraints and present a distributed CA handshake-based protocol, which, by jointly applying spatial and time reuse techniques, greatly improves channel utilization. Our simulation results show that our protocol outperforms existing handshake-based protocols in terms of throughput and transmission delay. These gains come at the price of some reduction in fairness in resource allocation. [ABSTRACT FROM AUTHOR]