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The paper presents an analysis of BSS coloring scheme defined in IEEE 802.11ax standard. The efficiency of dense networks for different scenarios was analyzed and compared. This analysis covers various topologies and work configurations through the use of multiple parameters of the PHY and MAC layers. A positive impact of the coloring mechanism on the QoS was observed. The study also analyzed the impact of the RTS/CTS mechanism on the obtained network performance and adequate prioritization of various traffic classes. It was shown that the proper selection of the coloring mechanism parameters in the IEEE 802.11ax standard has a strong impact on QoS and the performance of dense networks. [ABSTRACT FROM AUTHOR]

The industrial communication market is dominated by Ethernet-based fieldbus systems. Although they share similar requirements and market segments, their implementations and ecosystems differ considerably. As a result, end customers and device manufacturers are faced with a multitude of technologies that need to be produced, run, diagnosed, maintained, and kept in stock. Although the availability of products and services is largely satisfactory, dealing with multiple solutions generates high costs and limits IoT capability. This paper introduces Open Platform Communication Unified Architecture Time-Sensitive Networking (OPC UA TSN) as a new technology and presents the current view. This time, the industrial prospects of fulfilling industrial communication requirements while leveraging the cost benefits of standard Ethernet hardware in the midterm are in reach. We anticipate that OPC UA TSN will reveal itself as a game changer in the field of industrial automation, being a candidate for establishing a holistic communication infrastructure from the sensor to the cloud. [ABSTRACT FROM AUTHOR]

Rate adaptation, which dynamically chooses transmission rate provided at the physical layer according to the current channel conditions, is a fundamental resource management issue in IEEE 802.11 networks with the goal of maximizing the network throughput. Traditional rate adaptation algorithms for IEEE 802.11n networks do not consider the interference problem, which becomes much more serious due to the rapid deployment of IEEE 802.11n devices and large number of mobile terminals. In this paper, an interference-aware rate and channel adaptation scheme RaCA for intensive IEEE 802.11n networks was proposed. Firstly, RaCA leverages RSSI and CSI information together to measure the current channel conditions at the receiver side. RSSI is a coarse-grained indicator and CSI is a fine-grained indicator. Secondly, a two-stage rate adaptation scheme TSRA was designed, which can quickly adapt to optimal bit rate based on RSSI and CSI information. Finally, a quorum-based channel adaptation algorithm QCA was proposed, which does not need control channel. If channel suffers severe interferences, RaCA calls QCA to choose another channel to work on. Simulation and testbed implementation results demonstrate that RaCA achieves significant throughput gain over SampleLite and Minstrel-HT. [ABSTRACT FROM AUTHOR]

The IEEE 802.11ad technology, which allows wireless devices to communicate in the unlicensed 60 GHz ISM band, promisingly provides multi-Gbps data rates for bandwidth-intensive applications. After years of research and development, we are now observing an increasing number of commodity IEEE 802.11ad radios that motivate researchers to exploit the IEEE 801.11ad capability for applications. This work first conducts an empirical study on the IEEE 802.11ad performance. In particular, we characterize the performance of IEEE 802.11ad links considering the variation of network parameters and interference. Secondly, we investigate the possibility of introducing IEEE 802.11ad to an evolving Wi-Fi network. The evaluation results show that our off-the-shelf IEEE 802.11ad hardware can achieve the Gbps level throughput of the transmission control protocol (TCP) and user datagram protocol (UDP). However, the evolvement is not trivial since the hardware can not well maintain the 60 GHz link. The main reason is lacking the fast switchover function between an IEEE 802.11ad and a legacy Wi-Fi link. We then seek the potential of multipath TCP (MPTCP) for the expected switchover. The default MPTCP, which enables data transmissions on both the IEEE 802.11ad and Wi-Fi links, is harmful to the IEEE 802.11ad throughput. Meanwhile, the backup mode of MPTCP, in which the Wi-Fi link acts as a backup for IEEE 802.11ad one, can maintain the comparable performance. Therefore, we propose to adopt MPTCP with the backup mode in the evolving Wi-Fi networks. The efficiency of MPTCP-based switchover is confirmed by conducting real experiments. [ABSTRACT FROM AUTHOR]

IEEE 802.15.5 standard introduces the mesh routing which improves reliability and robustness of routing in wireless sensor network since there are multiple routes from source node to destination node. To achieve energy efficiency for a long network lifetime, the asynchronous energy saving is proposed in IEEE 802.15.5, which includes the receiver-initiated unicast mechanism and the sender-initiated broadcast mechanism. In this article, an improved asynchronous energy saving named semi-synchronous energy saving is proposed to deal with the energy inefficiency from idle listening existing in asynchronous energy saving. In semi-synchronous energy saving, every node maintains the wake/sleep schedule information of nodes in its two-hop neighborhood and uses this information to calculate the wake-up time of an interested neighbor that the data will be sent to, which reduces idle listening time in both unicast and broadcast mechanisms. A low delay routing mechanism is also proposed based on the wake/sleep schedule information of neighbors. Furthermore, the optimal guard time to guarantee receiving the wake-up notification from neighbor in the presence of clock drift is investigated for saving energy. The performance analysis and simulation evaluation show that semisynchronous energy saving saves more than 80% of energy with less than 30% memory cost compared to asynchronous energy saving, and it also improves the time of completing broadcast and the end-to-end delay. [ABSTRACT FROM AUTHOR]

The Time-Slotted Channel Hopping (TSCH) mode for medium access control (MAC) included in the standard IEEE 802.15.4 has been designed as the multichannel MAC protocol for Low-power and lossy networks (LLNs), a key component of the Internet of Things (IoT). Its flexibility makes the TSCH mode a very promising candidate for the future of the MAC layer in LLNs. As such, its performance under different conditions must be assessed, so that accurate guidelines for its application can be drawn. In this paper, we present an experimental evaluation of the protocol based on simulations on ContikiOS Java Simulator (COOJA). The experimental setup is based on the 6TiSCH architecture for LLNs. Results show that TSCH performs better under conditions of medium traffic load than under low or high traffic load. [ABSTRACT FROM AUTHOR]

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle's safety. During the SCH interval, the non-safety massages are transmitted. An analytical model is proposed in this paper to evaluate performance, reliability and efficiency of the IEEE 802.11p and IEEE 1609.4 protocols. The proposed model improves the existing work by taking serval aspects and the character of multichannel switching into design consideration. Extensive performance evaluations based on analysis and simulation help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the IEEE 802.11p and IEEE 1609.4 protocols, and enhancement suggestions are given. [ABSTRACT FROM AUTHOR]

Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems. Considering fairness, quality of service and minimum interference for customer-premises-equipment, we also develop a greedy algorithm for channel allocation and a non-cooperative game-theoretic framework for near-optimal power allocation. The base stations of networks are treated as players in a game, where they try to increase spectrum utilization by controlling power and reaching a Nash equilibrium point. We further develop a utility function for the game to increase the data rate by minimizing the transmission power and, subsequently, the interference from neighboring networks. A theoretical proof of the uniqueness and existence of the Nash equilibrium has been presented. Performance improvements in terms of data-rate with a degree of fairness compared to a cooperative branch-and-bound-based algorithm and a non-cooperative greedy approach have been shown through simulation studies. [ABSTRACT FROM AUTHOR]

In the presence of distributed generators (DGs) the fault current sensed by relay in the forward direction is larger than that in the reverse direction. Thus, it is required to have different relay settings for both forward and reverse directions. This paper investigates the impact of DG controller operating modes on the coordination of conventional and dual setting overcurrent relays (OCRs). The different DG control modes are voltage control mode (VCM) and current control mode (CCM). A comparative study of protection coordination is presented in both the operating modes of the DG. This scheme is tested on a 3-bus meshed system and the IEEE 34-node distribution system in which an electronically interfaced DG is connected. The protection coordination problem is formulated as a nonlinear programming problem and the optimal settings of OCRs are determined by using a genetic algorithm. [ABSTRACT FROM AUTHOR]

This paper presents a new algorithm based on the sequential method for power flow calculation in multiterminal AC/DC systems. The proposed approach differs from other similar studies in the literature by handling two main properties. Firstly, a real equivalent circuit model is considered for the under-load tap changer transformers (ULTCs) of DC converters for the first time in the literature. Hence, new DC equations are obtained. Thus, exact and accurate results can be obtained for practical applications using the proposed algorithm. Tap values adjustment effects of the ULTCs connected to DC converters are included into the Jacobian matrix instead of the bus admittance matrix in the sequential AC power flow algorithm, as well as other ULTCs in the AC system. For this aim, new equations for calculating power and Jacobian matrix elements are obtained. Secondly, more than one independent multiterminal DC subsystem in terms of DC connection is included in the study. DC power ow calculation is performed for each DC subsystem independently in the algorithm. Thus, modularity and exibility are provided for including or removing any DC subsystems without needing to change the proposed algorithm. The proposed approach has been tested on a modified IEEE 20-bus AC/DC test system. The proposed AC/DC power ow algorithm was written and performed in MATLAB. The results show that the proposed approach is accurate and reliable in convergence. [ABSTRACT FROM AUTHOR]

One of looped networks that in recent years has been much noticed is standard known as IEEE 802.17 RPR ring network or the return packet. Architecture RPR ring network protocol that transmits data between nodes connected in a double ring structure to support. RPR has two single transit buffer structure (STB) and double transit buffer (DTB), respectively. Single transit buffer architecture, just a high-priority traffic buffering (HP) and low priority (LP) passing through the ring buffer architecture serves and double, two separate buffer for high-priority and low priority traffic is considered passing. Send information for scheduling algorithms used in network nodes RPR, queue priority (Priority-Queue), respectively. In this way, the separation of traffic based on priority and high priority traffic has absolute priority over lower priority traffic so that always the highest priority to transit buffer appropriated therefore of high priority traffic such as video packet, the nodes access to congested suffered numerous delays and instability vibration are ring (Jitter). In this thesis addition to scheduling priority queue, plans, schedules DRR and DRR + to increase the quality of service to traffic with high priority on congested node in a network with a ring structure with 10 nodes software Opnet simulation and the performance timing of passing information about at least two network nodes in the hub scenario (hUB) in which all the nodes transmit information to a node with video traffic conditions, congestion were examined happened and qualitative results were compared to that, the display shows the relative improvements in reducing delays and instability shaking changes in the timing of DRR and DRR + compared to the recommended standard. [ABSTRACT FROM AUTHOR]

The IEEE 802.15.6 was established in Feb 2012 due to emergency of wireless body area networks (WBANs). In order to improve the performance of WBANs, the physical (PHY) layer, medium access control (MAC) layer and network layer have been discussed in a number of literatures. Although there are also many previous works on performance analysis for WBANs, a noise free was frequently assumed when contention error is taken into account in MAC layer. It means that in these works bit error rates (BERs) were not taken into consideration adequately. In this paper, we propose the Markov chain Monte Carlo (MCMC) method to analyze performance in the PHY and MAC layers for WBANs, in which BERs are taken into consideration. The BERs are theoretically analyzed depending on different Bose-Chaudhuri-Hocquenghem (BCH) code rates, and then the BCH code rate for every sensor node is optimized in sense of the highest throughput while assuming the signal to noise ratio (SNR) of every sensor node is different. Furthermore, the dependence of throughput on the BER is clearly explained by calculating the access probability for every sensor node in large SNR region. The BCH code was adopted as an example and then adaptive BCH code rates for WBANs were proposed. The application of proposal method to other error correcting codes is straightforward. [ABSTRACT FROM AUTHOR]

The performance of an IEEE 802.11 wireless local area network is highly dependent on how the stations (STAs) are associated with the access points (APs). Frequency channels are assigned to the APs satisfying the interference constraints among them. As the number of non-overlapping frequency channels are limited, all APs in a given area may not be activated simultaneously because of mutual co-channel interference. The major concern of this paper is to select an appropriate subset of APs together with their frequency assignment as well as to find out an efficient association between the STAs and APs that maximizes the aggregate throughput of the network. We argue that, the two-step solution of the problem may become a suboptimal solution whereas ignoring the interference may cause a significant overestimation of the performance. Motivated by these, we propose an integrated model based on integer programming and an efficient greedy algorithm that address both aspects simultaneously. The performance of the proposed approach is analyzed for different utility functions and association policies. We have shown that the proposed approach outperforms some existing approaches and takes care of load balancing across the APs as well as fairness in throughput obtained by the STAs. Moreover the approach is robust enough to support user mobility and able to manage external interference. [ABSTRACT FROM AUTHOR]

In this paper, a novel reference generation method based on Improved Synchronous Reference Frame (ISRF) is presented for Dynamic Voltage Restorer (DVR). This method is applicable for both single phase and three phase systems in order to compensate unbalanced voltage sag/swell and unbalanced voltage harmonics at the same time. To reduce the drawbacks of Conventional SRF and Symmetrical components based SRF (SCSRF), ISRF is proposed in this paper for compensation of unbalanced voltage sag/swell and harmonics. In this paper, the compensation of 50% voltage sag and 25% voltage swell is performed in addition to unbalanced voltage harmonics. Performance results of proposed method show good robustness and faster detection for balanced/unbalanced voltage sag/swell/harmonics compared with SCSRF. By the proposed method, total harmonic distortion is reduced to values which are fairly less than the limits defined in IEEE 519 Standards. [ABSTRACT FROM AUTHOR]

IEEE 802.11p is an amendment to the IEEE 802.11 standard for Wireless Access in Vehicular Environments (WAVE). Lower layer wireless transmission formats and protocols are defined for both vehicle-to-infrastructure and vehicle-to-vehicle communication links to support cooperative intelligent transport systems. The medium access control (MAC) layer uses carrier sensing as a means for detecting the busy state of the radio channel before transmitting. In heavily loaded vehicular ad hoc networks (VANETs), the channel access delay, when attempting to access the channel, unpredictably increases when it is sensed as busy. The European Telecommunications Standards Institute (ETSI) defines safety-related messages. These messages require a dependable behavior of the communication link. In this context, dependable behavior translates to the reliable delivery of data packets within a specified deadline regardless of changes in traffic density. Unfortunately, the WAVE amendment does not fulfill the requirements for such dependable behavior. This contribution reports on performance evaluations by simulation studies of the WAVE MAC and the decentralized congestion control (DCC) mechanism specified by the ETSI in addition to the existing enhanced distributed channel access. The simulation scenario under study is a two-VANET-merging highway situation. The MAC protocol has to adapt to variable traffic densities in this scenario. The performance is evaluated in terms of coverage range and MAC-to-MAC delay reliability and DCC state stability. Furthermore, a novel performance indicator is defined, evaluated, and discussed, which the authors of this work have named data novelty. Finally, a multistate-active DCC mechanism is proposed, which achieves a dependable behavior. [ABSTRACT FROM PUBLISHER]

This study presents a practical assessment of the recent IEEE 802.15.3c statistical model aimed at the characterisation of 60 GHz indoor radio channels, for high-definition (HD) video streaming, envisaging tele-health applications. A simple ray-tracing model was developed to characterise the 60 GHz propagation channel and to compare it with the recent IEEE standard, in an indoor scenario mimicking a surgical room. Additionally, a measurement campaign was carried out to validate those model approaches and subsequently analyse the propagation path loss and time dispersion parameters of the propagation channel in the typical usage scenarios. Finally, the severity of multipath effects on the key performance indicators of HD video transmission, under line-ofsight (LOS) and non-LOS situations, were evaluated. [ABSTRACT FROM AUTHOR]

Many people, especially technology historians, often ponder "Where would the world be without Ethernet?" Now, such a rhetorical question typically has no answer because you cannot rewind time, remove Ethernet from being invented, and let time fast forward to the present day. However, we have many active contributors amongst us who have been part of that history as it has evolved over the past 30 years. The Evolution of Ethernet Standards in 802.3 Working Group covers great details on the history of not just Ethernet standards development, but many dot standards that have led to support of wide-ranging applications. For me, just the first sentence captures the past, the present, and the future that I'd like to know more about: Ethernet is constantly evolving, adapting to the needs of the networking world, addressing the requirements of both operators and end-users, while making sure that the resulting technology is cost-efficient, reliable, and operates in a plug and play manner. [ABSTRACT FROM AUTHOR]

Orthogonal frequency division multiplexing (OFDM) is a special case of multicarrier transmission where a single DataStream is transmitted over a number of lower rate subcarriers. In July 1998, the IEEE standardization group decided to select OFDM as the basis for their new 5-GHz standard aiming a range of data stream from 6 up to 54 Mbps. This new standard is the first one to use OFDM in packet-based communications. In wireless communication, concept of parallel transmission of symbols is used to achieve high throughput and better transmission quality. Orthogonal Frequency Division Multiplexing (OFDM) is one of the techniques for parallel transmission. The idea of OFDM is to split the total transmission bandwidth into a number of orthogonal subcarriers in order to transmit the symbols using these subcarriers in parallel. In this paper we will discuss the basics of OFDM technique, role of OFDM in this era, its benefits and losses and also some of its application. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the cost-effectiveness of a Wi-Fi solution for vehicular Internet access. We define the cost-effectiveness as the cost saving by deploying and operating a low-cost Wi-Fi infrastructure instead of a costly benchmark cellular network. To characterize the service quality of Wi-Fi deployment, we also define the normalized service delay (NSD), which is the service time to fulfill a data application via the Wi-Fi network normalized by that via the cellular network. To derive the service time, we analyze the average throughput capacity of a generic vehicle in the Wi-Fi network and the average downlink capacity in the cellular network. In particular, we propose deploying Wi-Fi access point (AP) at signalized intersection and study the fundamental influence of traffic signals (which yield an interrupted vehicle traffic) on Wi-Fi access. Then, we examine the tradeoff between cost-effectiveness and NSD by identifying interplays between controllable (e.g., the density of Wi-Fi deployment and user's satisfaction) and uncontrollable parameters (e.g., vehicle traffic statistics). Our results are very useful for network operators to make strategic planning of Wi-Fi deployment for vehicular Internet Access. [ABSTRACT FROM AUTHOR]

In this paper, we consider the multi-hop communications in contention period of medium access control protocol over millimeter-wave band. A relaying devices selection policy and a grouping algorithm are proposed, and the directional carrier sense multiple access/collision avoidance protocol in the immediate acknowledgement mode for IEEE 802.15.3c is considered under saturation environments. The purpose of this paper is to analyze the effect of using directional antennas and relaying devices in contention period. A sensing region and an exclusive region are computed probabilistically and used in the grouping algorithm. Numerical results show that the narrower radiation beamwidth allows to use a channel more spatially, and the effect of using relaying devices increases as the beamwidth and number of devices increase. Those effects are presented in the throughput and average delay. The obtained results will be used as performance criterion for the multi-hop communications in millimeter-wave wireless personal area networks. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, we propose a simple theoretical model to compute the maximum spatial reuse feasible in a VANET. We focus on the ad hoc mode of the IEEE 802.11p standard. Our model offers simple and closed-form formulas on the maximum number of simultaneous transmitters, and on the distribution of the distance between them. It leads to an accurate upper bound on the maximum capacity. In order to validate our approach, results from the analytical models are compared to simulations performed with the network simulator NS-3. We take into account different traffic distributions (traffic of vehicles), and study the impact of this traffic on capacity. An application of this work is the parameterization of the CSMA/CA mechanism. Such an optimization is developed at the end of this paper. [ABSTRACT FROM AUTHOR]

In this paper we consider the analysis of an $$M/D^{[y]}/1$$ vacation queue with periodically gated discipline. The motivation of introducing the new periodically gated discipline lies in modeling a kind of contention-based bandwidth reservation mechanism applied in wireless networks. The analysis approach applied here consists of two steps and it is based on appropriately chosen characteristic epochs of the system. We provide approximate expressions for the probability-generating function of the number of customers at arbitrary epoch as well as for the Laplace-Stieljes transform and for the mean of the steady-state waiting time. Several numerical examples are also provided. In the second part of the paper we discuss how to apply the periodically gated vacation model to the non real-time uplink traffic in IEEE 802.16-based wireless broadband networks. [ABSTRACT FROM AUTHOR]

This paper considers the contribution of independent owners (IOs) operating within microgrids (MGs) toward green power generation in deregulated energy markets. An optimization scheme is introduced for sizing distributed renewable generation (DRG) and a distributed energy storage system (DESS) based on a novel energy management system (EMS) that accounts for demand response (DR), DESS dispatch and performance degradation, dynamic pricing environments, power distribution loss and irregular renewable generation. The proposed EMS utilizes an iterative Newton-Raphson linear programming algorithm that schedules resources in order to minimize the objective function, to deal with the complicated nonlinear nature of the problem and to enable efficient long-term assessments. The EMS is used to evaluate candidate solutions that are generated by a genetic algorithm (GA) to determine the optimal combination of DRG and DESS. A case study for IEEE 34-bus distribution MG in Okinawa, Japan, is used for testing the algorithm and analyzing the potential for IO/MG investments and their strategies. [ABSTRACT FROM AUTHOR]

In heterogeneous networks, network selection by nature is a multidimensional problem. Many parameters need to be considered for handover decision making. Apart from handover accuracy and efficiency, an important consideration is the scalability and signaling overhead of such handover algorithms. In this article we propose to break down a Simple Additive Weighting (SAW) based heterogeneous handover algorithm in two parts. The execution of the first part is carried out in an independent and proactive manner prior to the actual handover, assuming three different handover architectures. The handover architectures are differentiated based upon the level of the distribution of the handover algorithm among multiple network components. The Media Independent Handover (MIH) and its different services are used to retrieve and share information among MIH enabled nodes and for conformity among heterogeneous network standards. The proposed algorithm is evaluated with respect to handover accuracy, handover delay efficiency and signaling overhead. The evaluation is carried out for all three handover architectures using simulations. Only handovers between Wi-Fi (IEEE 802.11) and WiMAX (IEEE 802.10) networks are considered. But the handover framework is general and can be extended to consider other wireless and mobile communication networks. [ABSTRACT FROM AUTHOR]

Presents the list of reviewers who contributed to in IEEE Transactions on Instrumentation and Measurement 2015. [ABSTRACT FROM PUBLISHER]

This paper presents the development of a data acquisition system and the evaluation of the electromagnetic phenomena associated with power quality according to the IEEE Standard 1159-1992 and applied to the particular case of single-phase electrical power systems. The evaluation software is implemented in the Labview® professional software using a NI 6009 USB board of the National Instrument® as acquisition device. The hardware implementation of the sensors was shown. Also the development of the algorithm and the design of a graphical user interface for viewing of the voltage and current waveforms, spectra, frequency and the power quality disturbances such as sags, swells, undervoltage, overvoltage, so on. Likewise, at the end a concise analysis of costs is presented to show that the developed system has a lower price to current solutions that are available in the market. Finally a study case was shown. [ABSTRACT FROM AUTHOR]

This paper examines the bibliometric analysis of 3442 papers published in the journal IEEE Transactions on Antennas and Propagation during the period 2010-2014. The data was taken from the archives of the journal available in printed and online form. The study focuses on the articles published with respect to year-wise growth of the articles published, authorship pattern, collaborative measures like collaborative index, degree of collaboration, collaborative coefficient, modified collaborative coefficient, subject-wise distribution of articles, contribution of Indian authors, contribution of each country based on authors' nationality, number of references in each issue, year-wise references and citation analysis on the articles published in this journal during the above period. Finally, contribution of Indian authors during these five years is also highlighted. [ABSTRACT FROM AUTHOR]

The IEEE 802.15.6 standard is introduced to satisfy all the requirements for monitoring systems operating in, on, or around the human body. In this paper, analytical models are developed for evaluating the performance of the IEEE 802.15.6 CSMA/CA-based medium access control protocol for wireless body area networks (WBAN) under unsaturation condition. We employ a three-dimensional Markov chain to model the backoff procedure, and an M/G/1/K queuing system to describe the packet queues in the buffer. The throughput and delay performances of WBAN operating in the beacon mode are analyzed in heterogeneous network comprised of different user priorities. Simulation results are included to demonstrate the accuracy of the proposed analytical model. [ABSTRACT FROM AUTHOR]

In this paper, we propose a simple and effective way to improve the quality of service (QoS) of uplink resource allocation for the extended-real-time polling service (ertPS) in IEEE 802.16e broadband wireless networks. The primitive ertPS algorithm determines the amount of resources allocated to a given subscriber station only according to the requested volume in current polling cycles regardless of the knowledge of demand trend. This trend is continuously increasing or declining, which may be incomplete to truly reflect reasonable resource allocation for subscriber stations in different demand tendencies. To cope with this problem, we developed a context-aware ertPS algorithm which gathers statistics on the numbers of request headers of medium access control layer management messages among various subscriber stations, and thus uses the statistical information to enable a dynamic allocation of additional uplink resources to subscriber stations with continuously increasing bandwidth demands. The simulation results show that in comparison with the original ertPS algorithm, the proposed context-aware resource allocation scheme is effective to increase the data throughput as well as to decrease the packet loss rate and packet delay so that the user-perceived QoS can be improved. [ABSTRACT FROM AUTHOR]

A 50 MHz-1 GHz low-noise amplifier circuit with high linearity for IEEE 802.22 wireless regional area network is presented. It was implemented without any inductor and offers a differential output for balun use. Noise canceling and linearity boosting techniques were combined to improve the amplifier performance in such a way that they can be separately optimized. Linearity was improved using diode-connected transistors. The amplifier was implemented in a 130 nm CMOS process in a compact 136 μm × 71 μm area. Simulations are presented for post-layout schematics for two classes of design: one for best linearity, another for best noise figure (NF). When optimized for best linearity, simulation results achieve a voltage gain >23.7 dB (power gain >19.1 dB), a NF <3.6 dB over the entire band (with 2.4 dB min figure), an input third-order intercept point (IIP3) >3.3 dBm (7.6 dBm max.) and an input power reflection coefficient S <−16 dB. When optimized for best NF, it achieves a voltage gain >24.7 dB (power gain >19.8 dB), a NF <2 dB over the entire band, an IIP3 >−0.3 dBm and an S <−11 dB. Monte Carlo simulation results confirm low sensitivity to process variations. Also a low sensitivity to temperature within the range −55 to 125 °C was observed for Gain, NF and S11. Power consumption is 18 mW under a 1.2 V supply. [ABSTRACT FROM AUTHOR]

???This paper presents a critical analysis of ultrawideband (UWB) and considers the turbulent journey it has had from the Federal Communications Commission?€™s bandwidth allocation in 2002 to today. It analyzes the standards, the standoffs, and the stalemate in standardization activities and investigates the past and present research and commercial activities in realizing the UWB dream. In this paper, statistical evidence is presented to depict UWB?€™s changing fortunes and is utilized as an indicator of future prominence. This paper reviews some of the opinions and remarks from commentators and analyzes predictions that were made. Finally, it presents possible ways forward to reignite the high-data-rate UWB standardization pursuit. [ABSTRACT FROM PUBLISHER]

This paper presents a novel probabilistic framework for solving the security constrained generation dispatch problem in the presence of wind power and responsive loads. The proposed framework is capable of decreasing the probability or preventing any constraint violations in real time for different combinations of uncertain variables while minimizing the desired objective functions. The presented framework is formulated as a chance constrained problem using the point estimate method to calculate the probabilistic characteristics of output variables. The objective functions which are studied in this work are total operation costs, emissions, and security indexes. Also a probabilistic multi-objective framework is developed to optimize all objective functions concurrently. To study the effect of responsive loads, two different cases are studied neglecting and regarding demand response resources. The proposed method is studied on the IEEE 30-bus system and the results are presented and compared with results obtained from the deterministic generation dispatch framework. [ABSTRACT FROM AUTHOR]

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Ad hoc networks have been proposed for emergency communication wherein the required infrastructure is unavailable. However, a major concern in Ad hoc networks is collisions. Even in infrastructure based wireless networks, when the number of contending nodes is high, more number of frame collisions occur which leads to drastic reduction in network performance. In all IEEE 802.11 based wireless and Ad hoc networks, the backoff algorithm dynamically controls the contention window of the nodes experiencing collisions. Even though several algorithms such as Binary Exponential Backoff, Double Increment Double Decrement backoff, Exponential Increase Exponential Decrease backoff, Hybrid Backoff, Binary Negative Exponential Backoff etc. have been proposed in the literature to enhance the performance of IEEE 802.11 Distributed Coordination Function (DCF) protocol, most of them have not been developed for real- traffic scenarios. Also the packet collision rate is high using these algorithms. So, in this paper, a new Contention Window based Multiplicative Increase Decrease Backoff (CWMIDB) algorithm is proposed for the DCF protocol to alleviate the number of collisions. Furthermore, the packet transmission procedure of the DCF protocol is modified to avoid channel capture effect and this is represented with a Markov chain model. A simple mathematical model is developed for transmission probability considering the non-saturated traffic and channel errors. Results show that the proposed CWMIDB algorithm provides superior quality-of-service parameters over existing backoff algorithms. [ABSTRACT FROM AUTHOR]

Multicast communication is an important service in wireless mesh networks (WMNs). It covers a broad range of applications, including data distribution, video conferencing, and distance learning. In this paper, we discuss the issue of bandwidth guaranteed multicast routing in multi-channel multi-radio WMNs. The problem of our concern is to construct a tree per multicast session such that the cost of the system, which is defined as the amount of total consumed bandwidth, is minimized. In order to solve the problem efficiently, we design Bandwidth Guaranteed Minimum Cost Tree construction (BGMCT) algorithm. Our algorithm yields cost-effective solutions as it exploits the wireless broadcast advantage (WBA) property of the wireless medium. In the proposed algorithm, we have developed two strategies for constructing minimum cost trees. Firstly, the number of the relay nodes in each tree is minimized. Secondly, the amount of overlapping between the shortest paths which connect different destinations of each session to its source node, is taken into account. The simulation results demonstrate that our algorithm outperforms existing solutions. Moreover, BGMCT provides near to optimal outcomes in a reasonable time. [ABSTRACT FROM AUTHOR]

The exchange of vital sign data between legacy healthcare devices and application hosting devices requires interoperability and has become a critical issue for telecare monitoring systems. This study proposes an ISO/IEEE 11073 personal health device (x73-PHD) system that enables legacy healthcare devices to transmit vital sign data to an application-hosting device on a network. The proposed architecture is composed of the x73-PHD gateway, x73-PHD adapter, and legacy healthcare devices. Using a firmware upgrade mechanism provided by the system, the adapter connects legacy healthcare devices to transmit vital sign data to the application-hosting device, based on international x73-PHD standards and the interoperable platform. The proposed solution overcomes the problems of existing legacy healthcare device support and interoperability for personal healthcare systems. This system will enable legacy healthcare devices to link with a standard platform and supports telecare promotion. [ABSTRACT FROM AUTHOR]

With the ratification of the IEEE 802.11ad amendment to the 802.11 standard in December 2012, a major step has been taken to bring consumer wireless communication to the millimeter wave band. However, multi-gigabit-per-second throughput and small interference footprint come at the price of adverse signal propagation characteristics, and require a fundamental rethinking of Wi-Fi communication principles. This article describes the design assumptions taken into consideration for the IEEE 802.11ad standard and the novel techniques defined to overcome the challenges of mm-Wave communication. In particular, we study the transition from omnidirectional to highly directional communication and its impact on the design of IEEE 802.11ad. [ABSTRACT FROM PUBLISHER]

In this paper, we analytically study the dense basic service set network transmission problems in very high throughput (VHT, namely IEEE 802.11ac) wireless local area networks (WLANs) due to nervous bandwidth resources. Our contributions are threefold as follows. Firstly, we derive the closed-form expressions of throughput gains for primary channel establishment from multi-band selection using the optimal skipping rule, which balances the throughput gain from finding a good quality band with the overhead of measuring multiple bands. Secondly, in order to satisfy the quality of service of overlapping BSS users, we design a space interference avoidance mechanism, which can improve the system throughput for the whole dense WLANs. Thirdly, in order to further improve the transmission performance of dense BSS networks, we propose an unequal bandwidth transmission mechanism based on the VHT WLANs, which can not only clear the redundant network allocation vector duration timely but also use the limited bandwidth efficiently. The proposed protocols and mechanisms exploit both time and frequency diversity sufficiently, and are shown to result in typical throughput gains compared with the traditional IEEE 802.11 MAC protocol. [ABSTRACT FROM AUTHOR]

Node replication attack possess a higher level of threat in wireless sensor networks. A replicated node takes advantage of having legal identity of the compromised node to control the network traffic and inject malicious information into the network. Several techniques have been proposed to detect node replication in wireless sensor networks. However, in most of these techniques, the responsibility for replica detection lies either with the base station or a few randomly selected witness nodes. In this paper, we propose a technique for detecting replicas without the participation of base station and witness nodes. In the proposed scheme, each node is assigned with a color (value), which is unique within its neighborhood. A color conflict within the neighborhood of a node is detected as a replica. We made a comparison of the proposed scheme with RED (Conti et al. in IEEE Trans Dependable Secure Comput 8(5):685-698, ), LSM (Parno et al. in Proceedings of IEEE symposium on security and privacy. IEEE, pp 49-63, ), and SET (Choi et al. in Proceedings of third international conference on security and privacy in communications networks and the workshops, SecureComm 2007. IEEE, pp 341-350, ). Parameters considered for comparison are detection probability, communication complexity and storage overhead. We observed that the proposed scheme has a higher detection probability, and lower communication and storage overhead. [ABSTRACT FROM AUTHOR]

IEEE 802.16e standard have been designed for both delay sensitive and delay tolerant applications. This paper presents energy-saving strategies by extending unavailability interval for multiple power saving classes simultaneously. The proposed model allows mobile stations to dynamically adopt multiple sleep mode operation or multiple partial sleep mode operation based on the buffer status of power saving class I and II. We set up partial sleep interrupt function which decides whether to stay in multiple partial sleep state or busy state to enhance the response time in real time traffic. Various performance indices of the system are presented. A cost model is formulated to determine the optimal values of various parameters at minimum cost using quadratic fit search method. It is shown numerically that the proposed model improves the system performance efficiently. [ABSTRACT FROM AUTHOR]

Requirement engineering is a disciplined application of proven principles, methods, tools and notations to describe the behavior of a system. Generally a project suffers because of improper determination and documentation of software requirements. The intricacies in software development processes are often not understood by the client. Hence, requirements submitted by client need a careful examination. In order to produce proper artifact, it is necessary that the software requirements should be documented into the software requirement specification (SRS) on the basis of the recommendations of IEEE 830:1998 document. To address these issues, a measure for early estimation of software complexity based on SRS of the yet to be developed software is proposed. Further, this complexity measure serves as a basis for computing and deriving early estimation of software development effort too. The results obtained from the proposed measure are able to establish that the measure is accurate and precise as compared to various other existing measures that are based on the algorithm/parameters, software code, function point analysis and use case points. All this is accomplished using SRS document at an early phase of software development process. The proposed measure is robust, comprehensive, early alarming and compares well with other development effort estimation measures proposed in the past. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel cooperation strategy for coherent Impulse-Radio Ultra-Wideband (IR-UWB) communication systems with one relay. While non-orthogonal cooperation in narrow-band wireless networks often requires deploying distributed space-time codes with joint encoding of several symbols at the source and relays and joint decoding of these symbols at the destination, the proposed non-orthogonal cooperation scheme constitutes the first known symbol-by-symbol-based scheme where cooperation is entirely realized within one symbol duration. This follows from the fact that the proposed strategy is adapted to the structure of the Pulse Position Modulation (PPM) that constitutes the most popular modulation scheme associated with UWB transmissions. We also propose a simple and efficient power allocation strategy that further boosts the performance of the proposed cooperation strategy. The error performance of the proposed scheme is evaluated analytically while simulations performed over the IEEE 802.15.3a UWB channel model are provided to support the theoretical results. [ABSTRACT FROM PUBLISHER]

Wireless Regional Area Network is a standard named IEEE 802.22 Working Group purposed in Nov 2004. The task was to develop an air interface (i.e., PHY and MAC) based on CRs for unlicensed operation in the TV broadcast bands. For this the cognitive radio techniques are of primary importance in order to sense and measure the spectrum and detect the presence/absence of incumbent signals. There are various sensing methods to avoid the inference with the licensed users. In this paper various sensing techniques are considered and by comparing we find out which one is best suitable in WRANs [ABSTRACT FROM AUTHOR]

Rooftop solar panels and solar farms has become popular as a means of generating green and emission free electric energy. A standalone Microgrid is fully controlled by sophisticated controlling scheme and ready to contribute to utility grid. A standalone solar Microgrid is an economic solution in residential area as well in far off location. It consists of PV panels, DC/DC converters, storage blocks, MPPT controller, Inverter, main controller and loads. A standalone PV system has two stages design. In power stage, all components will properly be sized to supply demand loads. Control stage contains all controllers to meet the predefined requirements. There is plenty of research on each individual element; however, for system integrator there are only a few studies which have considered the whole system. This study tries to show a systematic step design for Photovoltaic-based (PV) Microgrid. All power and control design stages will be discussed. IEEE standards and recommendation for standalone PV grid and storage banks (batteries) are used as guideline. [ABSTRACT FROM AUTHOR]

IEEE 1451 standard has been proposed to provide a common communication interface and transducer electric data sheet format for wired and wireless distributed applications in smart transducers (sensors and actuators). Currently, a unified Web service for IEEE 1451 smart transducers is a must. However, ensuring the security of web-services-based communications for IEEE 1451 smart transducers is an unsolved problem. In this paper, we proposed a cross-layer security mechanism that deals with the requirements of authentication, integrity, confidentiality, and availability across the communication process in IEEE 1451 smart transducers. The scheme contains three cross-layer components logically, including XML Encryption and Signature, SOAP Security Extension, and Web Services Description Language (WSDL) Security Checking. The former two components satisfy the requirements of confidentiality, availability, integrity, authentication, nonrepudiation, and freshness. The third component satisfies the requirement of availability, which can protect the system against denial-of-service (DoS) attack. The three cross-layer security components are integrated seamlessly in our scheme. To evaluate the overhead, we perform tests to evaluate the effect of message size on the performance of the access inquiry web service. The result supports the usefulness and feasibility of our scheme. [ABSTRACT FROM AUTHOR]