In order to support anywhere and anytime services of Beyond 4G networks, new deployment solutions will be required that can cost-effectively address the capacity demand of the future and also offer consistently high bit rates and decent quality of service throughout the network coverage area. In this article we look into an advanced outdoor distributed antenna system (DAS) concept, dynamic DA…
Active safety systems such as anticollision radar play a major role in reducing traffic accidents. The principal task of the radar is to detect the presence of targets and estimate their positions. To make this task, the system called coded anticollision radar use a code at transmission and correlation at reception. The actual used codes are the BPRS sequences but they are not sufficient to sha…
In conventional multiple-input multiple- systems, each antenna is connected to a radio-frequency (RF) chain. Due to the tiny wavelength of millimeter waves (mmWave), tens of antennas can be packed into a small area in mmWave transceivers. However, implementing an RF chain for each antenna is impractical due to the high cost and power of mixed-signal devices. In order to reduce the cost and ge…
The draft document of the new IEEE 802.15.4e specification assumes receiver initiated transmission (RIT) to reduce energy consumption of wireless sensors by turning off the radio periodically, even if they operate in mesh topology. The original contribution from this paper is developing and evaluating the RIT strategies intended for street lighting systems using wireless sensor networks to cont…
Pre-registration as an important feature in FIMPv6, ensures providing the continuous mobility services for the end-users roaming across heterogeneous wireless networks, and is achieved by obtaining the timely and precise link layer (L2) trigger in the handover preparation. Firing the L2 trigger in the timely manner for deterministic handovers hence is crucial for guaranteeing the handover perfo…
High performance of MIMO-OFDM wireless systems is very much desirable. In this paper, we study the performance analysis of scheduling schemes for multiuser MIMO-OFDM systems employing Orthogonal Space-Frequency Block Coding in g–l fading scenario over frequency selective fading channels. We analyze the advantages of user scheduling in MIMO-OFDM systems employing OSFBC and adaptive modulation…
We treat the problem of movement prediction as a classification task. We assume the existence of a (gradually populated and/or trained) knowledge base and try to compare the movement pattern of a certain object with stored information in order to predict its future location. We introduce a novel distance metric function based on weighted spatial and velocity context used for location prediction…
With the exponential growth in mobile data traffic taking place currently and projected into the future, mobile operators need cost effective ways to manage the load of their networks. Traditionally, this has been achieved by offloading mobile traffic onto Wi-Fi networks due to their low cost and increasingly ubiquitous deployment. Recently, LTE operating in the unlicensed spectrum has drawn s…
Abstract: Energy is a scarce and most vital resource in a wireless sensor network (WSN). Since space-time block coding requires less transmission energy than SISO technique for the same bit error rate (BER), therefore, it is one of the most practical diversity technique for WSN studies. In this work, we have investigated the energy utilization of a simple multiple-input single-output system usi…
Body area networks (BAN) are being developed to serve the mankind, for detection of diseases and tracking of patients. And ultra wideband (UWB) has become the most preferred candidate for the physical layer of BAN. However, UWB BAN will suffer from the interferences from existing wireless networks. Though a number of mitigation techniques have been developed for UWB they will not be feasible f…
The estimation of tag read and no-read zones is the most important preliminary planning step in radio-frequency identification (RFID) system installations. Today, in the ultra-high frequency band (UHF: 860–960 MHz), this estimation is based on either a free-space or a simplified multipath channel model for the signal propagation in the wireless link between the interrogator and the tag. Using…
In this paper, we present an efficient data channel assignment (DCA) scheme for a mixed cell (i.e., a 3G cell with embedded WLANs). Our effort is essential to increase the data request (i.e., a call) handling capacity in 3G systems, with a ‘low request dropping probability’. In UMTS-first DCA scheme prefers 3G channel in dual coverage and reduces vertical handoffs from 3G to WLAN. But it de…
Modeling and analysis of communication link duration in vehicular ad hoc networks (VANETs) is crucial as it directly affects many performance metrics such as packet delivery ratio, throughput and end-to-end delay. In this paper, we investigate the properties of communication link duration in one-dimensional VANETs for different fading channel conditions. We employ a stochastic microscopic mobil…
Abstract: This paper proposes a mobility management protocol for 6LoWPAN wireless sensor networks. In this protocol, the 6LoWPAN architecture is proposed, and both the hierarchical IPv6 address structure and the address configuration algorithm for 6LoWPAN WSN are presented. Based on the proposed architecture, the intra-network and inter-network mobility handover algorithms are proposed. In the…
We address the multicast problem in a wireless multihop network in the presence of errors. Finding the multicast schedule that minimizes the expected number of transmissions, while accounting for both the wireless broadcast advantage (WBA) and the wireless unreliable transmission (WUT) characteristics, has not been solved optimally before. We formally define the problem and propose an initial a…
Due to the growing importance of deploying femtocell technology in the current mobile network operators, data traffic processing and handover (HO) management in such networks are challenging issues. Consequently, due to the mobility of femto users between indoor and outdoor environments, the HO traffic interplay between macrocell and femtocells should be addressed, by determining accurate HO ra…
Abstract: In this paper, we put forward the methods of footprint shift and separation for the virtual topology model of LEO satellite networks, which can reduce the effects of the Polar Regions and cross-seam inter-satellite-links (ISLs) on the virtual topology and improve the utilization of ISLs. Furthermore, a low-load survivable routing protocol called Virtual Snapshot Routing Protocol is p…
In this paper the integration of an RFID system into a wireless sensor node based on an Arduino board is discussed. The main purpose of the proposed solution is to use the memory of a passive RFID transponder to store the data retrieved by the sensors composing the node. This solution can be employed for remote monitoring operations, when no connection is available and then no remote data colle…
The lifetime of wireless sensor network (WSN)is reduced due to the impact caused by channel fading, interference and unbalanced energy consumption. The node’s energy is wasted due to uneven energy consumption for various processes. Communicating the data from source to sink node will consume more power compared to data sensing and processing etc. The channel fading is mitigated through spatia…
In the recent years, the technological improvements on wireless sensor computational capability and versatility have caused a massive use of battery-supplied Wireless Sensor Network (WSN) in many different monitoring applications. The most relevant factors of reliability of such systems are related to the energetic autonomy and the accuracy of the sampled data delivered to the Fusion Center. T…
Gateway discovery is a fundamental process in interconnecting mobile ad hoc network with the Internet. Traditional gateway discovery algorithms adopt the method of periodically broadcast advertisements with a time interval. However, this method does not fulfill the actual requirements from the source nodes and produces some unnecessary overhead. To solve this problem, this paper adopts a novel …
In order to prolong the lifetime of wireless video sensor networks (WVSNs), many methods for visual target tracking are proposed to reduce the energy cost of batterypowered video sensor nodes. Focus on reducing the amounts of image data for computation and communication, this paper presents an energy-efficient method for distributed target tracking inWVSNs. The major Contributions of the propo…
Probability density function (pdf) of the received signal is necessary for the distributed detection fusion when the unreliable channels between the local sensors and the fusion center are considered. Hitherto study has never been made on the statistical distribution of the demodulated OFDM signal over multipath fading channel. Modeling the OFDM system over the multi-path channel, we derived th…
An important issue affecting cellular networks is to make services available to regions of bad or no reception. Femtocells are considered to be the solution to meet the future needs for better indoor coverage, high data rates and capacity in the cellular networks. Since femtocell access points (FAPs) are usually user deployed, thus blind placement of FAPs is inevitable leading to problems of po…
In this paper, we investigate the resource allocation issues in Orthogonal frequency division multiplexing access-based multicast systems that only allows average channel state information of users to be available at the resource manager. In this system, it is impossible to guarantee successful transmission of every data due to instant deep fading. Hence, in order to achieve efficient and reli…
Wireless sensor–actor networks (WSANs) are applicable in versatile domains ranging from very common to those which demand reliable actions in the event area. The unique characteristics of WSANs and the resourceconstrained nature of the constituent sensor nodes give rise to design energy and delay efficient routing protocols. Many researchers have made considerable efforts to meet these challe…
In the paper, a kind of channel noise produced by nodes accessing channel was considered, and this noise was compared with Middleton Class-A noise. It was assumed that the time, space, frequency of channel accessed by nodes were randomized, hence the channel selection can be described as a random matrix. And the random matrix were approximately calculated and analyzed by Krylov subspace method …
In this paper, we present an efficient resource allocation with user discrimination framework for 5G Wireless Systems to allocate multiple carriers resources among users with elastic and inelastic traffic. Each application running on the user equipment (UE) is assigned an application utility function. In the proposed model, different classes of user groups are considered and users are partition…
The goal of fourth generation (4G) mobile communications system is to seamlessly integrate a wide variety of communication services such as high speed data, video and multimedia traffic as well as voice signals. One of the promising approaches in 4G is the Adaptive Orthogonal Frequency Division Multiplexing (AOFDM) technique. In Multiple Input Multiple Output (MIMO)- OFDM, adaptive transmissio…
n Multi-hop Wireless Networks (MWNs), the end-to-end performance degrades exponentially with hop counts and the degree of traffic aggregation at each hop. Fair allocation of bandwidthamong nodes is one of the challenging problems in MWNs. The IEEE 802.11 distributed coordination function standard stipulates long-term equalization of throughput among stations by giving the same number of transm…
In this paper, a comparative study of the simulated symbol error rate (SER) with the theoretical SER of uncoded communication systems is made for selected modulation schemes with and without fading. Slow fading Weibull and Rayleigh channels are considered in this paper. The modulation schemes considered are (1) Binary Phase Shift Keying, (2) Quadrature Phase Shift Keying, (3) Orthogonal Freque…
This letter considers routing in delay tolerant networks whereby nodes have semi-predictable mobility patterns within a time period. We propose a mobility-based routing protocol (MBRP) where nodes construct a space–time graph dynamically. As the space–time graph may be incomplete, MBRP presents a heuristic that evaluates encountered nodes based on their recorded mobility patterns in order t…
This paper presents a modulator and low power ASK demodulator that uses a new technique. This technique uses the dynamic threshold MOSFET to reduce the threshold voltage of diodes connected MOS transistors as a barrier in the design of the envelope detector. This circuit has been simulated in a 90 nm CMOS technology to satisfy EPC Class 1 Generation 2 standard protocol. The proposed circuit can…
The double codebook structures are proposed and applied in LTE-advanced, which can track both longterm and short-term channel state information. In traditional incoherent estimation, precoding matrix indicators (PMI) estimation is performed on each individual subcarrier and some form of averaging procedure then follows to combine the results from individual narrow-band processing. As a result, …
Purpose – The purpose of this paper is to develop a framework for reconceptualising research on school autonomy to redress the limitations of traditional research, strengthen the conceptual links between school autonomy and learning outcomes and offer a range of new strategies for studying the interplay of school autonomy, leadership and learning. Design/methodology/approach – Based on a r…
Purpose – In the context of the creation of a two-year Master of Science in Business Administration programme to offer a scientifically sound and practice-related management education in Switzerland, a curriculum for learning and teaching research methods had to be designed. Major pedagogic challenges were identified and addressed by curricular responses in terms of pluralism in knowledge pro…
Purpose – Although leadership is found to have impact on the followers’ attitudes and performance there is a gap in leadership studies in HEIs, especially having Lithuania in mind. The purpose of this paper is to study the impact of leadership style on job satisfaction of faculty in higher education institutions (HEI). Design/methodology/approach – In order to investigate before mentione…
Purpose – Teacher learning communities (TLCs) formed within subject departments are conceptualized as reform platform for facilitating school improvement and teacher development. The purpose of this paper is to examine the ways in which three TLCs were structured and managed for generating change capability in secondary schools in Hong Kong. Design/methodology/approach – A review of the li…
Abstract: Accelerated formation and tissue accumulation of advanced glycation end products (AGEs), reflecting cumulative glycemic and oxidative stress, occurs in agerelated and chronic diseases like diabetes mellitus (DM) and renal failure, and contributes to vascular damage. Skin auto fluorescence (AFR), a noninvasive measurement method, reflects tissue accumulation of AGEs. AFR has been repo…
Abstract: Baillonella toxisperma , Pentaclethra macrophylla and Trichoscypha abut areimportant foods for communities living around forests in Cameroon. Information on the nutritional value and bioactive content of these foods is required to establish their contribution to the nutrition and health of the communities.Samples of the three foods were obtained from four villages in east and three v…
Abstract: Secondary hyperparathyroidism is common in patients with mineral and bone disorders related to chronic kidney disease. Guidelines for the management of secondary hyperparathyroidism in hemodialysis patients have been promulgated, but evidence on the relationship between treatment and survival is still insufficient. Studying hemodialysis patients with secondary hyperparathyroidism, we …
Abstract: Aim: Most family caregivers continue their caregiving for frail relatives after admitting them to long-term care facilities. The characteristics of this caregiving differ from those related to caregiving in home-care settings. Thus, a new tool to evaluate the burden of family caregivers in institutional settings is needed. The aim of this study was to develop a new scale, the Caregiv…
Impaired social cognition is considered a core contributor to unfavorable psychosocial functioning in schizophrenia. Rather than being a unitary process, social cognition is a collection of multifaceted processes that recruit multiple brain structures, thus structural and functional neuroimaging techniques are ideal methodologies for revealing the underlying pathophysiology of impaired social c…
Abstract Aim: This mixed methods study describes the post-transplantation daily life of pre-adolescents and adolescents who had undergone living donor liver transplantation and their parents. Methods: Nine parent–child dyads were enrolled and all children were living donor liver transplant recipients. Three participants were pre-adolescents and the six were adolescents. Five of the parents …
Abstract: Aim: This study aimed to identify the effect of fall prevention measures and characteristics of wards on the rate of pediatric falls. Methods: Data on study variables were collected using a cross-sectional design and questionnaires of 603 randomized general hospitals in Japan. Among the hospitals that were contacted, 252 (41.8%) returned their questionnaires. The questionnaires incl…
the neutrophilic dermatoses mainly caused by activated neutrophils and monocytes. Granulocyte and monocyte adsorption apheresis (GCAP) is a useful extracorporeal circulation therapy for removal of activated granulocytes and monocytes. In this study,GCAP was used to treat three patients with different types of GPP; the diagnoses indicated patient 1 had GPP, patient 2 had GPP developed from psori…
Abstract: Several abnormalities of the cardiovascular system are observed in most cases of chronic kidney disease (CKD). Mechanisms underlying these abnormalities are complicated, and several factors contribute to their pathogenesis. Of these factors, oxidative stress and uremic toxins are considered to play key roles in the progression of cardiovascular disease (CVD) in CKD. Oxidative stress i…
Purpose – The purpose of this paper is to explore/investigate various issues of teachers’ motivation in public sector Higher Educational Institutions of Pakistan. Design/methodology/approach – This is an exploratory research where surveys have been conducted in the well known public sector Universities of Pakistan; primary data have been collected through questionnaire and in depth face …
Purpose – The purpose of this paper is to explore not only the academic measures such as grade point average of success of college-to-university transfer programs (Pathway Programs), but also the social-cultural facilitators and barriers throughout the students’ Pathway experience. Design/methodology/approach – The experience of students and academic advisors moving between Queensdale Co…
Purpose – The purpose of this paper is to present the results of an exploratory study that investigates Portuguese academics’ conceptions concerning the temporal properties of e-learning, in the context of traditional Higher Education Institutions. Design/methodology/approach – Grounded Theory methodology was used to systematically analyse data collected in semi-structured interviews wit…