FDTD modelling, measurements and analyses of post reception synthetic focusing techniques in ground penetrating radars.

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN040771 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Emergency TeleOrthoPaedics m-health system for wireless communication links

For the first time, a complete wireless and mobile emergency TeleOrthoPaedics system with field trials and expert opinion is presented. The system enables doctors in a remote area to obtain a second opinion from doctors in the hospital using secured wireless telecommunication networks. Doctors can exchange securely medical images and video as well as other important data, and thus perform remote consultations, fast and accurately using a user friendly interface, via a reliable and secure telemedicine system of low cost. The quality of the transmitted compressed (JPEG2000) images was measured using different metrics and doctors opinions. The results have shown that all metrics were within acceptable limits. The performance of the system was evaluated successfully under different wireless communication links based on real data

Measurement campaign on transmit delay diversity for mobile DVB-T/H systems

This article is posted here with permission from IEEE - Copyright @ 2010 IEEEThis paper describes the work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Delay Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial was performed during the winter of 2007/2008 in Uxbridge (UK) to validate predictions from theoretical modeling and laboratory simulations. The transmissions were performed in the 730 MHz frequency band with a DVB-T/H transmitter and a mean power of 18.4 dBW. The impact of the transmit antenna separation and the MPE-FEC was also investigated. It is shown that transmit delay diversity significantly improves the quality of reception in fast fading mobile broadcasting application

Static Pipeline Network Performance Optimisation Using Dual Interleave Routing Algorithm

In the recent years, there is an increasing demand on multi-hop wireless sensor networks (WSN) especially for remote condition and integrity monitoring of oil and gas pipelines. The sensing points are connected through WSN points, known as a wireless communication medium, between the remotely measured locations on a pipeline and a centralised monitoring station, located some distance away. Generally, WSN deployment on a multi-hop linear topology has critical factors that contribute towards overall degrading of network performance proportional to the number of nodes. This is especially true in highly dense networks. In general, such a drawback contributes towards poor network reliability, low network capacity, high latency, and inequality with snowballing effect, increasing in the direction of the destination node. This paper introduces the Dual Interleaving Linear Static Routing (DI-LSR) for a multi-hop linear network with high reliability and efficiency to significantly enhance the overall network performance of a pipeline network. The DI-LSR was tested and analysed according to IEEE 802.11 standard in a various simulation environment for future real-time deployment in a pipeline network

TCP Performance And Throughput Fairness Optimization In A Multi-Hop Pipeline Network

Node starvation wireless sensor network (WSN) is a critical factor that affects the overall performance in a typical multi-hop linear network especially in an extensive scale network. The unfairness of sharing network resources with all source nodes in a multi-hop linear network amplifies the node starvation that often results in passive nodes in a network. This factor becomes critical with the increasing network density, aggressive data transfer, single destination node and inadequate data scheduling. This paper highlights the Delayed acknowledgement timeout for flat one-tier throughput critical application model (DAT-FTCAM) a mathematical fairness model that ensure maximum throughput fairness for pipeline network scenario. The DAT-FTCAM enables the users to calculate the maximum delayed acknowledgement timeout for transmission control protocol (TCP) proportional to the travel time or difference between a source and a destination node. The implementation of DAT-FTCAM technique with modified TCP parameters on NS2 has revealed a network fairness index of above 0.99 with optimum network performance in a scalable pipeline network. The DAT-FTCAM decreases data packet collision and eliminates passive nodes in a pipeline network with optimum throughput fairnes

Self-organising comprehensive handover strategy for multi-tier LTE-advanced heterogeneous networks

Long term evolution (LTE)-advanced was introduced as real fourth generation (4G) with its new features and additional functions, satisfying the growing demands of quality and network coverage for the network operators' subscribers. The term muti-tier has also been recently used with respect to the heterogeneity of the network by applying the various subnetwork cooperative systems and functionalities with self-organising capabilities. Using indoor short-range low-power cellular base stations, for example, femtocells, in cooperation with existing long-range macrocells are considered as the key technical challenge of this multi-tier configuration. Furthermore, shortage of network spectrum is a major concern for network operators which forces them to spend additional attentions to overcome the degradation in performance and quality of services in 4G HetNets. This study investigates handover between the different layers of a heterogeneous LTE-advanced system, as a critical attribute to plan the best way of interactive coordination within the network for the proposed HetNet. The proposed comprehensive handover algorithm takes multiple factors in both handover sensing and decision stages, based on signal power reception, resource availability and handover optimisation, as well as prioritisation among macro and femto stations, to obtain maximum signal quality while avoiding unnecessary handovers

Mutual Coupling Reduction with a novel Fractal Electromagnetic Band Gap Structure

This work shows the effect of a novel Fractal based Electromagnetic Band Gap (FEBG) structure between dual PIFAs antenna elements. The FEBG structure without any shorting pins builds on a well-known fractal structure called Sierpinski carpet, where two iterations have been applied as a uniplanar EBG between dual PIFAs elements to increase the isolation. The proposed antenna can operate at approximately 2.65 GHz for wireless Long Term Evolution (LTE) application with compact design dimensions. The simulations are carried out with Ansoft HFSS ver 17.0. The second iterative order FEBG band-gap characteristic is verified using more computationally efficient analysis. An investigation on coupling reduction showed more than 27 dB, and 40 dB in E-plane and H-plane; respectively between the dual antenna elements is achieved for an antenna spacing less than half wavelength. The proposed antennas with and without second iterative order FEBG are fabricated and measured. The measurement results are in good agreement with the simulated results. Moreover, the envelope correlation of antenna elements with the proposed FEBG is quite smaller than that of antenna elements without FEBG, which gives the proposed system an excellent diverse performance and suitable for the use in low-frequency narrow-band MIMO applications