Enhanced Inter-Cell Interference Coordination Challenges in Heterogeneous Networks

3GPP LTE-Advanced has started a new study item to investigate Heterogeneous Network (HetNet) deployments as a cost effective way to deal with the unrelenting traffic demand. HetNets consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access network and the end-users, has the potential to provide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Nevertheless, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. In this article, we present the concept of heterogeneous networks and also describe the major technical challenges associated with such network architecture. We focus in particular on the standardization activities within the 3GPP related to enhanced inter-cell interference coordination.Comment: 12 pages, 4 figures, 2 table

Accuracy Enhancement of a Multi-Resolution Indoor Propagation Simulation Tool by Radiation Pattern Synthesis

International audienceThis paper presents an innovative approach that offers both a precise modeling of the propagation environment and a reduced computational load taking advantage of a multi-resolution algorithm. In this approach, radiating sources are simulated as point sources and are thus obviously omnidirectional leading to an important limit of the method. This paper tackles this problem by introducing multi-point sources. A regularized radiation pattern synthesis is then proposed for modeling particular radiation patterns. This approach enhances the accuracy of the predictions while preserving fast calculation time

Computationally Efficient MR-FDPF and MR-FDTLM Methods for Multifrequency Simulations

International audienceWe propose a modification of the multi-resolution frequency domain ParFlow (MR-FDPF) method that allows simulating radio propagation channels in a frequency range. The performance of the proposed MR-FDPF implementation has been analyzed based on different realistic propagation scenarios. We also analyze the possibility of applying the multi-resolution frequency domain approach to the well-known transmission-line matrix method. The proposed multi-resolution frequency domain transmission-line matrix method provides a computationally efficient way of modeling radio wave propagation in threedimensional space at multiple frequencies

Computationally Efficient MR-FDPF Method for Multifrequency Simulations

In this report, we propose a modification of the multi-resolution frequency domain ParFlow (MR-FDPF) method that allows simulating radio propagation channels in a frequency range. The performance of the proposed MR-FDPF implementation has been analyzed based on different realistic propagation scenarios

The Adaptive Multi-Resolution Frequency-Domain ParFlow (MR-FDPF) Method for Indoor Radio Wave Propagation Simulation. Part I : Theory and Algorithms

This report presents the theoretical background and new developments of the multi-resolution frequency domain ParFlow (MR-FDPF) approach for the calculus or radio propagation in Indoor environments for centimetric waves. This method has been developed to face the need of a best understanding of Indoor propagation and to help the WiFi network planning task. Indeed, the development of a wireless design tool is based firstly on a radio propagation engine to predict accurately the radio coverage of access points, with a limited computational load. Usual approaches in the literature are based on either empiric modeling, deducted from measurements, or geometrical optic formalism leading to ray-tracing. While the former suffers a lake of accuracy, the later needs a trade-off between accuracy and computational load, often difficult to assess. The approach proposed herein is based on a finite element approach. Once the problem developed in the frequency domain, the linear system thus obtained is solved in two steps: a pre-processing step which consists in an adaptive multi-resolution (multi-grid) pre-conditioning and a propagation step. The second step computes the coverage of a point source with an up-and-down propagation through the binary tree associated with the multi-resolution description. This approach solves exactly the linear system but with a strongly reduced computational complexity when compared to the time domain approach. For example, a full AP coverage at a macroscopic resolution and for an environment of 1000x600 pixels (i.e. $6000m2$ at a $10cm$ resolution) lasts less than $200ms$

On Predicting Large Scale Fading Characteristics with the MR-FDPF Method

International audienceThe MR-FDPF (Multi-Resolution Frequency Domain Partial Flow) method is proven to be a fast and efficient method to simulate radio wave propagation. It is a deterministic model which can provide an accurate radio coverage prediction. In reality, radio channels have the nature of randomness due to e.g. moving people or air flow. Thus they can not be rigorously simulated by a pure deterministic model. However, it is believed that some statistics can be extracted from deterministic models and these statistics can be very useful to describe radio channels in reality. In this paper, large scale fading statistical characteristics are extracted based on the MR-FDPF method. They are validated by comparison to both the theoretical result and measurement. The match also demonstrates that MR-FDPF is capable of simulating large scale fading

Three new PAX6 mutations including one causing an unusual ophthalmic phenotype associated with neurodevelopmental abnormalities

The PAX6 gene was first described as a candidate for human aniridia. However, PAX6 expression is not restricted to the eye and it appears to be crucial for brain development. We studied PAX6 mutations in a large spectrum of patients who presented with aniridia phenotypes, Peters' anomaly, and anterior segment malformations associated or not with neurological anomalies.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Planck pre-launch status : The Planck mission

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