Search results for "Transmission"
showing 10 items of 2080 documents
Voice traffic bicasting enhancements in mobile HSPA network
2014
This paper discusses methods for improving the effectiveness of delivering voice traffic over High-Speed Downlink Packet Access (HSDPA) network by employing transmission diversity with Single-Frequency Dual-Cell (SF-DC) Aggregation that is part of the Multiflow specification. SF-DC Aggregation allows the user to be served at the same time by two different cells. The enhancements discussed in the paper capitalize strongly on the availability of the composed Channel Quality Indication (CQI) feedback at both serving cells. According to the results obtained from the network simulations, the ability to select the better channel for each voice transmission significantly decreases the required tra…
Introduction of Multiflow for HSDPA
2012
This paper introduces a multi-cell transmission scheme for High-Speed Downlink Packet Access (HSDPA) networks, called Multiflow. In this concept, downlink data is transmitted to a user terminal at the border of two cells from one or both of the cells. The cells may belong to same NodeB or to two different NodeBs. The data flows are separated by different scrambling codes used by each associated cell, thus the flows can be treated independently. This provides increased multi-user diversity by means of flexibility in downlink resource management, in addition to the spatial diversity of multiple transmission locations. Another important gain mechanism for this scheme is realized by short-term …
On optimal relay placement for improved performance in non-coverage limited scenarios
2014
Low power nodes have been a hot topic in research, standardization, and industry communities, which is typically considered under an umbrella term called heterogeneous networking. In this paper we look at the problem of deploying optimally low power nodes in the context of relay networking, when an operator connects low power nodes (or small cells) via the wireless backhaul that uses the same spectrum and the same wireless access technology. We present an analytical model that can calculate optimal coordinates for low power nodes based on the input parameters, such as preferred number of nodes, their transmission power, parameters of the environment etc. The analytical calculations are comp…
Lattice Boltzmann Simulations at Petascale on Multi-GPU Systems with Asynchronous Data Transfer and Strictly Enforced Memory Read Alignment
2015
The lattice Boltzmann method is a well-established numerical approach for complex fluid flow simulations. Recently general-purpose graphics processing units have become accessible as high-performance computing resources at large-scale. We report on implementing a lattice Boltzmann solver for multi-GPU systems that achieves 0.69 PFLOPS performance on 16384 GPUs. In addition to optimizing the data layout on the GPUs and eliminating the halo sites, we make use of the possibility to overlap data transfer between the host CPU and the device GPU with computing on the GPU. We simulate flow in porous media and measure both strong and weak scaling performance with the emphasis being on a large scale…
One-pot synthesis and characterization of subnanometre-size benzotriazolate protected copper clusters
2012
A simple one-pot method for the preparation of subnanometre-size benzotriazolate (BTA) protected copper clusters, Cu(n)BTA(m), is reported. The clusters were analyzed by optical and infrared spectroscopy, mass spectrometry and transmission electron microscopy together with computational methods. We suggest a structural motif where the copper core of the Cu(n)BTA(m) clusters is protected by BTA-Cu(i)-BTA units.
Transmission delay in technology-mediated interaction at work
2015
This paper investigates transmission delay in technology-mediated interaction from a participant’s perspective. The approach chosen here contrasts with previous studies of delay: only what is seen, heard and done at one end (i.e., what is available on screen) is considered in the analysis. It is argued that participants themselves lack access to the other sides of their interactions as they unfold at remote locations, and they thus cannot observe and deal with delay from an outside perspective. Analyzing single cases of delay-ininteraction within the framework of conversation analysis, the focus is on dispersed conversation partners’ resources to detect a problem, and to make visible and re…
Effect of thermal annealing on the luminescence of defective ZnO nanoparticles synthesized by pulsed laser ablation in water
2016
This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH,…
Engine/Transmission Matching
2014
This chapter deals with the forecasting of vehicle performance on the road, according to the installed engine. It begins with Section 1, which shows the calculation of the resistance to motion, that is, the forces that the vehicle must overcome to advance on flat roads and uphill. The calculation excludes accidental resistance in curves because it is not essential for predicting the behavior of the vehicle on the road. Section 2 begins with the power characteristic, the forecast by traction–speed and power–speed diagrams, calculation of gear ratios, and then passing to the limits to the estimated acceleration, feature consumption, and distance. This chapter concludes with a section on the d…
Counting the minimum node weight spanning trees for broadcast transmission in wireless sensor networks
2017
Artykuł przedstawia algorytm optymalizacji zużycia energii dla broadcastu w sieciach sensorowych. Transmisja broadcastu pozwala na wysłanie danych do wszystkich portów składających się na sieć. Bezprzewodowe sieci sensorowe zbudowane są z rozproszonych urządzeń pomiarowych. Mają one ograniczone zasoby energii. W tym artykule stworzymy model sieci sensorowej z jednym sensorem broadcastującym. Do tej sieci użyjemy algorytmu znajdującego minimalne spinające drzewo wag, pozwalające na oszczędne wykorzystanie energii sensorów.
Asymmetric effects of monetary policy shocks across US states
2019
This paper provides new empirical evidence of the asymmetric effects of monetary policy shocks across regions. Using a measure of unanticipated changes in the Fed's policy rates over the period 1969Q3–2008Q4 and a local projection method extended to account for spatial effects, we find that monetary policy tightening leads to a long-lasting decrease in states' real personal income, with asymmetric effects across states that are amplified by spatial spillovers. The paper then investigates the role played by several transmission channels finding larger contractionary effects of monetary policy tightening in states with higher manufacturing share, smaller firms, smaller banks and higher house …