Search results for " networking"
showing 10 items of 1264 documents
Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence
2015
In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…
RF-Based Human Activity Recognition: A Non-stationary Channel Model Incorporating the Impact of Phase Distortions
2019
This paper proposes a non-stationary channel model that captures the impact of the time-variant (TV) phase distortion caused by hardware imperfections. The model allows for studying the spectrogram of in-home radio channels influenced by walking activities of the home user under realistic non-stationary propagation conditions. The resolution of the spectrogram is investigated for the von-Mises distribution of the phase distortion. It is shown that high-entropy distributions considerably mask fingerprints of the user activity on the spectrogram of the channel. For an orthogonal frequency-division multiplexing (OFDM) system, a computationally simple method for mitigating the undesired phase r…
Embedded Processing and Compression of 3D Sensor Data for Large Scale Industrial Environments
2019
This paper presents a scalable embedded solution for processing and transferring 3D point cloud data. Sensors based on the time-of-flight principle generate data which are processed on a local embedded computer and compressed using an octree-based scheme. The compressed data is transferred to a central node where the individual point clouds from several nodes are decompressed and filtered based on a novel method for generating intensity values for sensors which do not natively produce such a value. The paper presents experimental results from a relatively large industrial robot cell with an approximate size of 10 m ×
Development of a big data bank for PV monitoring data, analysis and simulation in COST Action 'PEARL PV'
2019
COST Action entitled PEARL PV aims at analyzing data of monitored PV systems installed all over Europe to quantitatively evaluate the long-term performance and reliability of these PV systems. For this purpose, a data bank is being implemented that can contain vast amounts of data, which will enable systematic performance analyses in combination with simulations. This paper presents the development process of this data bank.
Towards Diagrammatic Patterns
2008
This article presents the idea that the graphical representation (concrete syntax) of a visual language can be specified based on some pre-defined diagrammatic patterns. A diagram from the Specification and Description Language (SDL) is used as illustration.
LCL - A Graphical Meta-Language for Specification of Language Constraints
2015
The Object Constraint Language (OCL) is commonly used for constraints in meta-model-based language specifications. However, it may be advantageous to have a domain-specific constraint meta-language optimised for language specifications. A survey of OCL usage in language specifications has been performed, in order to gain an understanding of common constraint patterns. This is used as a starting point for defining a new meta-language for language constraints, Language Constraint Language (LCL), that has an intuitive graphical syntax.
Adapting hierarchical bidirectional inter prediction on a GPU-based platform for 2D and 3D H.264 video coding
2013
The H.264/AVC video coding standard introduces some improved tools in order to increase compression efficiency. Moreover, the multi-view extension of H.264/AVC, called H.264/MVC, adopts many of them. Among the new features, variable block-size motion estimation is one which contributes to high coding efficiency. Furthermore, it defines a different prediction structure that includes hierarchical bidirectional pictures, outperforming traditional Group of Pictures patterns in both scenarios: single-view and multi-view. However, these video coding techniques have high computational complexity. Several techniques have been proposed in the literature over the last few years which are aimed at acc…
Power allocation for two-cell two-user joint transmission
2012
In this paper, we develop a power allocation scheme for the downlink of a two-cell two-user joint transmission system. The objective is to maximize the sum rate under per-cell power constraints. We study a worst case scenario where the carrier phases between the two base stations are un-synchronized, so that joint transmission must be performed without precoding. The derived power allocation scheme is remarkably simple, i.e., each cell transmits with full power to only one user. Note that joint transmission is still possible, when two cells select the same user for data transmission. Moreover, we prove that, in this scenario, the joint transmission case happens with higher probability when …
Computational Offloading in Mobile Edge with Comprehensive and Energy Efficient Cost Function: A Deep Learning Approach
2021
In mobile edge computing (MEC), partial computational offloading can be intelligently investigated to reduce the energy consumption and service delay of user equipment (UE) by dividing a single task into different components. Some of the components execute locally on the UE while the remaining are offloaded to a mobile edge server (MES). In this paper, we investigate the partial offloading technique in MEC using a supervised deep learning approach. The proposed technique, comprehensive and energy efficient deep learning-based offloading technique (CEDOT), intelligently selects the partial offloading policy and also the size of each component of a task to reduce the service delay and energy …
Reducing Power Consumption of Wireless Networks Through Collaborative DMC Mobile Clusters
2017
Reducing the energy consumption of the wireless network is significantly important to the economic and ecological sustainability of the ICT industry, as high energy consumption may limit the performance of wireless networks and is one of the main network costs. To solve energy consumption problem, especially on the terminal side, a scheme known as distributed mobile cloud (DMC) is considered to be a potential solution. Multiple mobile terminals (MTs) can cooperative to take advantage of good quality links among the MTs to save energy when receiving from the Base Station (BS). In this paper, we aim to find the optimal transmit power to further reduce the energy consumption of DMC. From simul…