Performance analysis with wireless power transfer constraint policies in full-duplex relaying networks

In practice, full-duplex (FD) transmission mode not only helps extend the coverage but also lengthen network lifetime. In this paper, we develop wireless power supply policies, namely separated power (SP) and harvested power (HP) to propose a flexible architecture at the relay node in FD decode-and-forward (DF) relaying networks considering time switching-based relaying protocol (TSR) to achieve optimal time used for a communication process. This transmission mode requires more processing procedure at the relay, i.e. antenna installations and radio frequency (RF) self-interference cancellation. We evaluate the optimal power constraints in case of SP and HP to achieve better power consumption efficiency at the relay node. More importantly, closed-form expressions for outage probability and throughput are provided, and we also use numerical and simulation results to compare SP with HP.Web of Science234767

Present state of investment casting technology

Tato bakalářská práce popisuje proces lití na vytavitelný model v jednotlivých fázích výroby. Tedy od výroby matečné formy, voskového modelu, keramické skořepiny, vytavování vosku, odlévání, až po dokončující operace a konečnou kontrolu odlitku. Práce je zaměřena na nejnovější trendy v těchto oblastech.This bachelor’s thesis describes investment casting process in each phases of manufacturing the final casting i.e. from master die, wax pattern, ceramic shell, dewaxing process, metal pouring up to finishing operations and final casting inspection. This work is focused on the latest trends in these areas.

Modern network security trends of 802.11 standard

Táto bakalárska práca sa zaoberá zabezpečením standardu 802.11. V úvode práce je detailne popísaný tento štandard a jeho jednotlivé zložky. V ďalšej časti sú popísané možnosti jeho zabezpečenia a prípadné nedostatky v nich. V práci sú uvedené praktické ukážky vybraných útokov. A na konci zhodnotenie momentálneho stavu a možnosti ako sa vyhnúť slabinám v týchto zabezpečeniach.Táto bakalárska práca sa zaoberá zabezpečením standardu 802.11. V úvode práce je detailne popísaný tento štandard a jeho jednotlivé zložky. V ďalšej časti sú popísané možnosti jeho zabezpečenia a prípadné nedostatky v nich. V práci sú uvedené praktické ukážky vybraných útokov. A na konci zhodnotenie momentálneho stavu a možnosti ako sa vyhnúť slabinám v týchto zabezpečeniach.

Real time traffic simulator for self-adaptive navigation system validation

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Impact of H.264/AVC and H.265/HEVC compression standards on the video quality for 4K resolution

This article deals with the impact of H.264/AVC and H.265/HEVC compression standards on the video quality for 4K resolution. In the first part a short characteristic of both compression standards is written. The second part focuses on the well-known objective metrics which were used for evaluating the video quality. In the third part the measurements and the experimental results are described

Network degradation effects on different codec types and characteristics of video streaming

Nowadays, there is a quickly growing demand for the transmission of voice, video and data over an IP based network. Multimedia, whether we are talking about broadcast, audio and video transmission and others, from a global perspective is growing exponentially with time. With incoming requests from users, new technologies for data transfer are continually developing. Data must be delivered reliably and with the fewest losses at such high speed. Video quality as part of multimedia technology has a very important role nowadays. It is influenced by several factors, where each of them can have many forms and processing. Network performance is the major degradation effect that influences the quality of resulting image. Poor network performance (lack of link capacity, high network load…) causes data packet losses or different delivery time for each packet. This work focuses exactly on these network phenomena. It examines the impact of different delays and packet losses on the quality parameters of triple play services, to evaluate the results using objective methods. The aim of this work is to bring a detailed view on the performance of video streaming over IP-based networks

Adaptive reservation of network resources according to video classification scenes

Video quality evaluation needs a combined approach that includes subjective and objective metrics, testing, and monitoring of the network. This paper deals with the novel approach of mapping quality of service (QoS) to quality of experience (QoE) using QoE metrics to determine user satisfaction limits, and applying QoS tools to provide the minimum QoE expected by users. Our aim was to connect objective estimations of video quality with the subjective estimations. A comprehensive tool for the estimation of the subjective evaluation is proposed. This new idea is based on the evaluation and marking of video sequences using the sentinel flag derived from spatial information (SI) and temporal information (TI) in individual video frames. The authors of this paper created a video database for quality evaluation, and derived SI and TI from each video sequence for classifying the scenes. Video scenes from the database were evaluated by objective and subjective assessment. Based on the results, a new model for prediction of subjective quality is defined and presented in this paper. This quality is predicted using an artificial neural network based on the objective evaluation and the type of video sequences defined by qualitative parameters such as resolution, compression standard, and bitstream. Furthermore, the authors created an optimum mapping function to define the threshold for the variable bitrate setting based on the flag in the video, determining the type of scene in the proposed model. This function allows one to allocate a bitrate dynamically for a particular segment of the scene and maintains the desired quality. Our proposed model can help video service providers with the increasing the comfort of the end users. The variable bitstream ensures consistent video quality and customer satisfaction, while network resources are used effectively. The proposed model can also predict the appropriate bitrate based on the required quality of video sequences, defined using either objective or subjective assessment.Web of Science216art. no. 194

Prediction model of triple play services for QoS assessment in IP based networks

This paper brings a QoS (Quality of Service) assessment model which can estimate voice and video quality. Based on the proposed model, speech or video quality is computed with regard to congestion management QoS configuration in the network and its level of total utilization. The contribution of this paper lies in designing a new mathematical model capable of predicting the quality of multimedia services respecting network behavior and performance. Index Terms—delay, E-Model, packet loss, QoS, SSIM, triple play.Web of Science10423923

Two-way half duplex decode and forward relaying network with hardware impairment over Rician fading channel: system performance analysis

In this paper, the system performance analysis of a two-way decode and forward (DF) relaying network over the Rician fading environment under hardware impairment effect is proposed, analyzed and demonstrated. In this analysis, the analytical mathematical expressions of the achievable throughput, the outage probability, and ergodic capacity were proposed, analyzed and demonstrated. After that, the effect of various system parameters on the system performance is deeply studied with closed-form expressions for the system performance. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions. The numerical results demonstrated and convinced the effect of the system parameters on the system performance of the two-way DF relaying network. The results show that the analytical mathematical and simulated results match for all possible parameter values.Web of Science242787

Outage performance analysis of non-orthogonal multiple access with time-switching energy harvesting

In recent years, although non-orthogonal multiple access (NOMA) has shown its potentials thanks to its ability to enhance the performance of future wireless communication networks, a number of issues emerge related to the improvement of NOMA systems. In this work, we consider a half-duplex (HD) relaying cooperative NOMA network using decode-and-forward (DF) transmission mode with energy harvesting (Ell) capacity, where we assume the NOMA destination (D) is able to receive two data symbols in two continuous time slots which leads to the higher transmission rate than traditional relaying networks. To analyse EH, we deploy time-switching (TS) architecture to comprehensively study the optimal transmission time and outage performance at D. In particular, we are going to obtain closed-form expressions for outage probability (OP) with optimal TS ratio for both data symbols with both exact and approximate forms. The given simulation results show that the placement of the relay (R) plays an important role in the system performance.Web of Science253918