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2189 research outputs found
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Prospects and QoS Requirements in 5G Networks, Journal of Telecommunications and Information Technology, 2015, nr 1
Get PDFIn this article the requirements to some number of KPI that determine the quality of service (QoS) in 5G networks are formulated. The proposed QoS requirements are based on the analysis of functional requirements to 5G networks and traffic parameters for HD video and massive M2M services, which will be highly demanded in 2020. One of the 5G development paradigms is the network function virtualization (NFV) including cloud radio access and cloud core networks. The authors have proposed the concept of function blocks CQMF and CQCF to control and monitor QoS, which are implemented as part of the 5G network cloud infrastructure
Quality Expectations of Mobile Subscribers, Journal of Telecommunications and Information Technology, 2015, nr 1
Get PDFMobile systems, by nature, have finite resources. Radio spectrum is limited, expensive and shared between many users and services. Mobile broadband networks must support multiple applications of voice, video and data on a single IP-based infrastructure. These converged services each have unique traffic holding and quality requirements. A positive user experience must be obtained through efficient partitioning of the available wireless network resources. The 3rd Generation Partnership Project (3GPP) has developed a comprehensive Quality of Service (QoS) parameter to address this problem. The regular control of service quality is critical for operators to ensure user Quality of Experience (QoE), establish new business models and monetize services. It enables operators to employ fair-use resource policies and maintain network performance during peak traffic times. Wireless mobile communication is tending towards an integrated system of Internet and telecommunication technologies, where mobile users move freely anytime and everywhere. They desire to communicate with any device using the best service available. In this paper QoS management issues in mobile communication are described. The authors present an insight into subscriber behavior and related factors that affect the QoE of mobile data services
Revising and Improving the ITU-T Recommendation P.912, Journal of Telecommunications and Information Technology, 2015, nr 1
Get PDFIt was once thought that high Quality of Service (QoS) performance solves recurrent problems of lowquality multimedia services. Since then, solutions have been proposed to ensure a high level of Quality of Experience (QoE). In this paper, the author attempts to outline an understanding of an accurate meaning of multimedia services quality. Starting from QoS and passing through generalized QoE, the author focuses on subjective aspects and objective quality modeling and optimization of visual performance for Target Recognition Video (TRV) applications (such as video surveillance), to outline the ITU-T standardization path in this area. The revising the ITU-T Recommendation P.912 is proposed to reflect improved subjective test techniques developed since this Recommendation was approved. Also at least some existing errors of reasoning are predicted, which are likely to become evident for the industry in the next decade. Finally, the author invites all researchers working on topics related to TRV to join him in the process of improving P.912
Improvement of LTE Downlink Channel Estimation Performance by Using an Adaptive Pilot Pattern, Journal of Telecommunications and Information Technology, 2015, nr 2
Get PDFThis paper proposes an adaptive pilot pattern to improve channel estimation performance for LTE downlink system with high mobility. The downlink pilot positions are predefined in the time and frequency domain with fixed pilot pattern in LTE standard. However, that pilot structure is not efficient in a fast time varying channel, and leads to a decrease of channel estimation performance. The authors propose and evaluate the performance of LTE downlink channel estimation using an adaptive pilot scheme to optimally use pilot tones over time varying channels. It is shown that only seven bits of additional wide-band feedback per frame and per user are required to optimally support adaptive pilot pattern. Simulation results show that the proposed method allows high performance in terms of throughput and channel estimation error. This analysis shows that LTE downlink throughput could be increased over 4%
Multi-layered Bayesian Neural Networks for Simulation and Prediction Stress-Strain Time Series, Journal of Telecommunications and Information Technology, 2015, nr 3
Get PDFThe aim of the paper is to investigate the differences as far as the numerical accuracy is concerned between feedforward layered Artificial Neural Networks (ANN) learned by means of Kalman filtering (KF) and ANN learned by means of the evidence procedure for Bayesian technique. The stress- strain experimental time series for concrete hysteresis loops obtained by the experiment of cyclic loading is presented as considered example
Detecting Security Violations Based on Multilayered Event Log Processing, Journal of Telecommunications and Information Technology, 2015, nr 4
Get PDFdesign. First layer, named the event source layer, describes sources of information that can be used for misuse investigation. Transport layer represents the method of collecting event data, preserving it in the form of logs and passing it to another layer, called the analysis layer. This third layer is responsible for analyzing the logs' content, picking relevant information and generating security alerts. Last layer, called normalization layer, is custom software which normalizes and correlates produced alerts to raise notice on more complex attacks. Logs from remote hosts are collected by using rsyslog software and OSSEC HIDS with custom decoders and rules is used on a central log server for log analysis. A novel method of handling OSSEC HIDS alerts by their normalization and correlation is proposed. The output can be optionally suppressed to protect the system against alarm flood and reduce the count of messages transmitted in the network
Polish Personal Identity Card as a Tool for Identity Theft, Journal of Telecommunications and Information Technology, 2015, nr 2
Get PDFThis article discusses the changes that are the result of entry the new personal ID card issued in Poland. The new document contains less information about the owner, i.e. height, eye color or signature, so that the risk of identity theft is significantly greater
On Providing Cloud-awareness to Client's DASH Application by Using DASH over HTTP/2, Journal of Telecommunications and Information Technology, 2015, nr 4
Get PDFMobile Cloud Networks group together mobile users and clouds containing content servers. Hence, they are an ideal framework for media content delivery. Streams witching adaptive video players cope well with some limitations of Mobile Cloud Networks as low bandwidth and bandwidth variability in access network. Nonetheless, other limitations, as cloud congestion, are difficult to be managed by the video players. This paper presents a system for discovering fault situations at the cloud (e.g., cloud congestion) and notifying to the video player, which will take appropriate actions for saving the quality of media transmission. In proposed implementation the video application is DASH-capable and adaptation action may be both stream rate adaptation and content server adaptation. The communication between client and server uses \bidirectional" communication feature of HTTP/2 thanks to the new deployed modules running DASH over HTTP/2 in both client's and server's applications