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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analýza českého telekomunikačního trhu / Analysis of the Czech telecommunications market

Hofman, Adam January 2016 (has links)
This diploma thesis focuses on the telecommunications field and specifically on the analysis of the Czech telecommunications market. Theoretical part of the thesis is focused on the historical development of telecommunications in terms of technological trends in the world and their subsequent transfer to Czech market. The practical part deals with the analysis of the Czech market, according to selected criteria, particularly in terms of privided services, their quality and technological solutions. The emphasis is on the analysis of operation of the mobile telecommunication and data services providers in the Czech Republic. The result of this diploma thesis is the analysis of the current state of the Czech telecommunications market in common with positive forecasts.
2

A LTE UPCUL architecture design combining Multi-Blackboards and Pipes & Filters architectures

Jiang Axelsson, Bohui January 2015 (has links)
Context. The single blackboard architecture is widely used in the LTE application area. Despite its several benefits, this architecture limits synchronization possibilities of the developed systems and increases the signal operational latency. As a result the DSP (Digital Signal Processing) utilization is suboptimal. Objectives. In this thesis, we design a new architecture, which combines concepts of Multi-Blackboards and Pipes & Filters architectures, as a replacement for the current single blackboard architecture at Ericsson. The implementation of the new architecture makes the environment asynchronous. We evaluate the new architecture at simulated environment of Ericsson with 222225 connection items from 9000 base stations all over the world. Each connection item has a complete UE session and one of possible connection statuses, e.g. active, inactive, connected, DRX sleeping, postponed. These connection items can be from any country in the world. Methods. We design a new architecture for UPCUL component of LTE network based on analysis of real network data from Ericsson. We perform a case study to develop and evaluate the new architecture at Ericsson. Results. We evaluate the new architecture by performing a case study at Ericsson. The results of case study show that the new architecture not only increases DSP utilization by 35%, but also decreases signal operational latency by 53%, FO operation time by 20% and FO operation cycles by 20%. Also, the new architecture increases correctness performance. Conclusions.  We conclude that the new architecture increases DSP utilization and decreases the signal operational latency, therefore, improves performances of UPCUL component of LTE.  Due to time constraints, we only considered four LTE FOs (Function Objects) and relative signals. Future work should focus mainly on the other FOs and signals. We also analyze unconsidered FOs, and make an integration solution table which contains solutions to integrate these unconsidered FOs into the new architecture.  The second avenue for future work is to re-size the size of the two blackboard storages. We find out that the maximum memory size of needed UE sessions per sub-frame is only 1.305% of the memory size of all UE sessions (31650 bytes). So the memory size of blackboard storage should be adjusted on the basis of needed UE sessions instead of all UE sessions.
3

Analýza řídicích procedur v sítích EPS-IMS / Control Procedure Analysis in EPS-IMS Networks

Šubrt, Jan January 2017 (has links)
The master thesis is focused on control procedures in EPS-IMS networks. Firstly the thesis describes systems IMS and EPS. The second part of thesis includes the theory of control procedures in EPS such as cell acquisition, random access procedure, identification of subscriber, authentication of subscriber, security procedures, tracking area procedure, default bearer creation, implementation of CSFB procedure and detach procedure. Processes related to subsystem IMS such as registration to IMS, bearer creation for IMS signalling and voice service VoLTE are the next part of thesis. The next main topic is the VoLTE implementation problematic and VoLTE cooperation with diverse terminals. There is also explained the principle of Circuit Switched Fallback for realization voice services in EPS without VoLTE service. All procedures mentioned above except of procedures which are related to IMS were captured and analyzed using software Wireshark and QualiPoc. The final part of the thesis is lab task creation based of the analyzed messages.
4

Dynamic management of spectral resources in LTE networks / Gestion dynamique des ressources spectrales dans les réseaux LTE

Adouane, Amine Mohamed 16 February 2015 (has links)
La croissance exponentielle du nombre de dispositifs communicants et des services sans fils émergents fixe des objectifs toujours plus haut pour répondre à la demande de capacité sans cesse croissante des utilisateurs. Cela pose des défis constants pour atteindre les objectifs envisagés. La réutilisation spectrale élevée (High efficiency spectral reuse) a été adopté, cependant, elle conduit à des interférences accrues sur le réseau, ce qui dégrade les performances. L'OFDM (Orthogonal Frequency Division Multiplexing) est utilisé comme solution dans les réseaux de 4 G. Grâce à son orthogonalité, l'OFDM élimine l'interférence intra-cellulaire, mais l'interférence inter-cellule reste importante. Plusieurs méthodes connues sous le nom d'Inter-Cell interférences coordination (ICIC) ont été proposées pour les diminuer. L'ICIC permet la gestion des ressources radio coordonnée entre plusieurs cellules appelées ENodeB. Ces eNodeB peuvent partager les informations nécessaires grâce à l'interface X2 qui les relient, ces informations sont transmises par des messages LTE normalisés. Lorsque les ENodeBs sélectionnent égoïstement les ressources, la théorie de jeux non-coopératifs est largement appliquée pour trouver un juste équilibre. Dans cette thèse, nous mettons l'accent sur l'ICIC pour la liaison descendante d'un système OFDMA cellulaire dans le contexte du projet SOAPS (Spectrum opportuniste accès à la Sécurité publique). Ce projet a pour but l'amélioration de la planification des ressources de fréquences pour fournir des services à large bande dans les systèmes PMR (radiocommunications mobiles privées) en utilisant les technologies LTE. Nous adressons le problème d'ICIC en proposant quatre solutions différentes sous forme d'algorithmes entièrement décentralisés, ces algorithmes se basent sur la théorie des jeux non-coopératifs avec des équilibres de Nash purs des jeux considérés / The exponential growth in the number of communications devices has set out new ambitious targets to meet the ever-increasing demand for user capacity in emerging wireless systems. However, the inherent impairments of communication channels in cellular systems pose constant challenges to meet the envisioned targets. High spectral reuse efficiency was adopted as a solution to higher data rates. Despite its benefits, high spectral reuse leads to increased interference over the network, which degrades performances of mobile users with bad channel quality. To face this added interfence, OFDM (Orthogonal Frequency Division Multiplexing) is used for the new 4th generation network. Thanks to its orthogonality OFDM eliminates the intra-cellular interference, but when the same resources are used in two adjacents cells, the inter-cell interference becomes severe. To get rid of the latter, several methods for Inter-Cell Interference Coordination (ICIC) have been proposed. ICIC allows coordinated radio resources management between multiple cells. The eNodeBs can share resource usage information and interference levels over the X2 interface through LTE-normalized messages. Non-cooperative game theory was largely applied were eNodeBs selfishly selects resource blocks (RBs) in order to minimize interference. In this thesis, we stress on ICIC for the downlink of a cellular OFDMA system in the context of the SOAPS (Spectrum Opportunistic Access in Public Safety) project. This project focuses on the improvement of frequency resource scheduling for Broadband Services provision by PMR (Private Mobile Radio) systems using LTE technologies. We addressed this problem with four different solutions based on Non-cooperative game theory, three algorithms are devoted to RB selection in order to manage the interference, while the last one is a power control scheme with power economy and enhanced system performances
5

Rádiová přístupová síť mobilní sítě / Radio Access Network of a Cellular Network

Duda, Michal January 2016 (has links)
The aim of the work is the radio access network of mobile networks second, third and fourth generation. The main objective is a description of the radio access network of the second, third and fourth generation, their elements, interfaces and signaling procedures. The next part describes the emergency services and the architecture of the fourth generation mobile networks. The practical part is then devoted to identify actions needed to prepare radio access network to testing emergency services, identify actions needed to conversion of transport protocol fixed part of the radio access network from IPv4 to IPv6 and describe the intervention to radio access network to change the active segment of the core network.

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