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Multimedia networks in cars
Knopp, Petr ; Krajsa, Ondřej (referee) ; Koutný, Martin (advisor)
Moderní elektronika se stává nezbytnou součástí dnešních automobilů. Dynamicky se rozvíjející informační a telematické služby nacházejí široké uplatnění v automobilovém prostředí. Moderní aplikace vyžadují přenos velkého množství dat, což jim zajišťují dnešní komunikační protokoly. Cílem mé diplomové práce je analýza a návrh implementace multimediálních sítí do automobilů. Jednotlivé návrhy jsou charakterizovány a srovnány podle požadavků, kterým jsou v automobilovém prostředí vystaveny. Navržené topologie využívají nejen dnes používané technologie, ale jsou zde i návrhy, které nebyly dosud v automobilovém prostředí použity. Jednotlivé návrhy jsou srovnány a vyhodnoceny z pohledu automobilového výrobce.
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Signalling system No. 7 implementations for Asterisk
Janíček, Martin ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
Semestral project describes signaling system number 7, it's settings options and options of signaling over IP networks, especially two transport protocols SCTP and BICC for signaling SS7 over IP. Analyses kinds of implemetations of this signaling system to the Asterisk PBX with TDM E1 card support. Further part of this work is dedicated to the open source implementations libss7 of Digium and chan_ss7 which is currently developed by Dicea. Describes in detail their installation to the open source PBX Asterisk including testing of both and comparing these two open source solutions. Last part is focused on realization of gateway which converts communication from TDM network to IP network. For this part, three computers are used. First as SS7 signalling end softswitch, second as SIP signalling end softswitch and last as gateway between them. This gate works as interface between SS7 signalling and SIP signalling. Testing call was realized successfully for both directions.
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Narroband PLC model
Sekot, Karel ; Krajsa, Ondřej (referee) ; Mišurec, Jiří (advisor)
This thesis is focused on data communication utilizing low-voltage power distribution lines (PLC). It describes interference in narrowband systems commonly used for remote data collecting, for example. Preamble deals with basic priciples of PLC (signal injecting) and describes the measuring workplace, its wiring and used tools. Following sections define different types and possible sources of interference, operation of the equipment in terms of EMC and other characteristics of the transmission path. The text also analyzes practical interference tests, identifies main parameters affecting data transmision and compares teoretical and practical conclusions.
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Simulation of ADSL error protection systems
Bernat, Zbyněk ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
The main objective of this thesis was to create a model of forward error correction (FEC) system used in ADSL modem, which will be able to check its individual settings using the test methods specified in Recommendation G.996.1. The work is divided into two basic parts – theoretical and practical. The first part describes the basic functional characteristics of ADSL system, with attention being paid to aspects affecting the activity and setting of the error protection system. There are also discussed the theoretical basics of FEC coding techniques used in ADSL. The work also contains a description of the method for testing DSL system resistance against impulsive interference, which is specified in Recommendation G.996.1. The practical part of this thesis contains a description of the proposed model of the FEC system. The model was implemented in the programming environment Matlab Simulink. The proposed model includes the simulation of FEC coding process, DMT modulation and transmission channel with the impulse interference and the background noise. The proposed program is able to calculate parameters for setting FEC system from the specified data transfer rates and the requirement for interleaving. In addition, allows you to set the parameters of transmission line and sources of impulse interference and of the background noise. Under the set of input characteristics of the transmission is calculated bit allocation and the resulting parameters are given to a computational core of the model. In the application can be performed two types of test tasks. The first one is based on the Recommendation G.996.1 and makes it possible to determine probability of errored second. The second test task is for the measurement of resistance of the transmission system against impulsive interference. The results of the simulations are summarized in the conclusion of work.
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Monitoring of GSM network
Trávníček, Tomáš ; Krajsa, Ondřej (referee) ; Koutný, Martin (advisor)
This master’s thesis is focused on problems of monitoring GSM network using a mobile phone. Problems are analyzed on a theoretic basis with a description of available network parameters. Then the thesis offers a description of existing application environments providing a user with given data about the network. The main part of this work describes a development of application compiling queue data from mobile network and GPS, and creates output data illustrating signal strength in selected areas. The work also includes extensive measuring in select areas together with an evaluation of the processed data.
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Possibilities of connecting the Asterisk softswitch to the 4th generation PBX
Halamík, Zdeněk ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
This master’s thesis dissertate the possibilities of the linkage between Asterisk softswitch and the 4th generation private branch exchange. This should create a new generation’s network, so-called NGN, by the convergence of existing telecommunication networks with an IP computer network. This master’s thesis is divided into several chapters. In introduction is described the evolution of the private branch exchanges as well as the principles of the voice digitizing, codecs and signaling commonly used in both TDM and VoIP networks. The main aim of this project is the configuration of Asterisk software exchange for connection with PBX Alcatel 4400 as well as public phone network PSTN. Another goal of this master’s thesis was the configuration of Alcatel PBX and diagnostics of CCS and CAS signaling on E1 interface. In conclusion there are summarized advantages of NGN networks and their utilization in the future.
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Management and configuration of Asterisk VoIP exchange
Binder, Tomáš ; Krajsa, Ondřej (referee) ; Číka, Petr (advisor)
This diploma dissertation is dealing with the VoIP software exchange Asterisk. In the dissertation there are described its abilities and possible ways of its configuration. Special attention is given to the signalling protocol SIP, which is described in one of the chapters. Within this dissertation a dial plan, which demonstrates the technique of dial plan creating, was created. Within the boundaries of the dialplan following services could be found: a voicemail, conference, Interactive Voice Response and call queues. Configuration files, with the help of which the exchange is configurated, are described in my dissertation as well. Finally, three laboratory assignments for purposes of the subject Multimedia Services are mentioned. Their main aim is to familiarise students with the creation of SIP accounts in the exchange, their mutual connections, defining the Interactive Voice Response and forming a new call centre.
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