National Repository of Grey Literature 95 records found  beginprevious86 - 95  jump to record: Search took 0.00 seconds. 
Design and development of application for position monitoring
Kovář, Petr ; Šilhavý, Pavel (referee) ; Krajsa, Ondřej (advisor)
The aim of the master’s thesis was to implement in the C++ language a software solution of the localization of the mobile phone with Symbian OS in the GSM network. The intended purpose of this solution would be especially the phone localization in the case of its theft or loss. A familiarization with the development process of the Symbian platform and understanding the features of the Symbian version of the C++ language preceded the realization itself, because the Symbian C++ has an original style of the memory manipulation and error handling. The Symbian C++ basic principles and its features used in the implemented software are described in the second chapter of the text part, the first chapter deals with the history and version structuring of the Symbian OS. In the third part of the text is described the created software. The realized solution consists of three parts – server application PhoneLocServer for a mobile device, client application PhoneLocClient for a PC and the web-located part. The server was developed for the Symbian OS in the C++ language in the IDE Carbide.c++ and was tested in the S60 3rd edition SDK MR emulator and on the real device Nokia N73. It is a GUI-less application running in the background, which is run automatically after a smartphone start-up. It controls the incoming SMS over the socket listening and the messages addressed to itself processes before a user can notice them. The control messages body is comprised of a prefix, which identifies them, a password, a sending period value and a state to which application should change. After the receiving of the control SMS server verifies the SMS sender through the use of his telephone number and the password. It compares these values with the data stored for the given IMEI on the web server. If the verification succeeds, the server runs a timer with the period known from the control SMS and on the callback of this timer are transferred the data describing current phone location and state via HTTP protocol to the web server. The GSM localization method “Cell ID” is used for the location determination. After the client user asks for the start of loading the data, he must answer the password and the observed phone’s IMEI and he is verified through the use of the web server again. If the verification succeeds, the periodic download of the server data starts and from the first downloaded file is found out the upload period. Download then continues till the time the client detects the end of sending by the server part or till the client user stops the download himself. The client was developed in the C++ language in the C++ Builder environment. It requires a Windows OS and internet connection for its right function. The web server mediates communication between the server and the client, stores the data for user verification and makes possible the server-side upload by the help of a simple PHP script. In all the used web server directories is present the .htaccess file to improve its security, e.g. it denies the directory listing in a web browser.
Turbo codes and their applications
Ploštica, Stanislav ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
This Diploma thesis aims to explain the data coding using turbo codes. These codes belong to the group of error correction codes. We can reach the high efficiency using these codes. The first part describes process of encoding and decoding. There are describes parts of encoder and decoder. Principle of encoding and decoding demonstrate a simple example. The end of this part contains description of two most frequently used decoding algorithms (SOVA and MAP). The second part contains description of computer program that was made for using as teaching aid. This program was created in Matlab GUI. This program enables to browse error correction process step by step. This program contains graphic interface with many options and display results. In the third part is described program created in Matlab Simulink that was implemented into the TMS320C6713 kit and there is description of measuring procedure. For verification of efficiency of turbo codes was measured any parameters. Some of these parameters are: number of decoding iterations, generating polynoms and using of puncturing. The last part contains measured value and result evaluation.
Universal mobile communication platform using the bluetooth technology
Sopko, Richard ; Šilhavý, Pavel (referee) ; Daněček, Vít (advisor)
This master’s thesis is focused on field of communication technologies in mobile devices in personal WPAN type wireless networks. Work consists of three basic parts. First part provides overview of personal WPAN wireless networks and is specialized on Bluetooth technologies and its opportunities of communication between mobile devices. Second part deals with an opportunity of using programming language Java 2 Micro Edition in work with Bluetooth technology. Key point of this work is third part which includes scheme of conception of a communication platform and creating of application designed for mobile phones. Created application enables communication by means of changing files and written conversation of two or more people in real time by Bluetooth connection.
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.
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.
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.
Optimization of digital switching fields
Mikéska, Marek ; Šilhavý, Pavel (referee) ; Kapoun, Vladimír (advisor)
The diploma thesis is focused on the features description of electronics switches for digital switching arrays and on the design of program for optimal calculation of switching points and the figure of switches in digital switching arrays investigation. The electronics switches types, used for time circuit separation, are described in the preamble. These switches are the base of digital switching arrays and in principal two types are defined: the switch S and switch T. The switch S allows the interconnection only of the same channel intervals from incoming circuit with random outgoing circuit. The switch S is being used in multistage switching arrays in combination with the switches T because it can not be used separately. The switch T allows exchanging the time position of incoming circuit to different time position of outgoing circuit depending on connection needs. The time switch can substitute the space switch under specific work conditions. In practice, the time switch with controlled reading and writing is used. The following part of diploma thesis is focused on the designs and calculations of optimal switching points of digital switching array which is the executive unit of switching systems. These systems directly interconnect the signals from digital multiplexes and make the basic assumptions for telecommunication networks integration. The digital switching array means the equipment which is able to connect the channels of digital multiplexes carrying the information in encoding form. The multiplexes are the most often with pulse coded modulation or adaptive delta modulation. The digital switching arrays are divided into the time and space one. The switching arrays of digital switching systems can be made by time switching array T whose realization is limited to specific capacity or by the connection of multistage arrays. Single stages sequenced one behind each other are made by the switches T and S. The space array S does not allow making the digital switching array of switching centre. The program which determines possible proposals of switching arrays from defined figure of inputs and calculates the optimal figure of switching points and switches is a part of diploma thesis.
Design of digital switching field animation
Kučerka, Daniel ; Šilhavý, Pavel (referee) ; Kapoun, Vladimír (advisor)
This thesis describes types and parameters of memories used in communication engineering. The memory is a device which is able to record and to save information for the certain period of time. The memory is used in computers, measuring devices, consumer electronics etc. Main parameters of the memory are capacity, data stream speed, price of bit and time of memory cycle. The first part of this thesis deals with two types of memory – external and internal. External memories are removable media such as discs and magnetic tapes used for information saving and data backup for longtime period. Inner memories – in the form of semiconductive components – are mostly attached to the main panel. There are two types of inner memories – RAM (random access memory) and ROM (read only memory). The memories could be further divided according to their dependence on feeding used for memory saving. Types of memories used in switching exchanges are also mentioned in this part. The next part discusses the scheme of T switch for the first level of European PDH E1. The space switch and the time switch T belongs to switches used in digital switching exchange. In this part, the T switch, in particular the switch TR with controlled reading and the switch TW with controlled writing are described into details such as its parameters and methods of control. Furthermore, the calculation of call memory and control memory extant in E1 and E2 hierarchy are presented as well as the memory reading time and writing time of T switch in E1 and E2 hierarchy. The result of this thesis is a design of digital switching field animation that consists of four T switches. All operations, which are used in building linking of digital switching field, are shown in this animation.
Algorithms for decoding the Reed-Solomon error control code
Tieftrunk, Tomáš ; Číž, Radim (referee) ; Šilhavý, Pavel (advisor)
Thesis discuss about effort to ensure from error, which may occur during transmission over noisy channel. There's used Reed Solomon code. It's block, cyclic and systematic code, which is symbol orientated. Computational process of decoding is mathematically time-consuming. In thesis is closely described Berlekamp-Masey algorithm, used in decoding to evaluate error polynomial. Process is illustrated in application in Matlab. Practical realization uses Reed Solomon code in communication over RS232. Communication is established between computer and microcomputer.
Uninterruptible power supply with management system utilizing I2C bus for medical devices
Daněček, Vít ; Hanák, Pavel (referee) ; Šilhavý, Pavel (advisor)
Object my master’s thesis is the design a Medical device uninterruptible power supply with managment system utilizing I2C bus. Norm EN 61000-3-2 define electric parameters for medical device power supply. In case of power supply for medial equipment is expressive accent on increased electric strength. This power supply have usually primary and secondary power circuit. Primary power circuit form line accumulator, which supplies needed output to the load and recharge reserve battery. Secondary is formed battery-pack, which serve as back-up power supply at drop-out prime circle. They have a minimum weight, small proportions, large overall effectivity also charging battery-pack and monitoring battery-pack charging condition. Result whole those master’s thesis is design Medical device uninterruptible power supply with managment system utilizing I2C bus and realization board layout. Resulting characteristics designed supply unit are: Output voltages are 5V/ 3 A , 12V/ 1,5 A and -12V/ 0,1 A. Managment support information about: Line adapter/ battery pack switch, battery-pack charging condition and actuall tempera-ture battery-pack.

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