|
|
Communication systems based on IP telephony
Zimek, Josef ; Kapoun, Vladimír (referee) ; Herman, Ivo (advisor)
My master’s thesis is focused on designing and creating communication network, which provides communication between two independent networks through encrypted tunnel. My solution is based on routers formed by older personal computers with FreeBSD like a operating system. Between routers is created static encrypted tunnel by using IPSec protocol. Voice services provides packet oriented exchange Asterisk with support of signaling protocol SIP. This solution can be used eg. for connecting remote branch to headquarters of company and then can branch utilize shrared resources. To headquarters can connect also remote workers from their home. In this case are used SSL certificates to authentication of user. This scenario is very required today.
|
|
|
Communication protocol implementation into signal processors
Červenec, Radek ; Daněček, Vít (referee) ; Herman, Ivo (advisor)
Práce se zabývá studují, modifikací a návrhem komunikačních protokolů a jejich implementací v digitálních signálových procesorech v jazyku instrukčních adres. Také zkoumá strukturu elektro-akustické jednotky EPIS 2.45. Popis jednotky je zaměřen na její softwarovou část a to zejména na operační systém založený na kooperativním multitaskingu. Pro dosažení úspěšného návrhu a implementace komunikačních protokolů se práce zaměřuje také na základy vícevrstvé síťové architektury. Poté je již zkoumána skutečná síť (Koris Net) společně s jejími, ale i dalšími komunikačními protokoly, jako například protokol Modus. Popis je doplněn o příklady zdrojového kódu jejich implementace v digitálním signálovém procesoru (ADSP 2191M). V práci je mimo jiné prezentován navržený komunikační protokol pro vyčtení souboru z palubního počítače připojeného k jednotce na sběrnici Modus. Společně s tím je také obsažena navržená úprava protokolu, tak aby bylo možné předávat stažené soubory přes radiové rozhraní do centrálního počítače.
|
|
|
Potentials of camera connection to PC computer
Pelc, Lukáš ; Růčka, Lukáš (referee) ; Herman, Ivo (advisor)
Bachelor thesis deals with the possibilities of network cameras and their connection to a PC. Network cameras are analyzed in terms of internal structure, external structure and aspects of their use. Communication with the PC and the user is provided with a communication interface and control software. The most important function in the use of network cameras is their output – a video. It is composed of several individual factors, such as the encoding method, compression and frame rate. The theory is applied in practice as proposed by the best camera, the method of connection and programming of custom control applications in the Java programming language.
|
|
|
Communication system for the blind - the mobile part
Dadák, Jiří ; Rampl, Ivan (referee) ; Herman, Ivo (advisor)
Orientation in big administration buildings can be very difficult for visually impaired people. Although most of the buildings are equipped with elevators, the buttons of which are designated with Braille characters and acoustic signals, it might be very difficult for the visually impaired to actually find the particular office. Even if there were descriptions in Braille at each office door, it would prove very complicating for the visually impaired individual to localize the descriptions in the first place, especially in case of a large number of offices in the building. That may also concern other important places, such as toilets, inside a building. In this thesis, I am going to present a design proposal of a communication system which uses transceivers placed at significant points in a building and receivers placed at the end of the white cane for orientation inside a building.
|
|
|
Communication devices over GSM/GPRS
Prečan, David ; Růčka, Lukáš (referee) ; Herman, Ivo (advisor)
This master thesis deals with a data remote transmission by means of SMS and GPRS technology. The overview of current solutions is presented and then a remote temperature measurement and a data transmission employing a communication module GSM/GPRS TM1 through GSM network using GPRS technology is described. As a response to an impulse, the communication module sends SMS. The technical solution is described in details including HW and SW design of the data transfer and processing equipment using a ATmega 162 microprocessor. This equipment communicates with a server (PC), which displays the measured temperature. A prototype which was used for a validation of the design is also described.
|
|
|
Communication protocol for built-in facilities
Dolák, Petr ; Burda, Karel (referee) ; Herman, Ivo (advisor)
Questions connected with communication technologies are really serious problem worldwide and this Bachelor’s thesis deals with this topic. Concretely is aim of this thesis Communication protocols. They are one of the basic keys in any data transfer, becausse they creates the basic environment for communication between users. First part of this thesis specifies nowadays used communication technologies, however range of Bachelor’s thesis do not give enough space for discussion all used technologies. The main aim of this part is to discuss used technologies on first three levels OSI model. It has been given to made a three layer solution and it has two possible results. In the second and third part has been this two results discussed, by realizing two differnet communication protocols. The first one deals with three lower levels of OSI model, and it is connected to non-error transfer and working with data. It means uploading and downloading them. Protocol build on higer levels of OSI model delas with good communication, however is more specified for services used by in-built units. The last part of this thesis includes diagrams and simulations performed in SDL language.
|
|
|
Processing of MP3 files for DSP
Římský, Adam ; Sysel, Petr (referee) ; Herman, Ivo (advisor)
This thesys is concerned with create of compressed .MP3 files and their conversion back into PCM format. I describe individual parts of these operations for their maximal understanding by reader. Next part is generally about properties of DSP, their architecture, computation possibilities and about properties of used product by Analog Devices. In last part is showed implantation of decoder in DSP architecture.
|
|
|
Algorithms of Electrical Drives State Estimation
Herman, Ivo ; Vavřín, Petr (referee) ; Václavek, Pavel (advisor)
This thesis deals with state estimation methods for AC drives sensorless control and with possibilities of the estimation. Conditions for observability for a synchronous drive were derived, as well as conditions for the moment of inertia and the load torque observability for both drive types - synchronous and asynchronous. The possibilities of the estimation were confirmed by experimental results. The covariance matrices for all filters were found using an EM algorithm. Both drives were also identified. The algoritms used for state estimation are Extended Kalman Filter, Unscented Kalman Filter, Particle Filters and Moving Horizon Estimator.
|
|
|
SIP/H.323 gateway with Asterisk PBX
Smékal, Lukáš ; Herman, Ivo (referee) ; Kovář, Petr (advisor)
This Bachelor’s thesis is engaged in problems of the internet telephony and its usage in today´s world, which offers many techniques how communicate among people. The internet telephony gives telephoning other format and shows new possibilities of IP protocol´s usage. The thesis is focused on the most used protocol corveying functions of VoIP technology, it is the standard H.323 and also the SIP protokol, which even if provides the same functions as H.323 is based on the different principle and because of its easy structure, it prepares good conditions for rise of new applications and services in internet telephony. In this thesis the Open Source private branch exchange Asterisk is also discussed. Asterisk, not only thanks to the usage of Voice over IP provides against the standard analogue private branch exchange many advantages and thanks to its modularity and expansibility also offers much more possibilities of configuration. The Session Initiation Protocol (SIP) is the basic protocol, with which Asterisk works. The standard H.323 is not implemented in the basic installation of Asterisk, therefore it is necessary to do its suitable installation and congiruation, in order to expand exchange´s functions for work with this standard and also to be able to realize translation between the protocol SIP and the standard H.323. The results, which I accomplished, are presented in the chapters „Dosažené výsledky“ and in the conclusion of the bachelor’s thesis.
|
|
|
The V-mux test system
Morávek, Patrik ; Herman, Ivo (referee) ; Novotný, Vít (advisor)
An optical network technology is the network technology that meets given requirements for a fast and reliable long-distance information transmission. Optical fibres can offer undoubted features where other communication technologies are near their limits or stand in front of insurmountable problems. The intensive research of last years is focused on optical transmission features utilization in the optimal way. Especially an optical signal processing in active network devices without a need for electrical conversation is a topic of high interest. V-Mux is an optical network device that accomplishes above mentioned requirements for modern optical network devices. It is a device that multiplexes and drops an optical signal in its native light form into or from optical fibre. Basic micro electro-mechanical components, which the V-Mux is built from, are high end precise devices. The whole complex V-Mux has to meet strict rules and specifications as the components itself. That is why a control system has to be included in the production process to keep quality and right functionality. This diploma thesis is focused on a development of the testing system that will help in the automated control procedure in the V-Mux production. A brief introduction to optical network technologies and a description of the GPIB bus form a first part of the thesis. The next part focuses on the V-Mux itself and the proposal of the test station with its component description. The last part deals with a developing of the software for the V-Mux testboard and a user application that will be used for the test system initialization.
|
guest ::
RSS feed.