Today's wireless transceivers require reference signals to translate received and transmitted signals to their desired frequencies. Therefore, they need frequency synthesizers which are typically based on phase-locked-loops (PLLs). Communication standards like GSM or Bluetooth necessiate that the PLLs put out oscillations with high spectral purity and accuracy. Additionally, the oscillation frequency must be adjustable very accurately at low transient time to account for occasional carrier frequency changes. So called Sigma-Delta-fractional-N frequency synthesizers are often employed to fulfil these requirements. However, the number and the locations of the poles of the control loop and hence the loop filter must be chosen properly. Unity gain frequency and phase margin have to be considered as well as the stringent frequency accuracy and the detailed origin of the spurious emissions. The design methodology proposed in this work is based on numerical optimization techniques, a high number of control loop poles and the use of Gm-C-biquads as loop filter building blocks.

Las redes de telecomunicaciones presentan elementos y funcionalidades comunes, las cuales en la actualidad tienden a converger hacia un componente común. Esta infraestructura colectiva permite proveer servicios de manera transversal a través de la red, sin importar la tecnología de acceso utilizada, ya sea telefonía móvil, telefonía fija o tradicional, redes de datos como Internet, u otras. En el caso de la telefonía móvil, la convergencia viene dada por la recomendación del grupo 3GPP (3rd Generation Partnership Group), la cual considera un núcleo de red basado en IP denominado IMS (IP Multimedia Subsystem). El objetivo general del presente trabajo de título es el diseño e implementación de una plataforma para la provisión de aplicaciones multimedia en redes convergentes, basada en software de código abierto, que permita el desarrollo fácil de servicios de valor agregado y se integre a las redes desplegadas en la actualidad. Además, se busca comunicar e integrar la arquitectura con un núcleo IMS, estudiando la conexión a la plataforma mediante terminales de distinta tecnología de acceso. En este trabajo se evalúan distintas alternativas de implementación para la plataforma. Las características de dichas opciones son comparadas a nivel de funcionalidades, eligiéndose OpenSER como el software a utilizar para desplegar la arquitectura. Variadas aplicaciones se implementan en el sistema, incluyendo la capacidad para realizar llamadas de voz tradicionales, el servicio de VoiceMail, un servidor de presencia, mensajería instantánea, Click-to-Dial, IPTV y el envío de SMS vía web. El siguiente paso consiste en integrar la arquitectura a un núcleo IMS, con tal de probar la interacción con las aplicaciones. Por último, se define y ejecuta un plan de pruebas, con el fin de certificar el funcionamiento de la plataforma de acuerdo a los estándares y garantizar su interoperabilidad con otros sistemas relevantes. Se concluye que es posible desplegar una arquitectura básica de servicios basada en software de código libre, lo que permite reducir significativamente los costos de implementación de una plataforma de aplicaciones ro busta y escalable. Se identifican también distintas interpretaciones de los protocolos, tanto en el núcleo de red como en los clientes, cobrando especial importancia el ajuste a los estándares para asegurar la compatibilidad entre plataformas y terminales de usuario. Por último, se presentan recomendaciones de trabajo a futuro basadas en los resultados de este proyecto.

No description available.

This thesis has investigated what different tools for static code analysis, with anemphasis on security, there exist and which of these that possibly could be used in a project at Ericsson AB in Linköping in which a HIGA (Home IMS Gateway) is constructed. The HIGA is a residential gateway that opens up for the possibility to extend an operator’s Internet Multimedia Subsystem (IMS) all the way to the user’s home and thereby let the end user connect his/her non compliant IMS devices, such as a media server, to an IMS network. Static analysis is the process of examining the source code of a program and in that way test a program for various weaknesses without having to actually execute it (compared to dynamic analysis such as testing). As a complement to the regular testing, that today is being performed in the HIGA project, four different static analysis tools were evaluated to find out which one was best suited for use in the HIGA project. Two of them were open source tools and two were commercial. All of the tools were evaluated in five different areas: documentation, installation & integration procedure, usability, performance and types of bugs found. Furthermore all of the tools were later on used to perform testing of two modules of the HIGA. The evaluation showed many differences between the tools in all areas and not surprisingly the two open source tools turned out to be far less mature than the commercial ones. The tools that were best suited for use in the HIGA project were Fortify SCA and Flawfinder. As far as the evaluation of the HIGA code is concerned some different bugs which could have jeopardized security and availability of the services provided by it were found.

This master thesis refers to a new technology in a mobil services IP multimedia subsystem. First, the theoreticl part, refers to the architectury of this technology and elementary protocols. Although it is real-time services, is nesessary to refer about the Quality of Services, that it ensures the condent transmition of data. The second, practisy part refers to a the development background SDS 4.0 FD1 from Ericsson ltd., that it is used develop aplications for IMS technology. It will be to develop the aplication , that it used to the IMS and it refers to the elementary function and comunication.

This thesis describes basic principles of IP Multimedia Subsystem, known as the IMS, and shows the possibility for design applications using IMS. Firstly, a generic architecture IMS as layer model divided into four logic layer with definition the interfaces and the main entities is described. The IMS is based on SIP and IP protocols. Then is the architecture of SIP with the main entities explained. Structure of packet, request and response method in the part of SIP is also described. After that, three network services, namely presence services, instant messaging services and push over cellular services are presented. For each services the figuration of their architecture and the basic definition of their main entities are shown. Moreover, the graphical diagrams of SIP signalization are depicted for these services. In the next chapter, the self implementation of services was designed, namely presence services and services for speech transmission with next secondary function as sending email with registration information of user. The project was designed as client - server application in the development studio SDS Ericsson 4.1. The client application was simulated as java application and also as an application for Symbian emulator. The process of client registration was performed with the help of ICP platform. Finally, the diagram of analysis communication client - server is displayed with the captured packets explanation by the help of network analyzer WireShark. The video files, which were specially created for this thesis showing presentations for presence services and sending email. The most important results are summarized in the end of this article.

Submitted work describes IMS (IP Multimedia Subsystem) and focuses on services offered by this technology. In the theoretical part of the thesis is a detailed description of the IMS architecture, in the terms of its components and interfaces. Also a SIP protocol is described as the main signalling protocol, which represents the basis of the IMS architecture and RTP protocol that allows the transmission of multimedia data in real-time. Further, there are provided services that the IMS system brings. The practical part of the work describes the design and implementation of services within the IMS. It is a client-server service. Server part of the system is implemented as a SIP Servlet application. It has access to the MySQL database, which stores records of multimedia files. Client registered in the IMS network can communicate with the SIP servlet sending a request for information on such files. Following this communication, the client can play the file in his online ICP application, or download it into his PC and then play. To play and view multimedia fines is used JMF. The service is implemented in a development environment SDS Ericsson 4.1, which allows simulation of the IMS network.

This master’s thesis is focused on the network architecture of IMS (Internet Protocol Multimedia Subsystem) and development an application for IMS. IMS architecture is the convergence of fixed and mobile networks. IMS enables rapid deployment of new multimedia services. In the first chapter is showed and described architecture IMS in four layers and block model of architecture IMS. Next chapter is focused to protocols, which are used in IMS. One of the most important protocols in network IMS is SIP. This protocol is analyzed in details. For development IMS platform application was used Ericsson SDS (Service Development Studio) in version 4.1. In SDS were created applications type of client and servlet. In this master’s thesis is also used development environment NetBeans. In NetBeans was created application for management of captured images. In the same development environment was developed application that shows the contents of a database. Last chapter is devoted to analyze individual parts of communication between client and servlet, and when client uses http to download image file.

This master’s thesis deals description of the IMS (Internet Protocol Multimedia Subsystem) and shows the possibility for design applications that using services this system. The theoretical part of the thesis is focused on a detailed description of the IMS architecture, its key components and the SIP protocol that is main signaling protocol in the IMS. The practical part of the work describes the design, implementation and test of the system for reservation of tickets to cinema in the IMS. The project was created as client-server application in the development studio SDS Ericsson 4.1 FD1 with built-in IMS simulator. The client application is designed for mobile devices with support of the J2ME platform. The server part of the system is realized as SIP Servlet with access to the MySQL database. In the database are saves records about registered users, offered tickets and successful reservation. For easy work over MySQL database of the system for reservation of tickets was created the application for its administration in the Java programming language (Java SE 6). With the assistance of this application, the operators of system can add and erase the records about films, time projection and disburse tickets on the basis of knowledge of reservation ID. In the end of the work is realized SIP signaling analysis of the client registration to IMS and communication between the client application and the SIP Servlet.

This thesis describes architecture of IMS and shows possibilities of IMS platform testing. Theoretical part describes layer model of the IMS as a whole and then describes it’s individual layers. Next chapters analyse key entities of the IMS, interconnection between reference points and features of protocols used in the IMS. Practical part deals with the introduction of Open IMS Core, which was chosen for the IMS technology testing. Settings necessary to carry out testing and interconnection between PBX Asterisk are shown in next chapters. After introduction of IMS desktop clients is carried out an instant messaging communication within the IMS network. The communication is captured and analysed by Wireshark application. Afterwards there is described how SIP protocol sends messages within the IMS. After a brief introduction to the PBX Asterisk, there are discussed assumptions for the interconnection between Asterisk and IMS. There are also described necessary settings needed for implementation and communication testing itself. The first test is an audio session carried out between the desktop IMS client and IP phone registered to the PBX Asterisk. Communication is captured for the analysis of preparation, conduction and termination of the session. After the successful realization of the audio call, video session has been made. The session was analysed in detail, including statistics of control signals and transmitted packets. There are two laboratory excercises in attachement of this thesis, which will help students to understand the IMS technology and communication options within the IMS network