Diplomová práce popisuje VoLTE službu, vývoj a nasazení LTE (zaváděcí fázi, skutečný LTE stav a výhledy do budoucna atd.), EPC-IMS architekturu (popis funkce uzlu, rozhraní atd.) Komunikace mezi uzly a funkce, rozhraní a protokoly jsou používány v průběhu signalizace (SIP SDP) a datový tok (RTCP RTP). Práce stručně popisuje základní toky hovorů, typy nosičů (GBR and N-GBR), a to vytvoření / mazaní nosičů během komunikace. Další část diplomové práce o implementaci volte, instalace a konfigurace IMS. Závěrečná část diplomové práce popisuje zkoušky sítě a, analýzu protokolu.

Diplomová práce popisuje VoLTE službu, vývoj a nasazení LTE (zaváděcí fázi, skutečný LTE stav a výhledy do budoucna atd.), EPC-IMS architekturu (popis funkce uzlu, rozhraní atd.) Komunikace mezi uzly a funkce, rozhraní a protokoly jsou používány v průběhu signalizace (SIP SDP) a datový tok (RTCP RTP). Práce stručně popisuje základní toky hovorů, typy nosičů (GBR and N-GBR), a to vytvoření / mazaní nosičů během komunikace. Další část diplomové práce o implementaci volte, instalace a konfigurace IMS. Závěrečná část diplomové práce popisuje zkoušky sítě a, analýzu protokolu.

One of causes of increased latency service over the whole IMS network can be unbalanced SIP (Session Initiation Protocol) signalling traffic through CSCF (Call Session Control Function). This thesis is devoted to the proposal of weight-based load balancing algorithm which can be used for the S-CSCF assignment performed by I-CSCF during the initial registration procedure of subscribers over the IMS architecture. The designed mechanism is implemented and evaluated in the mathematical model of IMS subsystem based on single servers with FIFO queues with the unlimited capacity in the numerical computing environment - Matlab. Two test-cases with different performance conditions of available S-CSCFs are described. The influence of measured latency affected by performance of other nodes (e.g. P-CSCF, I-CSCF, HSS, etc.) is minimized. Each of simulated test-cases is measured with various service times of SCSCFs and inter-arrival times. The obtained results of designed algorithm are compared with well-known selection algorithm – the round-robin algorithm. It is shown that new selection mechanism improved the service latency of whole IMS network. The possible weakness of the designed weight-based algorithm is sensitivity to traffic model over the modelled IMS architecture.

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.

Mitte der 90er Jahre wurde an der TU Chemnitz ein XML-Dialekt und die zugehörigen Transformationstools für Lehrmaterialien entwickelt, die in internetbasierten Fernkursen eingesetzt wurde. In der Folge wurden weitere Kursskripte auf der Basis dieses Dialekts erstellt. Diese Materialien sollten auch nach der Einführung von OLAT weitergenutzt werden können. Deshalb wurden das Transformationswerkzeug zum Tool xml2lms angepasst und um folgende Funktionalität erweitert: - Verpacken des übersetzten HTML-Skripts in das IMS-CP-Format, - Extraktion von "Folien" für Präsenzveranstaltungen aus der XML-Quelle, - Erstellen eines druckbaren Skripts im PDF-Format. Geplante Erweiterungen sind die Darstellung von mathematischen Formeln mit dem math.js-Paket und das Generieren von PDF-Folien mit Hilfe der LaTeX-Beamer-Klasse.

The Session Initiation Protocol (SIP) is a signaling protocol for IP-based media services that will be the de facto standard for future media-over-IP services. Since SIP User Agents (UAs) support a limited number of service types (usually one or two), we assume that the future user will need to operate several UAs simultaneously. These UAs will constitute the user's personal service network. In this thesis, we investigate architectures for policy-based management of this network so that it can be used in an efficient manner. To achieve this, we propose a new SIP entity, called the SIP Service Manager (SSM), which lies in the core of the management system. Finally, we evaluate our proposal by implementing one version of the SIP Service Manager. / Session Initiation Protocol (SIP) är ett signaleringsprotokoll för IP-baserade mediatjänster som kommer att bli "de facto"-standard för framtida "media-över-IP"-tjänster. Då SIP User Agents (UAs) stöder ett begränsat antal typer av tjänster (oftast en eller två), antar vi att framtida användare kommer att behöva använda sig av flera UAs samtidigt. Dessa UAs utgör en användares personliga tjänstenätverk. I denna rapport, undersöker vi arkitekturer för policybaserad hantering (management) av detta nätverk, så att det kan användas effektivt. För att uppnå detta, föreslår vi en ny SIP-enhet, kallad SIP Service Manager (SSM), som är placerad i kärnan av hanteringssystemet. Slutligen utvärderar vi vår föreslagna lösning genom att implementera en version av en SIP Service Manager.

Market research reports by In-Stat, Gartner, and the Swedish Post and Telecom Agency (PTS) reveal a growing worldwide demand for Voice over IP (VoIP) and smartphones. This trend is expected to continue over the coming years and there is wide scope for mobile VoIP solutions. Nevertheless, with this growth in VoIP adoption come challenges related with quality of service and security. Most consumer VoIP solution, even in PCs, analog telephony adapters, and home gateways, do not yet support media encryption and other forms of security. VoIP applications based on mobile platforms are even further behind in adopting media security due to a (mis-)perception of more limited resources. This thesis explores the alternatives and feasibility of achieving VoIP security for mobile devices in the realm of the IP Multimedia Subsystem (IMS).

This dissertation focuses on the investigation of gas-phase characteristics of cucurbituril host-guest systems using ion mobility spectrometry (IMS) and related techniques. Collision cross-sections (CCS) of alkylammonium complexes of cucurbit[n]uril (CB[n]) are measured to understand the allosteric interactions that induce conformational changes in the complex in the presence of metal cations on one of the portals of the cucurbit[6]uril (CB[6]) host. Cationic species on one CB[6] rim sterically force longer linear alkylammonium guests out of the cucurbituril cavity during complex formation. Similarly, rigid cucurbituril-metal complexes were studied using IMS to demonstrate the effect of long-range ion-neutral interactions on the gas phase mobility of ions. The contributions of charge state and charge distribution to the ion mobility CCS measured using a drift tube ion mobility spectrometer (DTIMS) were studied. This IMS method characterization will help in the study of biomolecules and may answer some of the questions regarding CCS measurements in protein structures, that are still being debated. While most of the studies were done using an IMS system, this dissertation also includes gas phase characterization studies done using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. A novel gas-phase CCS measurement technique - cross sectional areas using Fourier transform ion cyclotron resonance mass spectrometry (CRAFTI) was attempted on bigger systems like the [cucurbit[6]uril-n-alkylammonium]+ complexes. Infrared multi-photon dissociation (IRMPD), collision induced dissociation (CID), and sustained off-resonance irradiation (SORI) studies were done on many CB[n] systems, which helped to extract useful structural information about the complexes.

Les réseaux mobiles ont un modèle en couches, avec: (1) un réseau d’accès IP offrant une connectivité IP aux utilisateurs; (2) une couche de contrôle de service, l’IMS; (3) une couche d’interaction pour le contrôle des politiques réseau, le PCC. Ce modèle, centralisé et hiérarchique, serait à l’origine de problèmes de passage à l’échelle et de qualité de service en cas d’explosion du volume de trafic de données à transporter. Dans cette thèse, un nouveau modèle pour les réseaux mobiles du futur est proposé: Ultra Flat Architecture (UFA). UFA utilise l’IMS pour le contrôle de tout type d’applications. UFA est dite plate car elle réduit le nombre de types de nœuds réseau à 2 principalement: (1) une Gateway UFA regroupant à la fois l’ensemble des fonctionnalités du réseau d’accès IP, de l’IMS et du PCC; (2) le terminal. Après la conception de l’architecture, nous avons spécifié et évalué trois procédures réseau principales pour UFA : l’enregistrement/authentification, l’établissement de service et la mobilité. Nous avons optimisé les deux premières procédures par rapport aux procédures standardisées de l’IMS. Par exemple, la procédure d’établissement de service présente un délai réduit et permet une configuration du service ou de la couche de transport selon les ressources disponibles dans le réseau. Nous avons développé une procédure de mobilité pour UFA, se basant sur le transfert, d’une Gateway UFA à une autre, des contextes de toutes les couches OSI liés au terminal, et sur la détermination proactive par la Gateway UFA des paramètres de toutes les couches du terminal. Tous les résultats obtenus montrent le grand intérêt d’UFA et des architectures plates plus généralement. / Mobile networks have a layered model, with: (1) an IP access network providing IP connectivity to users, (2) a service control layer, IMS, (3) an interaction layer for policy control, PCC. This model, centralized and hierarchical, will cause scalability and QoS problems in case of data volume explosion. In this thesis, a new model for future mobile networks is proposed: Ultra Flat Architecture (UFA). UFA uses IMS to control all application types. UFA is flat since it reduces the number of network node types to 2 mainly: (1) a UFA Gateway that includes the functions of the IP access network, the IMS and the PCC, and (2) a terminal. After designing the architecture, we specified and evaluated three main procedures for UFA: registration / authentication, service establishment and mobility. We have optimized the first two procedures compared to standard procedures of the IMS. For example, the service establishment procedure has a reduced delay and allows the configuration of the service or the transport layer according to the resources available in the network. We have developed a mobility procedure for UFA. It is based on the transfer, from one UFA Gateway to another, of the all OSI-layers contexts related to that terminal, and on a proactive determination of the all OSI-layers parameters, necessary for the terminal attachment to the new UFA Gateway. All obtained results show the great interest of UFA and of flat architectures more generally.

Denna studie har som syfte att bidra med nya kunskaper om specialpedagogiska stödinsatser som ges till nyanlända elever på gymnasieskolans introduktionsprogram språkintroduktion. För att göra det har en kvantitativ studie genomförts i vilken åtgärdsprogram har samlats in och granskats. En motivering till att göra studien var dels att det inte finns så mycket tidigare forskning inom området, dels att vissa studier visar att denna målgrupp av nyanlända inte får stödinsatser som är specifika för varje individ utan åtgärderna är generella. Då åtgärdsprogrammen var insamlade kartlades stödåtgärderna och rangordnades utifrån vilka som var mest frekvent förekommande. 40 åtgärdsprogram samlades in från sju utvalda gymnasieskolor. Antalet elever som läser på introduktionsprogram språkintroduktion har sjunkit och är i en stadig nedåtgående trend, vilket bekräftas i gymnasieskolornas statistik. Utifrån sammanställningen visar det sig att de specialpedagogiska insatser som är mest dokumenterade i åtgärdsprogrammen är anpassat schema och extra lektioner i svenska som andraspråk, därefter stöd av speciallärare i svenska och språkstöd av modersmålslärare. De förändringar av insats som dokumenterats i samband med uppföljning och utvärdering av åtgärdsprogrammen presenteras i uppsatsen. Slutsatsen är att de dokumenterade åtgärderna tyder på att elever på språkintroduktion behandlas som en homogen grupp med kollektiva lösningar vilket visar på ett kategoriskt perspektiv. Däremot visar analysen av förändringar av insatser på ett relationellt perspektiv på individens behov. Nyckelord: IMS språkintroduktion, nyanlända, specialpedagogiska stödinsatser, särskilt stöd, åtgärdsprogram.