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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

IP Multimedia Subsystem / IP Multimedia Subsystem

Bendíček, Martin January 2008 (has links)
This Master’s thesis deals with IMS architecture problems. This thesis describes its creation and progress, also structure of this architecture is mentioned. Text of this thesis describes function of the most important parts of the architecture, such as Proxy-CSCF, Interrogating-CSCF, Serving-CSCF and HSS. IMS architecture uses SIP protocol for establishment, maintenance and closing session and Diameter protocol for network management functions. That is why this thesis also describes characteristics of these two protocols. Next part of the thesis is focused on Open-source platform Open IMS Core and its installation. Open IMS Core platform was developed for testing IMS technologies within an internal project at the Fraunhofer Institute FOKUS in Berlin. Nowadays it is used by major part of vendors and providers for testing their products and services. As a main theme of this thesis, there was made a simple network, which consists of three users. This network is established on fundamentals of IMS and it was made in Open IMS Core. So in one chapter is outlined a process of its creation. There is described a process of adding a user list to database server HSS. In the next part there are mentioned some information about setup of virtual IMS terminal. Eventually there are shown some possibilities of how to catch traffic in the network. In this chapter there are also state diagrams, which describe a process of registration of IMS terminal and also a process of establishment, maintenance and closing session.
62

Implementation and Analysis of VoIP CPE Management System using TR-069

Darwis, Darwis January 2008 (has links)
Customer Premises Equipment (CPE) management is underestimated by the CPE vendors and services providers while it is in fact one of the most important aspects to ensure the high quality of service. Many people still think CPE management is the same as network management. Thus, they use the Simple Network Management Protocol (SNMP) to manage their CPEs. However, SNMP alone was thought not to scale nor to support the provisioning of the types of services which internet services providers must support today. This thesis highlights the importance of CPE management, how it is implemented using the TR-069; a CPE management protocol defined by the DSL Forum, and how a management system can be used for VoIP service management, and whether a CPE should implement TR-069 or SNMP as the management system to support. In the addition, the TR-069 will be compared against the SNMP to determine which one is more suitable for CPE management. An interesting conclusion is that while TR-069 does have some advantages over SNMP for managing services rather than simply managing the device, these advantages are not a large as initially believed nor has TR-069 avoided the problem of proprietary management information which SNMP has demonstrated. / Customer Premises Equipment (CPE) skötseln är undervärderad av CPE försäljarna och tjänste leverantörerna meddans det faktiskt är en av de mest viktiga aspekterna för att tillförsäkra hög quality of service. Många personer tror fortfarande att CPE skötseln är det samma som att sköta ett nätverk. Så, de använder Simple Network Management Protocol (SNMP) för att sköta deras CPE:er. Emellertid, SNMP ensamt var inte tänkt att skala eller att ge stöd vid försörjning av typer av tjänster som internet tjänst leverantörer måste stödja idag. Den här avhandlingen framhäver det väsentliga med CPE skötsel, hur det implementeras vid användande av TR-069; ett CPE skötsel protocol definerat av DSL forum, och hur detta administrations system kan användas för att sköta VoIP tjänster. Tilläggande så kommer avhandligen att jämföra TR-069 och SNMP för att bestämma vilken av dem som är mer lämplig för CPE administration. En intressant sammanfattning är att meddans TR-069 har några fördelar över SNMP för att sköta tjänster hellre än att enkelt sköta enheten, dessa fördelar är inte så stora som man trott från början. Dessutom, TR-069 ser inte ut att kunna övervinna problemet med privatägd (användande av privat MIB) information som SNMP har demonstrerat.
63

RANGE AND SPACE NETWORKING - WHAT’S MISSING

Rash, James, Hogie, Keith, Criscuolo, Ed, Parise, Ron 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A large selection of hardware and software components are readily available for supporting Internet communication in the ground network environment. These components can be used to construct very powerful and flexible communication systems. The Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC has been defining and demonstrating ways to use standard Internet technologies for future space communication. Theses concepts and technologies are also applicable to test range telemetry applications. This paper identifies the network equipment and protocols to support end-to-end IP communication from range sensors and spacecraft instruments to end users. After identifying the end-to-end network hardware and software components, the paper discusses which ones are currently available and lists specific examples of each. This includes examples of space missions currently using Internet technology for end-to-end communication. It also lists missing pieces and includes information on their current status. The goal of this paper is also to stimulate thought and discussion on what steps need to be taken to start filling in the remaining missing pieces for end-to-end range and space network connectivity.
64

SPACE COMMUNICATION DEMONSTRATION USING INTERNET TECHNOLOGY

Israel, Dave, Parise, Ron, Hogie, Keith, Criscuolo, Ed 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of Internet communication technologies to space communication. The goal is to provide global addressability and standard network protocols and applications for future space missions. It describes the communication architecture and operations concepts that will be deployed and tested on a Space Shuttle flight in July 2002. This is a NASA Hitchhiker mission called Communication and Navigation Demonstration On Shuttle (CANDOS). The mission will be using a small programmable transceiver mounted in the Shuttle bay that can communicate through NASA’s ground tracking stations as well as NASA’s space relay satellite system. The transceiver includes a processor running the Linux operating system and a standard synchronous serial interface that supports the High-level Data Link Control (HDLC) framing protocol. One of the main goals will be to test the operation of the Mobile IP protocol (RFC 2002) for automatic routing of data as the Shuttle passes from one contact to another. Other protocols to be utilized onboard CANDOS include secure login (SSH), UDP-based reliable file transfer (MDP), and blind commanding using UDP. The paper describes how each of these standard protocols available in the Linux operating system can be used to support communication with a space vehicle. It will discuss how each protocol is suited to support the range of special communication needs of space missions.
65

INTERNET TECHNOLOGY FOR FUTURE SPACE MISSIONS

Rash, James, Hogie, Keith, Casasanta, Ralph 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Ongoing work at National Aeronautics and Space Administration Goddard Space Flight Center (NASA/GSFC), seeks to apply standard Internet applications and protocols to meet the technology challenge of future satellite missions. Internet protocols and technologies are under study as a future means to provide seamless dynamic communication among heterogeneous instruments, spacecraft, ground stations, constellations of spacecraft, and science investigators. The primary objective is to design and demonstrate in the laboratory the automated end-to-end transport of files in a simulated dynamic space environment using off-the-shelf, low-cost, commodity-level standard applications and protocols. The demonstrated functions and capabilities will become increasingly significant in the years to come as both earth and space science missions fly more sensors and the present labor-intensive, mission-specific techniques for processing and routing data become prohibitively. This paper describes how an IP-based communication architecture can support all existing operations concepts and how it will enable some new and complex communication and science concepts. The authors identify specific end-to-end data flows from the instruments to the control centers and scientists, and then describe how each data flow can be supported using standard Internet protocols and applications. The scenarios include normal data downlink and command uplink as well as recovery scenarios for both onboard and ground failures. The scenarios are based on an Earth orbiting spacecraft with downlink data rates from 300 Kbps to 4 Mbps. Included examples are based on designs currently being investigated for potential use by the Global Precipitation Measurement (GPM) mission.
66

Using link layer information to enhance mobile IP handover mechanism : an investigation into the design, analysis and performance evaluation of the enhanced mobile IP handover mechanism using link layer information schemes in the IP environment

Alnas, Mohamed Jimaa Ramadan January 2010 (has links)
Mobile computing is becoming increasingly important, due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. We have also seen a steady growth of the market for wireless communication devices. Such devices can only have the effect of increasing the options for making connections to the global Internet. The Internet infrastructure is built on top of a collection of protocols called the TCP/IP protocol suite. Transmission Control Protocol (TCP) and Internet Protocol (IP) are the core protocols in this suite. There are currently two standards: one to support the current IPv4 and one for the upcoming IPv6 [1]. IP requires the location of any node connected to the Internet to be uniquely identified by an assigned IP address. This raises one of the most important issues in mobility because, when a node moves to another physical location, it has to change its IP address. However, the higher-level protocols require the IP address of a node to be fixed for identifying connections. The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet Engineering Task Force (IETF) that addresses this issue. It enables mobile devices to stay connected to the Internet regardless of their locations, without changing their IP addresses and, therefore, an ongoing IP session will not be interrupted [2, 3, 4]. More precisely, Mobile IP is a standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher-level protocols like TCP. However, before Mobile IP can be broadly deployed, there are still several technical barriers, such as long handover periods and packet loss that have to be overcome, in addition to other technical obstacles, including handover performance, security issues and routing efficiency [7]. This study presents an investigation into developing new handover mechanisms based on link layer information in Mobile IP and fast handover in Mobile IPv6 environments. The main goal of the developed mechanisms is to improve the overall IP mobility performance by reducing packet loss, minimizing signalling overheads and reducing the handover processing time. These models include the development of a cross-layer handover scheme using link layer information and Mobile Node (MN) location information to improve the performance of the communication system by reducing transmission delay, packet loss and registration signalling overheads. Finally, the new schemes are developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of these schemes.
67

IPv6@HH   Campus Network Design / IPv6 @ HH

Munir, Sarmad, Habib, Yasir, Javed, Sheraz January 2011 (has links)
The aim of this thesis project to design and implement a campus network based on IPv6, as IPv6 is the protocol of the future communication.There are many papers available which discuss upgrade from IPv4 to IPv6 and their side by side implementations and functionalities. Contrary to this we are working on running a network entirely based on IPv6. So we built this network infrastructure, monitored it and tested it.A network working on IPv6 is not just about a different addressing plan. Rather there are some serious questions. Network administrators are quite happy and comfortable with the current setup of IPv4. Would this IPv6 be able to provide them same facilities on one-to-one basis? If not, would it be upgrade or degrade on some functionality? Is there solution to every problem available or they would have to discover it themselves? All these and many more questions were faced and tackled in the course of this thesis.
68

Contributions pour la réduction du temps de zapping dans un réseau IPTV Multicast / Contributions for the zapping time reduction in IPTV Multicast network

Sarni, Mounir 14 December 2010 (has links)
Cette thèse concerne l'investigation détaillée du problème du temps de zapping dans les réseaux d'opérateurs offrant un service IPTY basé sur la technologie multicast. Cette investigation a conduit à plusieurs contributions qui permettent de substantiellement améliorer le temps de zapping dans ce type de réseau. Notre première contribution concerne la partie purement réseau. Nous avons proposé d'optimiser le processus de changement de chaîne et ceci pour chaque version du protocole IGMP. Cette optimisation réduit la latence due au réseau sans pour autant augmenter la consommation de bande passante d'une manière significative. Nous avons modélisé le service IPTV Multicast pour estimer les pics de consommation de la bande passante pour permettre à l'opérateur de dimensionner son réseau. La deuxième contribution concerne la partie traitement du flux IPTV par le récepteur. Dans cette partie, nous avons proposé d'associer au flux principal un flux secondaire, version retardée du principal. La construction du flux secondaire se fait en donnant une priorité élevée aux paquets transportant des éléments d'une I-Frame par rapport à d'autres types d'éléments (P­ Frame, B-Frame, Voix et Data). Cette nouvelle règle de construction permet de réduire le délai d'attente de la première I­Frame nécessaire pour commencer la phase de décodage tout en réduisant le temps de remplissage du buffer. Dans un environnement réel, nous avons évalué cette contribution et constaté une réduction remarquable du temps de zapping. / This thesis involves a detailed investigation of the problem of IPTV zapping time in networks of operators providing IPTV service based on multicast technology. This investigation led to some contributions that can substantially improve the channel change time in this type of network.Our first contribution concerns the pure network. We proposed an optimization of the channels changing process for each version of the IGMP protocol. This optimization reduces network latency without significantly increasing the bandwidth consumption. We proposed also a model of multicast IPTV service that we used to estimate the maximum bandwidth demand. This model enables the operator to size the bandwidth availability in its network.The second contribution relates to the processing part of stream IPTV on the receiver. In this section, we proposed to combine the main flow to a secondary flow, delayed version of the main stream. The construction of the secondary stream is clone by giving high priority to packets carrying elements of an I-frame compared to other types of elements (P-Frame, B­-Frame, Voice and Data). This rule of construction can reduce the First I-Frame Delay required to start the decoding phase and at the same time reduce the Buffering Delay. In a real environment, we evaluated this contribution and measured a remarkable decline of the zapping time with our proposal.
69

Implementing security in an IP Multimedia Subsystem (IMS) next generation network - a case study

Unknown Date (has links)
The IP Multimedia Subsystem (IMS) has gone from just a step in the evolution of the GSM cellular architecture control core, to being the de-facto framework for Next Generation Network (NGN) implementations and deployments by operators world-wide, not only cellular mobile communications operators, but also fixed line, cable television, and alternative operators. With this transition from standards documents to the real world, engineers in these new multimedia communications companies need to face the task of making these new networks secure against threats and real attacks that were not a part of the previous generation of networks. We present the IMS and other competing frameworks, we analyze the security issues, we present the topic of Security Patterns, we introduce several new patterns, including the basis for a Generic Network pattern, and we apply these concepts to designing a security architecture for a fictitious 3G operator using IMS for the control core. / by Jose M. Ortiz-Villajos. / Thesis (M.S.C.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
70

Description multiple de l'information par transformation Mojette

Parrein, Benoît 22 November 2001 (has links) (PDF)
La représentation scalable de l'information s'impose aujourd'hui pour supporter l'hétérogénéité d'un réseau interconnecté tel que l'Internet. Le codage de source adopte, pour ce faire, une approche multi-résolution pouvant délivrer progressivement à un utilisateur le contenu de sa requête. Cependant, en supposant au cours de la transmission une gestion de bout en bout des priorités ainsi établies, ces schémas restent sommairement adaptés aux environnements de pertes de paquets et de qualité de service non garantie.<br />Les codages à description multiple offrent une alternative à la transmission hiérarchisée de l'information en brisant la scalabilité de la source aux abords du canal. Dans cette thèse, nous proposons une méthode originale de description multiple qui réalise une protection différenciée de chaque niveau hiérarchique de la source en fonction des propriétés dynamiques du canal de transmission.<br />La transformation Mojette (transformation de Radon discrète exacte) est une transformation unitaire qui permet de partager un volume de données en un ensemble plus ou moins redondant de projections équivalentes. L'évolution de ce type d'opérateur initialement utilisé dans un espace continu pour la reconstruction tomographique étend le concept de support d'image à celui de mémoire tampon géométrique pour données multimédias. Ce codage à description multiple, généralisé à N canaux, autorise la reconstruction de la mémoire initiale de manière déterministe par des sous-ensembles de projections dont le nombre caractérise le niveau de protection. Ce schéma est particulièrement adapté au mode de transport par paquets sans contrôle d'intégrité extensible du canal de transmission. La hiérarchie de la source est dans ce cas communiquée sous forme transparente pour le canal via des descriptions banalisées.<br />L'évaluation du codage est effectuée en comparant les débits engendrés avec ceux d'un code MDS (Maximum Distance Separable) qui fournissent une solution optimale dans le nombre de symboles nécessaires au décodage. La relaxation des propriétés MDS dans un code (1+ε)MDS avec la transformation Mojette demande une légère augmentation de débit au profit d'une complexité réduite.<br />L'application sur des schémas de compression d'images valide concrètement l'adaptation possible des sources actuelles à un canal de type best-effort. L'utilisation dans un environnement distribué (micro-paiement, stockage distribué de données multimédia) illustre en outre un partage sécurisé de l'information.<br />En perspectives de ce travail, nous avons abordé l'intégration de cette méthode dans un protocole de transmission scalable multimédia et étudié une version probabiliste du système.

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