Ces dernières années, les évolutions de linformatique et des télécommunications ont conduit à une modification drastique du paysage de la communication informatique, et en conséquence de lInternet et de ses services : les applications sont désormais à la fois multimédias, multi utilisateurs et coopératives ; les technologies réseaux offrent à présent de hauts débits de transmission, à échelle locale ou grande distance, et permettent de se connecter à lInternet via différents types de terminaux et de points daccès, filaires ou sans fil. En dépit de ces avancées, les services de communication offerts par lInternet sont encore très insuffisants, en ceci quils noffrent aucune garantie sur les performances offertes, notamment en termes de délai de bout en bout. Cest dans cette problématique que sinscrivent nos travaux, qui adressent le besoin de nouveaux services, protocoles et architectures de communication pour lInternet, dans le but doffrir des garanties de Qualité de Service (QdS). Notre démarche part dune expression formelle des besoins applicatifs et aboutit à des solutions de bout en bout visant à : (1) intégrer les niveaux considérés (Application, Transport et IP) ; (2) minimiser lutilisation des ressources (bande passante, buffer, &) ; et (3) abstraire le niveau applicatif de la complexité du choix et du paramétrage des services sous-jacents. Trois thèmes de recherche sont explorés : (1) les services et protocoles de Transport multimédia pour optimiser la QdS dans un contexte IP de type Best Effort ; (2) les architectures de bout en bout pour garantir la QdS, en coordonnant les nouveaux services de lInternet aux niveaux Transport et IP (IntServ et DiffServ mono puis multi domaines) ; et (3) la signalisation pour la QdS, dans un contexte IP de type DiffServ multi domaines. Notre prospective concerne dune part la signalisation pour la QdS en considérant à présent lhétérogénéité de lInternet multi domaines, et dautre part, les protocoles de Transp ort auto configurables et les architectures dynamiques, pour optimiser la qualité des communications et des coopérations dans les futurs réseaux ambiants (réseaux mobiles et ad hoc, capteurs, &) en tenant compte dune dynamicité du contexte à la fois au niveau utilisateur, mobile et coopérant, et au niveau du réseau, mobile et aux ressources variables. null null

在未來異質網路的整合環境中，QoS的問題益形重要，而以現今的網路環境而言，最有可能的異質網路整合是UMTS與WLAN。在本計畫中，我們將以UMTS與WLAN的異質網路整合環境作為基礎，提出Pricing-Improved QoS的觀念，結合Non usage-based pricing、Usage-based pricing、Static pricing和Dynamic pricing的優點以及DiffServ (Differentiated Services)劃分服務等級(service level)的機制，實際設計出使用者效用函數(utility function)與網路成本函數(cost function)，並以分級訂價方式訂定價格。藉著價格機能，讓使用者表達其對服務等級的需求或期望，並使網路資源適當地分配給各種服務，避免資源浪費或錯置的情形，以符合QoS的需求並提高整體社會福利及增加廠商收益。 / The issue of QoS is getting more and more important in the future integration of heterogeneous networks, and the most feasible integration is UMTS and WLAN as for present network environment. In our research, we would propose the concept of pricing-improved QoS combined with the advantage of usage-based, non usage-based, static, and dynamic pricing schemes and the mechanism of differentiated service classess of DiffServ (Differentiated Services) based on the integration of UMTS and WLAN. We would propose the utility function and cost function in detail, and price by differentiated service classes. By the affection of price, a user could express the service class he actually needs and expects. Network resources would be allocated appropriately to each service class avoiding the inappropriate allocation and wastage. This would meet the requirement of QoS and improve the providers’ revenue and overall social welfare.

Made available in DSpace on 2016-08-17T14:52:53Z (GMT). No. of bitstreams: 1 Ricardo Henrique Bezerra Azoubel.pdf: 588389 bytes, checksum: 40c0c99f808c27d0a6967b9d18c9c22a (MD5) Previous issue date: 2004-09-24 / This work presents a platform of tests (testbed) inexpensive, constructed in a controlled environment composed by microcomputers and free softwares. It is implemented, in such platform, the differentiated service model (DiffServ), with expedited forwarding (PHB EF). It is basically considered, from the collection of metrics main of QoS (delay, jitter, loss and throughtput), the performance analysis of voice characteristic traffics, when submitted to experimental tests in some scenes and conditions. Initially, in an environment capable to differentiate traffics, flows generated by standardized voice coder/decoder (G.711 and G.726) are modeled, in which the packets size and the amount of aggregate flows are varied, in scenes with and without QoS. It is compared, after that, the behavior of flows generated by activity-silence (ON-OFF) and continuous (CBR) sources. Can be perceived in this study how much the packets size variation influence in the performance of the most priority packets. It is carried, in the sequence, a specific analysis of the aggregation factor in flows generated by ON-OFF sources, in which can be observed the action of the basic principle of the model DiffServ, where aggregate flows receive differentiated treatment. It is studied, finally, through the use of transport protocols (UDP and TCP) and of elastic flows of FTP type, how much the best effort traffic confuses the performance of voice modeled flows. / Este trabalho apresenta uma plataforma de testes (testbed) sem custos, construída num ambiente controlado composto por microcomputadores e softwares livres. Implementa-se, em tal plataforma, o modelo de serviço diferenciado (DiffServ), com encaminhamento expresso (PHB EF). Propõe-se, fundamentalmente, a partir da obtenção das principais métricas de QoS (atraso, jitter, perda e vazão), a análise do desempenho de tráfego característico de voz, quando submetido a testes experimentais em vários cenários e condições. Inicialmente, num ambiente capaz de diferenciar tráfego, modelam-se fluxos gerados por codificadores/decodificadores de voz padronizados (G.711 e G.726), em que se varia o tamanho dos pacotes e a quantidade de fluxos agregados, em cenários com e sem QoS. Compara-se, em seguida, o comportamento de fluxos gerados por fontes atividadesilêncio (ON-OFF) e contínuas (CBR). Pode-se perceber nesse estudo o quanto a variação do tamanho dos pacotes impacta no desempenho dos pacotes mais prioritários. Realiza-se, na seqüência, uma análise específica do fator agregação em fluxos gerados por fontes ONOFF e observa-se a atuação do princípio básico do modelo DiffServ, onde fluxos agregados recebem tratamento diferenciado. Estuda-se, por fim, através da utilização de protocolos de transporte (UDP e TCP) e de fluxos elásticos do tipo FTP, o quanto o tráfego de melhor esforço impacta no desempenho de fluxos modelados de voz.

Made available in DSpace on 2016-08-17T14:52:57Z (GMT). No. of bitstreams: 1 Jose Coelho de Melo.pdf: 1424511 bytes, checksum: 76fbc2d3ff58f82123072e2b8323be1a (MD5) Previous issue date: 2005-03-14 / This work presents several ways of using mechanisms of Quality of Service (QoS) in networks hardwired for links of short band. It is demonstrated that the use of mechanisms of QoS brings profits of performance for priority applications and rationality in the use of band resources. The work is developed in a test platform of Previdência Social. Implementations of the PHBs EF, Afs and BE are tested. The work has evaluated the capacities to offer guaranteed band, traffic priority, conditioning of traffic and the impact of the competition between traffic classes. The experiments are mounted using the architecture of differentiated services (DiffServ) of platform Cisco, that is the standard in the network of the Previdência Social and are manipulated the mechanisms of classification, control of congestion, policing and conformation of traffic. The results give subsidy for implementation of some models of QoS in IP networks, mainly for those that serve short band. / Este trabalho apresenta diversas maneiras de utilização dos mecanismos de Qualidade de Serviço (QoS) em redes ligadas por enlaces de banda estreita. É demonstrado que o uso de mecanismos de QoS traz ganhos de performance aos aplicativos prioritários e racionalidade no uso de recursos de banda. O trabalho é desenvolvido em uma plataforma de teste que retrata um seguimento da rede da Previdência Social. São testadas possíveis implementações dos PHBs EF, Afs e BE. São avaliadas as capacidades de oferecer largura de banda garantida, priorização de tráfego, condicionamento de tráfego e o impacto da concorrência entre classes de tráfego. Os experimentos são montados utilizando a arquitetura de serviços diferenciados (DiffServ) da plataforma Cisco, que é o padrão na rede da Previdência Social, e são manipulados os mecanismos de classificação, controle de congestionamento, policiamento e conformação de tráfego. O resultado apresentado dá subsídio para implementação de vários modelos de QoS em redes IP, principalmente para redes servidas por banda estreita.

No description available.

The diploma thesis is focused on analysis and deployment of Quality of Services (QoS) in a computer network of The University of Economics in Prague (VŠE). The thesis describes the main QoS technologies focusing on technology Diffserv and its deployment with using available network devices in computer network of VŠE. In thesis the needs of network services and protocols for quality of services with division into different classes of services according to priority are discussed. The thesis explains the benefits and drawbacks of deploying QoS in the environment of VŠE with regard to wired and wireless network. In the practical part recommendations are applied to the production network and subsequently the benefits of modification are evaluated.

The aim of my diploma is to introduce the SNMP protocol designed for remote device management to the readers and present its implementation into the Opnet Modeler simulation environment. For the implementation the DiffServMIB database has been chosen, which describes the components of differentiated services mechanism. My diploma thesis describes in detail the possibilities of application of the DiffServMIB database in traffic management. The design of a simulation model, which represents the differentiated data processing in input and output direction on a router interface, is also introduced. Next, this model is implemented into the Opnet Modeler simulation environment. The goal of this simulation model is the possibility of simple configuration of individual MIB attributes. In my work I also suggest an implementation method able to interconnect the MIB database with the configuration process of the active network element - with focus on output procedures of DiffServ mechanism.

With the reality that diverse air interfaces and dissimilar access networks coexist, accompanied by the trend that dynamic spectrum access (DSA) is allowed and will be gradually employed, cognition and cooperation form a promising framework to achieve the ideality of seamless ubiquitous connectivity in future communication networks. In this dissertation, the cognitive gateway (CG), conceived as a special cognitive radio (CR) node, is proposed and designed to facilitate universal interoperability among incompatible waveforms. A proof-of-concept prototype is built and tested. Located in places where various communication nodes and diverse access networks coexist, the CG can be easily set up and works like a network server with differentiated service (Diffserv) architecture to provide automatic traffic relaying and link establishment. The author extracts a scalable '“source-CG-destination“ snapshot from the entire network and investigates the key enabling technologies for such a snapshot. The CG features provide universal interoperability, which is enabled by a generic waveform representation format and the reconfigurable software defined radio platform. According to the trend of an all IP-based solution for future communication systems, the term “waveform“ in this dissertation has been defined as a protocol stack specification suite. The author gives a generic waveform representation format based on the five-layer TCP/IP protocol stack architecture. This format can represent the waveforms used by Ethernet, WiFi, cellular system, P25, cognitive radios etc. A significant advantage of CG over other interoperability solutions lies in its autonomy, which is supported by appropriate signaling processes and automatic waveform identification. The service process in a CG is usually initiated by the users who send requests via their own waveforms. These requests are transmitted during the signaling procedures. The complete operating procedure of a CG is depicted as a waveform-oriented cognition loop, which is primarily executed by the waveform identifier, scenario analyzer, central controller, and waveform converter together. The author details the service process initialized by a primary user (e.g. legacy public safety radio) and that initialized by a secondary user (e.g. CR), and describes the signaling procedures between CG and clients for the accomplishment of CG discovery, user registration and un-registration, link establishment, communication resumption, service termination, route discovery, etc. From the waveforms conveyed during the signaling procedures, the waveform identifier extracts the parameters that can be used for a CG to identify the source waveform and the destination waveform. These parameters are called “waveform indicators.“ The author analyzes the four types of waveforms of interest and outlines the waveform indicators for different types of communication initiators. In particular, a multi-layer waveform identifier is designed for a CG to extract the waveform indicators from the signaling messages. For the physical layer signal recognition, a Universal Classification Synchronization (UCS) system has been invented. UCS is conceived as a self-contained system which can detect, classify, synchronize with a received signal and provide all parameters needed for physical layer demodulation without prior information from the transmitter. Currently, it can accommodate the modulations including AM, FM, FSK, MPSK, QAM and OFDM. The design and implementation details of a UCS have been presented. The designed system has been verified by over-the-air (OTA) experiments and its performance has been evaluated by theoretical analysis and software simulation. UCS can be ported to different platforms and can be applied for various scenarios. An underlying assumption for UCS is that the target signal is transmitted continually. However, it is not the case for a CG since the detection objects of a CG are signaling messages. In order to ensure higher recognition accuracy, signaling efficiency, and lower signaling overhead, the author addresses the key issues for signaling scheme design and their dependence on waveform identification strategy. In a CG, waveform transformation (WT) is the last step of the link establishment process. The resources required for transformation of waveform pairs, together with the application priority, constitute the major factors that determine the link control and scheduling scheme in a CG. The author sorts different WT into five categories and describes the details of implementing the four typical types of WT (including physical layer analog – analog gateway, up to link layer digital – digital gateway, up-to-network-layer digital gateway, and Voice over IP (VoIP) – an up to transport layer gateway) in a practical CG prototype. The issues that include resource management and link scheduling have also been addressed. This dissertation presents a CG prototype implemented on the basis of GNU Radio plus multiple USRPs. In particular, the service process of a CG is modeled as a two-stage tandem queue, where the waveform identifier queues at the first stage can be described as M/D/1/1 models and the waveform converter queue at the second stage can be described as G/M/K/K model. Based on these models, the author derives the theoretical block probability and throughput of a CG. Although the “source-CG-destination” snapshot considers only neighboring nodes which are one-hop away from the CG, it is scalable to form larger networks. CG can work in either ad-hoc or infrastructure mode. Utilizing its capabilities, CG nodes can be placed in different network architectures/topologies to provide auxiliary connectivity. Multi-hop cooperative relaying via CGs will be an interesting research topic deserving further investigation. / Ph. D.

La première partie de cette thèse est consacrée au problème de partage de ressources réseaux entre les flux multicast. Tout d'abord, nous proposons MFQ (Multicast Fair Queuing), un mécanisme simple de gestion active de files d'attente qui passe à l'échelle et permettant le partage équitable de la bande passante entre les flux multicast et ceci en utilisant une fonction d'équité configurée à l'avance. Ensuite, nous décrivons SBQ (Service Based Queuing), un ordonnanceur simple utilisant deux files d'attentes afin d'améliorer le partage de ressources entre les flux unicast et multicast. Une nouvelle méthode de re-marquage de paquets multicast dans un réseau DiffServ en se basant sur le nombre de membres est également proposée. Les performances de tous ces mécanismes sont évalués pour plusieurs configurations et trafics réels. Les résultats montrent que MFQ permet d'obtenir le partage de la bande passante entre les flux multicast attendu et que SBQ garantie une allocation équitable de ressources réseaux entre les flux unicast et multicast. Enfin, nous décrivons une extension du service multicast permettant le comptage de nombre de membres dans un groupe multicast aussi bien au niveau de la source multicast qu'au niveau des routeurs intermédiaires. La deuxième partie de cette thèse examine le problème de support de l'IP multicast dans les réseaux intégrant des supports de transmission hétérogènes. Dans une première étape, nous considérons les satellites GEO transparent et nous déterminons les adaptations qui doivent être ajoutées aux différents protocoles de routage multicast. Dans une deuxième étape, nous nous focalisons sur le déploiement de l'IP multicast dans la nouvelle génération de satellites GEO supportant les technologies des multiples sopt-beams et de la commutation à bord. Nous proposons une nouvelle méthode d'encapsulation optimisée pour l'IP multicast et nous développons deux approches permettant la commutation des paquets à bord du satellite: l'approche self-routing et l'approche label switching. Nous présentons le protocole SMRP (Satellite Multicast Routing Protocol) qui traite les messages PIM-SM messages reçus par le entités du système. À la fin de cette thèse, nous présentons et nous montrons les avantages d'un nouveau mécanisme de commutation entre les deux modes du protocole PIM-SM. Ce mécanisme utilise une coordination entre les membres concernés par la commutation. De plus, il prend en compte les contraintes réseaux et les besoins de membres.

L'Internet du futur aura a transporter les donnees de nouvelles applications avec des garanties de qualite de service (QdS). De ce besoin resulte la necessite d'en re-concevoir l'architecture. Par ailleurs, la structure de l'Internet, compose de domaines independants vis a vis de la gestion de la QdS, pose le probleme de la continuite du service lors de la traversee de plusieurs domaines. Face a ces deux problematiques, la these soutenue est celle d'un systeme de communication offrant des garanties de QdS par flux applicatif dans un environnement Internet multi domaines. Son architecture integre un plan communication comportant plusieurs services/protocoles aux niveaux Transport et IP, et un plan signalisation assurant la gestion des ressources a la frontiere des domaines. Nos contributions sont les suivantes. Nous proposons un modele de caracterisation des services IP et Transport, etaye par : (1) des mesures realisees sur une plate forme nationale, (2) une etude en simulation (ns-2) et (3) des mesures realisees sur une plate-forme emulant (Dummynet) un Internet multi domaines. Nous etendons l'architecture de communication proposee dans des travaux anterieurs de facon a abstraire le niveau applicatif de la complexite du choix des services Transport et IP, et a optimiser l'utilisation des ressources du reseau. Nous specifions en UML et implementons en Java notre proposition d'architecture de signalisation permettant d'assurer la continuite du service offert aux applications sur tous les domaines traverses. Enfin, nous testons le systeme de communication avec deux types d'applications multimedias sur une plate-forme emulant le comportement de plusieurs domaines DiffServ.