Submitted by João Arthur Martins (joao.arthur@ufpe.br) on 2015-03-11T18:40:22Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Lorena Marques.pdf: 2473408 bytes, checksum: ae5cba07c563d08350f8ddc5184cffee (MD5) / Approved for entry into archive by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-13T13:10:17Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Lorena Marques.pdf: 2473408 bytes, checksum: ae5cba07c563d08350f8ddc5184cffee (MD5) / Made available in DSpace on 2015-03-13T13:10:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Lorena Marques.pdf: 2473408 bytes, checksum: ae5cba07c563d08350f8ddc5184cffee (MD5) Previous issue date: 2013-02-25 / FACEPE / A crescente disponibilidade de acesso sem fio através de diferentes tecnologias (e.g., IEEE 802.11, IEEE 802.16 e 3G/UMTS) e o aumento do número de dispositivos com suporte a múltiplas interfaces heterogêneas possibilitam uma gama de oportunidades de conectividade sem fio aos usuários. Tradicionalmente, para este cenário, tem-se proposto algoritmos, protocolos e arquiteturas para a escolha da melhor rede de acordo com o perfil do usuário, característica da aplicação e da rede. Outra possibilidade de pesquisa, ainda não tão explorada no âmbito sem fio, é a distribuição de carga e conteúdo através de múltiplos caminhos simultâneos. Esta característica é conhecida como multihoming e pode dispor redundância de caminhos, oferecendo, dessa forma, certo grau de confiabilidade na rede. O grande desafio para implantação do multihoming em redes móveis heterogêneas decorre da instabilidade que esses ambientes possuem. O problema se agrava quando existem várias interfaces tentando se comunicar simultaneamente. O CMT (Concurrent Multipath Transfer) usa a característica multihoming do SCTP (Stream Control Transmission Protocol) para transmitir dados através de múltiplos caminhos fim-a-fim simultaneamente. No entanto, o CMT não possui um bom desempenho em redes com diferentes características, especialmente em se tratando de vídeo. Esta dissertação propõe o aCMT-UC (Adaptive CMT-User Centric), uma solução baseada em multihoming/centrada no usuário para a distribuição de carga em redes heterogêneas sem fio, tornando o CMT adaptável à dinâmica dos caminhos. O aCMT-UC prioriza os quadros de vídeo mais importantes que são transmitidos pelo melhor caminho sem fio. A distribuição de carga e priorização de vídeo são realizadas através da atribuição dinâmica de diferentes pesos para os caminhos sem fio, de acordo com um procedimento inteligente baseado em Lógica Fuzzy. Foram avaliadas métricas de Qualidade de Serviço e Experiência (QoS/QoE) em uma rede formada pelas tecnologias IEEE 802.11, IEEE 802.16 e 3G/UMTS em um simulador de redes (ns-2). Os resultados obtidos demonstram a eficácia da proposta em garantir QoS, bem como, o suporte adequado aos requisitos de tráfego de vídeo.

Orientador: Edmundo Roberto Mauro Madeira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-11T08:18:18Z (GMT). No. of bitstreams: 1 Paschoalino_RacheldeCarvalho_M.pdf: 2064052 bytes, checksum: e9b127c3cba93b04b66044600728e3a9 (MD5) Previous issue date: 2008 / Resumo: Devido à facilidade de implantação e gerência, as redes mesh sem fio constituem uma escolha natural para atender a crescente demanda por acesso sem fio com cobertura em larga escala. Formadas por roteadores mesh interligados através de enlaces sem fio, as WMNs (Wireless Mesh Networks) fornecem um backbone flexível para diversas aplicações e serviços. Entretanto, os protocolos de roteamento existentes aplicados às WMNs não provêem escalabilidade, reduzindo a vazão conforme o tamanho da rede aumenta. Esta dissertação apresenta um protocolo de roteamento escalável com QoS para WMNs multirádio. Incorporamos uma métrica local de qualidade do enlace e suporte a múltiplos rádios ao protocolo OLSR (Optimized Link State Routing). A métrica de qualidade é usada na seleção de nós especiais de relay, que irão compor as rotas. Variações na métrica de qualidade são tratadas na vizinhança de 1 salto, preservando estabilidade no roteamento. Por sua vez, o uso de múltiplos rádios por nó provê um melhor aproveitamento do espectro sem fio, minimizando a contenção. Essa abordagem simples e escalável permite distribuir o tráfego na rede por caminhos com enlaces de melhor qualidade. Através das simulações realizadas, demonstramos que o protocolo proposto, chamado LQ-OLSR (Link Quality OLSR), traz melhorias expressivas na vazão, atraso e perda de pacotes em relação ao OLSR original, com um aumento mínimo do overhead / Abstract: Due to their deployment and management simplicity, Wireless Mesh Networks (WMNs) have become a natural way to fulfill the increasing demand for large area wireless coverage. Formed by mesh routers connected by wireless links, WMNs provide a flexible backbone for various applications and services. Nevertheless, the available routing protocols applied to WMNs suffer from scalability, where throughput decreases as the number of nodes grows. In this thesis, a scalable QoS routing protocol for multi-radio WMNs is proposed. We incorporate a locallink quality metric and multi-radio support in the OLSR (Optimized Link State Routing) protocol. The quality metric is used in the selection of relay nodes which will form the routes. Significant changes to link quality metric are treated in l-hop neighborhood, preserving route stability. Using multiple radios in each node allows a better utilization of the wireless spectrum, minimizing contention. This simple and scalable approach permits traffic distribution among better quality links. Simulations were conducted and the results showed expressive performance improvements .concerning throughput, delay and packet loss of the proposed protocol LQ-OLSR (Link Quality OLSR) over the original OLSR, with a minimum overhead increase / Mestrado / Redes de Computadores / Mestre em Ciência da Computação

The evolution of 3G systems has contributed to a significant amount of progress towards 4th generation wireless technology, Long Term Evolution (LTE). On the other hand, demand for more bandwidth has been evidenced by the ever growing usage of real-time application such as video conference. For instance, users tend to have reliable and efficient connection when they are on the go maintaining the minimum quality of the video conference. In order to meet these challenges, QoS of LTE makes it an ideal solution. A simplified IP-based system architecture and introduction of Orthogonal Frequency Division Multiplexing (OFDM) have made LTE possible to satisfy its promise targets. In addition, LTE capabilities are further improved with enhanced Quality of Service (QoS) support for multiple data services, such as voice and other multimedia applications. LTE packet scheduling plays an essential role as part of LTE's Radio Resource Management (RRM) to enhance the system's data rate and to support the diverse QoS requirements of mobile services. LTE packet scheduler should intelligently allocate radio resources to mobile User Equipment’s (UEs) such that the LTE network adheres to its performance requirements. In our thesis work, we conduct a comprehensive performance evaluation of LTE scheduling algorithms for real-time application such as video conferencing traffic. The evaluation is carried out using the OPNET simulator. In order to analyze the performance LTE scheduling algorithm, our analysis involved with LTE Admission Control is two fold. First, 6 scenarios have been modeled in way that 3 of 6 scenarios deals with no LTE admission control techniques applied in the proposed network models while other 3 scenarios deals with LTE scheduling techniques applied. Secondly, video conferencing sessions are configured between two LTE cells with same number of UEs in which all UEs under each cell in the entire proposed network modeling scenarios. In order to make our evaluation more realistic we have applied various network loads so that we can observe how LTE scheduling techniques work its best in the case of highly loaded network. Our simulation results show that video conferencing node with the highest priority maintains tolerable delay and loss while nodes without scheduling techniques experience worst performance.

Over the last years, we have witnessed a rapid deployment of real-time applications on the Internet as well as many research works about Quality of Service (QoS) in particularly IPv4 (Internet Protocol version 4). The inevitable exhaustion of the remaining IPv4 address pool has become progressively evident. As the evolution of Internet Protocol (IP) continues, the deployment of IPv6 QoS is underway. Today, there is limited experience in the deployment of QoS for IPv6 traffic in MPLS backbone networks in conjunction with DiffServ (Differentiated Services) support. DiffServ itself does not have the ability to control the traffic which has been taken for end-to-end path while a number of links of the path are congested. In contrast, MPLS Traffic Engineering (TE) is accomplished to control the traffic and can set up end-to-end routing path before data has been forwarded. From the evolution of IPv4 QoS solutions, we know that the integration of DiffServ and MPLS TE satisfies the guaranteed QoS requirement for real-time applications. This thesis presents a QoS performance study of real-time applications such as voice and video conferencing over DiffServ with or without MPLS TE in IPv4/IPv6 networks using Optimized Network Engineering Tool (OPNET). This thesis also studies the interaction of Expedited Forwarding (EF), Assured Forwarding (AF) traffic aggregation, link congestion, as well as the effect of various performance metrics such as packet end-to-end delay, packet delay variation, queuing delay, throughput and packet loss. The effectiveness of DiffServ and MPLS TE integration in IPv4/IPv6 network is illustrated and analyzed. The thesis shows that IPv6 experiences more delay and loss performance than their IPv4 counterparts. / Author (1): Md. Tariq Aziz Address: C/O: Murshed Gularm, Nykarleby Gatan 134, 16474 Kista, Stockholm, Sweden Author (2): Mohammad Saiful Islam Address: Minnervavägen 22B, 371 43 Karlskrona, Sweden

Mobile Ad-hoc network (MANET) is a collection of mobile nodes which communicate over wireless channels without any centralized control or existing infrastructure. The freely movement of nodes allow them to join or leave the network independently. Due to node mobility, wireless channels and limited resources makes the provision of Quality of Services (QoS) in MANETs very challenging. With the emerging use of multimedia applications over MANETs which requires different types of QoS provision from the networks. The Admission Control (AC) and QoS-Aware routing (QAR) protocols have made a progress in provision of QoS up to some extents. In this thesis, various AC and QAR protocols are reviewed and their characteristics and limitations are identified. We also make a comparison between DSR and AODV routing protocols in different network scenarios. / The literature study shows that the performance of network layer best-effort protocols has been improved with the use of QAR and AC protocols to sustain the QoS requirements of the applications. In current literature AC and QAR protocols are satisfying single metric of QoS. At the same time different applications such as multimedia applications which require various types of assurance from the network on the Quality of services (QoS) The simulation results show that DSR performance is better than AODV when we have less traffic load.

Le besoin des applications de streaming multimédia en temps réel sur Internet ne cesse d’accroître. Dans ce contexte, les réseaux Pair-à-Pair (P2P) jouent un rôle prépondérant afin d’assurer une transmission robuste et extensible (scalable) de contenu multimédia à grand-échelle. Cependant, le déploiement des applications de streaming multimédia à travers les réseaux P2P présente plusieurs verrous. En effet, les applications de streaming vidéo nécessitent une garantie de performances temps réel en termes de : délai minimal de bout-en-bout, faible taux de perte de paquets et garantie de la bande passante. Par ailleurs, un réseau P2P est composé d’un ensemble de terminaux interconnectés à travers des réseaux hétérogènes, n’ayant pas forcément les mêmes caractéristiques requises afin d’offrir la même qualité vidéo aux clients finaux.Dans cette thèse, nous analysons différents problèmes liés au streaming en-direct (Live) ou à la demande (VoD) de la vidéo sur les réseaux P2P, et nous proposons un ensemble de mécanismes pour y remédier. / There is an increasing demand for efficient deployment of real-time multimedia streaming applications over Internet. In this context, Peer-to-Peer (P2P) networks are playing an important role for supporting robust and scalable transmission of multimedia content to large-scale and massive receivers. P2P networks consist of different heterogeneous networks and devices, which may not have symmetric characteristics to offer the same video quality to end clients. The deployment of streaming applications such as live and on-demand over P2P networks is challenging. Indeed, video streaming applications require real-time performance guarantee in terms of low end-to-end delay, low packet loss and guaranteed available bandwidth. Moreover, P2P video streaming also experiences the problems of long start-time and churn-induced instability. The situation leads to affect the viewing experience of the users in P2P networks.The aim of this thesis is to analyze these issues and to propose quality-aware mechanisms for both live and on-demand streaming over P2P networks. Our contributions in this dissertation are threefold. First, we propose a small world overlay organization mechanism allowing efficient organization of peers to reduce the end-to-end delay for live streaming applications. Second, we propose a mechanism for cooperative prefetching with differentiated chunks scheduling suitable for P2P video-on-demand (VoD) to efficiently handle seek operations while reducing the response latency and increasing the hit ratio. Finally, we present a smoothing mechanism for layered streaming in P2P networks. The mechanism aims to reduce the number of layer changes under varying network conditions while at the same time achieving a high delivery ratio.

Nowadays Wireless LAN is playing a more and more important role in network systems. After 1999, in which the IEEE organization published its Wireless Local Network standard 802.11[1], many people saw the advantages of the standard but also the lack of support for multimedia streaming. A lot of research work has been done on the proposed IEEE 802.11e standard draft during the past 4 years. It is supposed to be able to fully support Quality of Service. The final version will be published early in 2004. In my thesis, I propose two possible methods to improve the performance of service differentiation in the MAC layer. The first one is calledPCWA (Practical Contention Window Adjustment). It is a method with which the station finds a best size of its contention window when running the EDCF (Enhanced Distributed Coordination Function) access method. It helps to improve the total system throughput, the jitter and the delay of traffics with different priorities. The second method is called AIPM (Adaptive Initiative Polling Machine). It uses the polling mechanism for differential service, intelligently arranging the polling time to reduce the delay as much as possible, achieving large improvement in performance. This method significantly increases the total system throughput, while the delay and jitter of the traffics are very much small in comparison to EDCF.

ABSTRACT Ad hoc network is a collection of wireless mobile nodes which dynamically form a temporary network without the use of any pre-existing network infrastructure or centralized administration. They operate by interactions among their neighbourhood wireless mobile nodes. Such interactions provide the required administration and control functions that support networks of that nature. Ad hoc wireless networks provide significant advantages on wide environments and certain applications. These types of networks could be internally fault-resilient, since they do not work under fixed topology. However, the networks are time-varying since all the nodes operate as mobile. Ad hoc networks automatically adapt to environments which are at the extremes of high mobility with low bandwidth and vice versa. In an ad hoc network that is multi-hop and for two nodes that are not direct neighbours, the communication between these nodes require that there should be a relay of message by the node that is in between them. Each of these nodes in the network acts as a router and also as a communication end-point. The cooperation and collaboration of all network layers is required for the provision of QoS support. Growth in wireless communication has been very astronomical in the past few years. Every technology is going wireless. Quality of service is a big issue that has to be addressed. Our main concern here is QoS routing. Every node broadcasts beacon packets periodically identifying it and its QoS characteristics. In the centre of ad hoc networking lies beaconing mechanism because without this, a node will not know its adjacent neighbours that changes dynamically in an ad hoc networking scenario. For routing, the knowledge of adjacent neighbours is very essential. To support QoS for real time traffic we need to know not only the minimum delay path to destination, but also the bandwidth available on it. We would also deal with how to improve QoS in an ad hoc wireless network; and Universal Mobile Telecommunications Systems (UMTS). QoS in an ad hoc wireless network pose a complex issue because of dynamic nature of the network topology; but, it would be addressed here.

Multi-Protocol Label Switching (MPLS) emerged as a suitable solution to optimization of Internet Protocol (IP) networks. It improves network efficiency, utilization of resources and resilience in packet switched networks. With MPLS, packet forwarding decisions are made based on label inspection rather than packet header information. While MPLS is native to packet switched networks, Generalized Multiprotocol Label Switching (GMPLS) extends MPLS functionality to networks that support non-packet switched domains such as time, lambda and fiber. GMPLS also offers better resource management through the use of a new protocol; Link Management Protocol (LMP). In this work, a performance evaluation of GMPLS and MPLS control plane signaling protocols was performed. Further, a control plane interworking model for MPLS and GMPLS networks was proposed. Simulations were carried out to examine the performance of signaling protocols in an MPLS network configured with, and without Quality-of-Service (QoS). Conclusions on the performance characteristics of each signaling protocol were made based on the collected results.

Jönköping Energi AB (JEAB) is a local energy supplier for the county of Jönköping. JEAB also maintain the local Metropolitan Area Network (MAN). They have recently installed GPON in a portion of their network and have connected it to the MAN via an Extreme switch. However JEAB would prefer to use Cisco equipment instead of Extreme since the MAN comprises of Cisco hardware. They require a solution to connect GPON to the MAN with a recently purchased line card (Cisco 7600 ES20) which can be installed in a Cisco 6500 Catalyst switch. There is also a possible solution with an Alcatel-Lucent 7450 ESS-1 switch. The proposed solution is to use Virtual Private LAN Service (VPLS), though the exact implementation required is unknown. Additionally JEAB have asked for research into GPON and VPLS in order to improve their understanding of both techniques. This would be of benefit to them both now and in the future. In order to achieve the stated objectives the following questions are raised: • How does GPON work? • How does VPLS work? • How can GPON be connected to the MAN via Cisco Systems 6500 Catalyst switch/7600 Router? • How can GPON be connected to the MAN via Alcatel-Lucents 7450 ESS-1? The research into GPON and VPLS provides the required background knowledge in order to investigate how GPON can be connected to the MAN. The main body of the work is to analyse the requirements of the company and build a configuration which satisfies them. The desired implementation via Cisco Systems solution was deemed unsuitable due to a feature of DHCP option 82 which did not function as required. The focus then turned to Alcatel-Lucents solution. The resulting solution uses a part of VPLS via Alcatel-Lucents 7450 ESS-1. All the key elements are included, including hiding customer VLANs from the ISP and per-service QoS bandwidth management. The conclusion is that whilst using Alcatel-Lucents solution means a deviation from the all-Cisco implementation that had been planned; the benefit of including all the desired functionality outweighs the mixing of manufacturers. The techniques of GPON and VPLS are extremely versatile and can be used in a variety of networks. Therefore there is scope for further research into how these two techniques can be used together in other types of MAN.