QoS-VNS-CS: QoS constraints Core Selection Algorithm based on Variable Neighborhood Search Algorithm

Within the development of network multimedia technology, more and more real-time multimedia applications arrive with the need to transmit information using multicast communication. Multicast IP routing is an important topic, covering both theoretical and practical interest in different networks layers. In network layer, there are several multicast routing protocols using multicast routing trees different in the literature. However PIM-SM and CBT protocols remains the most used multicast routing protocols; they propose using a shared Core-based Tree CBT. This kind of tree provides efficient management of multicast path in changing group memberships, scalability and performance. The prime problem concerning construction of a shared tree is to determine the best position of the core. QoS-CS’s problem (QoS constraints core Selection) consists in choosing an optimal multicast router in the network as core of the Shared multicast Tree (CBT) within specified QoS constraints associated. The choice of this specific router, called RP in PIM-SM protocol and core in CBT protocol, affects the structure of multicast routing tree, and therefore influences performances of both multicast session and routing scheme. QoS-CS is an NP complete problem need to be solved through a heuristic algorithm, in this paper, we propose a new core Selection algorithm based on Variable Neighborhood Search algorithm and new CMP fitness function. Simulation results show that good performance is achieved in multicast cost, end-to-end delay, tree construction delay and others metrics

QoS aware multicast routing protocols evaluation through simulation

In networking research, the simulation is often the single way to overcome the lack of equipment needed for laboratory setup of complex experimental topologies, with diverse traffic pattern scenarios. Even for simpler topologies and traffic scenarios, the simulation remains attractive due to the available facilities on data collection, graphics generation and step by step analysis of different protocol machines. Inter-domain multicast scenarios, where heterogeneous QoS requirements should be considered, is a particular example where both complexity and resources availability justify the use of simulation. This paper reports the experience gained by the usage of simulation tools in multicast routing with QoS. It is not focused on the real simulation results reported but on the process used to obtain them. NS-2 has been used as the base of this work

Class-based multicast routing in interdomain scenarios

DiffServ-like domains bring new challenges to quality of service (QoS) multicast routing simply by shifting the focus from individual flows into classes of flows. Packets are marked at edge routers and receive differentiated treatment according to the class and not the flow that they belong to. DiffServ therefore became adverse to multicast, as packet replication inside the domain may require classification and remarking functions not present in core nodes. At the interdomain level, no doubt multicast QoS complexity is increased by the interleaving of DiffServ and non-Diffserv domains, making it more difficult to address QoS multicast in an end-to-end perspective. In today’s real interconnection world, classes of service have no meaning in certain links of a full interdomain path. While the problem is not new, as already pointed out, there are no real efforts to bring multicast back to a class-of-service domain without compromising its model of operation. In this article, we present an innovative multicast QoS routing strategy, clearly designed for the new class-of-service paradigm. The solution is based upon the construction of multiple trees, one per class of service available, while still allowing receivers to shift for source-specific trees in its own class of service. The strategy is presented in a full end-to-end perspective. Intradomain trees use differentiated routing paths thus helping traffic differentiation. Intradomain receivers are allowed to shift from shared trees into an adequate class-of-service source tree. At interdomain level, each class-of-service interdomain tree branch is accomplished by means of an improved path probing strategy enabling for QoS path establishment. This paper presents this new strategy, and associated protocols, for constructing several multicast and directed distribution trees, one per class of service, within each multicast group. This new strategy and associated protocols are then simulated using NS-2 platform. Simulation results are analyzed and compared with other multicast routing solutions, both at intra- and interdomain levels

Avaliação de controlo de sessões multicast em redes com contexto

Mestrado em Engenharia Electrónica e TelecomunicaçõesOs utilizadores pretendem aceder, cada vez mais, a serviços multimédia com requisitos mais exigentes e personalizados. As limitações impostas pelos ambientes existentes (internet, 3G) para fornecer estes serviços levam à procura de melhores soluções, nomeadamente uma gestão eficaz das sessões multiparty. Neste tipo de soluções é normalmente utilizado o multicast, já que este permite reduzir os recursos utilizados, diminuindo o número de pacotes na rede. Contudo, o multicast não está consistente ao nível dos cenários de mobilidade, fundamentais nas redes de próxima geração. Actualmente existe uma vasta gama de tecnologias de acesso sem fios como WiFi, GPRS, UMTS e WiMAX. No futuro estas tecnologias diferentes complementar-se-ão convergindo numa infra-estrutura heterogénea capaz de fornecer um melhor serviço aos utilizadores, denominadas de redes 4G. A evolução dos terminais móveis também permitirá que estes se liguem simultaneamente a várias redes de acesso. Para uma melhor distribuição dos serviços dos utilizadores pelas redes de acesso disponíveis são necessários novos mecanismos de selecção. Uma nova selecção da rede baseada em informação de contexto (entidades e ambiente) tem tido grande relevo na comunidade científica. Assim, aplicações e rede reagem a alterações de contexto para uma melhor selecção da mesma. A dissertação apresentada encontra-se no âmbito do transporte multiparty com informação de contexto e reserva de recursos, permitindo a entrega do conteúdo de uma forma personalizada e com Qualidade de Serviço a vários utilizadores móveis, independentemente da tecnologia de acesso de cada um e da própria tecnologia da rede. Em suma, é utilizada uma arquitectura de rede baseada em informação de contexto e que reage eficazmente a alterações do mesmo. De forma a implementar a proposta apresentada recorreu-se à criação de várias entidades no simulador de redes NS-2. Os resultados foram obtidos usando diferentes cenários, avaliando a influência de cada parâmetro individualmente. Demonstrou-se que a arquitectura implementada permite suportar uma entrega dos conteúdos de uma maneira personalizada e independente da tecnologia utilizada. Obteve-se ainda uma boa gestão dos recursos da rede e uma melhoria na experiência percepcionada pelo utilizador através da selecção total da rede com base numa entidade de controlo central. A introdução do overlay de transporte multiparty melhora o comportamento geral da rede, minimizando as reconfigurações frequentes necessárias.Nowadays, more and more users want to access multimedia services with strong and personalized requirements. The limitations intrinsic to current environments (Internet and 3G) to provide this type of services motivate the research for an efficient management of multiparty sessions. The solution can also be based on multicast implementation, since it reduces resources utilization, decreasing the number of packets in the network. However, current multicast is not a strong solution in mobility scenarios, essential in next generation networks. Currently there is a wide range of wireless access technologies such as WiFi, GPRS, UMTS and WiMAX. In the future, these different technologies will converge in a complementary manner forming a heterogeneous infrastructure able to offer a better service to its users, usually named 4G. The evolution of mobile terminals will also allow them to connect simultaneously to several access networks. In order to a better distribution of the users services throughout available access networks, new selection mechanisms are required. A new network selection based on context information (entities and environments) is having a relevant role in scientific community. So, applications and networks react according to context changes, improving network selection. This Thesis is in the scope of context-aware multiparty transport with resources allocation, allowing the delivery of content in a personalized way with Quality of Service to several users, independently of the technology and the network. Resuming, the solution implements a context-aware network architecture that reacts efficiently to its changes. In order to implement this architecture, new entities were created in the network simulator NS-2. The results were obtained using different scenarios, evaluating the influence of each parameter independently. It was demonstrated that the integration of several components, allows a delivery of contents in a personalized manner and independently of the technology. The results showed a better management of the network resources and users experience, throughout the total network selection, based on a central control unit. The multiparty transport overlay improves the network behaviour, minimizing the necessary frequent reconfigurations

Sobre-reserva em redes com controlo centralizado e distribuído

Mestrado em Engenharia ElectrónicaAs redes de futura geração são esperadas vir a suportar novas funcionalidades (escalonamento, qualidade de serviço, muticast) sobre tecnologias de transporte heterogéneas, com suporte para muitos utilizadores simultaneamente e a um custo razoável. Neste sentido, esforços de investigação recentes afirmam que o uso de mecanismos de sobre-reserva em redes com classes de serviço é promissor, pois permite a optimização do desempenho global da rede, uma vez que possibilita tratar agregados de fluxos simultaneamente. No entanto, as propostas existentes enfrentam vários problemas de eficiência, onde existe desperdício de largura de banda e, portanto, o aumento desnecessário da probabilidade de bloqueio da sessão. Por outro lado, a crescente utilização da Internet, faz com que mecanismos centralizados fiquem sobrecarregados, ocorrendo cada vez mais falhas. Embora os mecanismos centralizados possam ser mais fáceis de gerir, deixam muito a desejar em comparação com sistemas distribuídos. A descentralização permite a execução simultânea de operações em entidades diferentes através de uma rede, conseguindo um melhor desempenho. No entanto, exige a sincronização de informações de controlo para evitar decisões erradas e incompatíveis. Esta dissertação implementa e testa uma plataforma que usa mecanismos de sobre-reserva de recursos dinamicamente (COR, A-COR), que permitem gerir agregados de fluxos assegurando requisitos de qualidade de serviço, tanto num cenário de controlo centralizado como distribuído, e suporte para multicast e balanceamento de carga. Particularmente, estes mecanismos levam em consideração a partilha de interfaces pelos diversos caminhos da rede, melhorando a distribuição de recursos disponíveis pelas diversas classes. Mais importante, tudo é feito de forma dinâmica e apenas quando necessário para cada interface na rede, melhorando a prestação global do serviço. Self- Organization of Multiple Edge Nodes (SOMEN) opera de uma forma distribuída permitindo que pontos chave na rede (CDP) operem em conjunto para controlar os recursos da rede mantendo um nível baixo de mensagens e processamento. Os resultados obtidos por simulação demonstram que sobre-reserva de recursos pode prevenir a violação dos requisitos de qualidade de serviço enquanto minimiza significativamente a probabilidade de bloqueio da sessão. Demonstram também que a distribuição do controlo da rede é escalável para redes futuras, mantendo baixos níveis de mensagens de sincronização.Future Networks are expected to support new features and capabilities (scalability, Quality of Service (QoS), multicast) in order to provide support for value added sessions (e.g. multimedia, personalized, haptics, etc.) over heterogeneous transport technologies to many users simultaneously, and at reasonable cost. Hence, recent research efforts claim that class-based network resource over-provisioning is promising, since it allows minimizing undesired QoS control states, processing and signaling overheads to improve system overall performance. However, existing proposals mostly waste bandwidth and therefore increase session blocking probability unnecessarily while incurring QoS violation. Besides, the increasing dependence on IT technologies is making central controllers more and more bottlenecked while the network infrastructures are subject to frequent failures. As an alternative, decentralization allows simultaneous operations at distributed entities throughout a network, achieving better performance. Nevertheless, it must be correctly designed to assure a cost-effective synchronization of the distributed decision points to prevent wrong and incompatible decisions. Keeping this in mind, this dissertation implements and provides a platform to assess new mechanisms for dynamic aggregate QoS overreservations in both centralized and decentralized architectures with support for multicasting and load balance. In particular, the mechanisms improve the control of aggregated resources by taking communication paths correlation patterns and sessions requests into account and efficiently distribute the shared surplus of reservations among existing Classes of Service (CoSs). More importantly, this is performed in a dynamic manner for every outgoing interface inside a network upon need, in a way that effectively allows system overall performance optimization. Moreover, a decentralization control approach, assuring an efficient Self-Organization of Multiple Edge Nodes (SOMEN) has also been evaluated. Hence, multiple distributed network Control Decision Points (CDPs) are enabled to cooperate and self-manage keeping low control signaling, states and processing load. The simulation results prove that efficient bandwidth over-reservation can effectively prevent QoS violation while significantly minimizing the waste of bandwidth and the unnecessary increase of session blocking probability. Further, they show a cost-effective decentralization of the control in current and future networks with low synchronization signaling loads

Proof-of-Concept Application - Annual Report Year 2

This document first gives an introduction to Application Layer Networks and subsequently presents the catallactic resource allocation model and its integration into the middleware architecture of the developed prototype. Furthermore use cases for employed service models in such scenarios are presented as general application scenarios as well as two very detailed cases: Query services and Data Mining services. This work concludes by describing the middleware implementation and evaluation as well as future work in this area. --Grid Computing

Building a test bed for simulation analysis for the internet of things

Mestrado com dupla diplomação com a Universidade Tecnológica e Federal do ParanáThe Internet of Things (IoT) enables the mix between the physical and informational world. Physical objects will be able to see, hear, think together, share information and coordinate decisions, without human interference in a variety of domains. To enable this vision of IoT in large scale is expected of the equipment to be low-cost, mobile, power efficient, computational constrained, and wireless communication enabled. This project performs an extensive overview of the state-of-the-art in communication technologies for IoT, simulation theory and tools. It also describes test bed for IoT simulation and its implementation. The simulation was built with Castalia Simulator (i.e. Wireless Sensor Networks (WSN) network) and INET framework (i.e. IP network), both extends OMNeT++ features. There are two independent networks that communicate through files and exchange information about source, destination, payload and simulation time. Analyzing the outputs is possible to assure that the routing protocol that is provided in the Castalia Simulator does not provide any advantage in terms of packets loss, packets reception or energy consumption.A Internet das Coisas (IoT) permite a mistura entre o mundo físico e informacional. Objetos físicos serão capazes de ver, ouvir, pensar juntos, compartilhar informações e coordenar decisões, sem interferência humana em uma variedade de domínios. Para permitir essa visão de IoT em larga escala, espera-se que o equipamento seja de baixo custo, móvel, eficiente em termos de energia, com restrições computacionais e possibilite a comunicação sem fio. Este projeto faz uma extensa visão geral do estado da arte em tecnologias de comunicação para IoT, teoria de simulação e ferramentas. Também descreve o banco de testes para simulação de IoT e sua implementação. A simulação foi construída com o Simulador Castalia (ou seja, rede WSN) e o framework INET (ou seja, rede IP), ambos estendem os recursos do OMNeT ++. Existem duas redes independentes que se comunicam através de arquivos e trocam informações sobre origem, destino, carga útil e tempo de simulação. Analisando os resultados é possível garantir que o protocolo de roteamento que é fornecido no Simulador Castalia não oferece qualquer vantagem em termos de quebra de pacotes, recepção de pacotes ou consumo de energia

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks