Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

Architecture for satellite services over cryptographically heterogeneous networks with application into smart grid

The rapid growth in the demand for Future Internet services with many emerging group applications has driven the development of satellite, which is the preferred delivery mechanism due to its wide area coverage, multicasting capability and speed to deliver affordable future services. Nevertheless, security has been one of the obstacles for both satellite services as well as smart grid group applications, especially with logical/geographical/cryptographic domains spanning heterogeneous networks and regions. In this paper, adaptive security architecture is implemented to protect satellite services for smart grid group applications. The focus is on key management and policy provisioning. Leveraging Group Domain of Interpretation (GDOI) as the standard for smart grid centralized key/policy management architecture, a single Domain of Interpretation (DOI) is deployed and evaluated critically in terms of the added protocol signaling overhead on the satellite system for a fixed-network scenario. This also partially realizes the growing trend towards the use of TCP/IP technology for smart grid applications

Using the PALS Architecture to Verify a Distributed Topology Control Protocol for Wireless Multi-Hop Networks in the Presence of Node Failures

The PALS architecture reduces distributed, real-time asynchronous system design to the design of a synchronous system under reasonable requirements. Assuming logical synchrony leads to fewer system behaviors and provides a conceptually simpler paradigm for engineering purposes. One of the current limitations of the framework is that from a set of independent "synchronous machines", one must compose the entire synchronous system by hand, which is tedious and error-prone. We use Maude's meta-level to automatically generate a synchronous composition from user-provided component machines and a description of how the machines communicate with each other. We then use the new capabilities to verify the correctness of a distributed topology control protocol for wireless networks in the presence of nodes that may fail.Comment: In Proceedings RTRTS 2010, arXiv:1009.398

Development and experimentation towards a multicast-enabled Internet

In this paper, we report our development experience and experimentation studies of two multicast routing schemes for the Internet, namely, PIM-SSM and GCMR. We detail their implementation over the Quagga open source routing suite, as well as their experimentation tests over a large-scale topology that reproduces the Internet characteristics

Mobilidade de emissores e receptores em redes com suporte de multicast

Mestrado em Engenharia Electrónica e TelecomunicaçõesEste trabalho de investigação pretende apresentar, desenvolver e avaliar uma nova solução para a mobilidade de terminais em redes IP com suporte Multicast. Tendo em conta que são cada vez mais frequentes aplicações multimédia, tais como, vídeo-conferências, IPTV, entre muitas outras, as quais requerem uma elevada largura de banda e penalizam a eficácia da rede, é necessário desenvolver trabalho nesta temática a qual se encontra ainda, nos nossos dias, pouco aprofundada. O IP Multicast consiste no envio de apenas um pacote de dados mesmo que essa informação seja pedida por vários receptores da rede. Para isso, baseiase no conceito de grupo. Os elementos da rede, que fazem parte da chamada árvore de distribuição desse grupo multicast, replicam o pacote de forma a enviar uma cópia do mesmo sempre que o caminho para os receptores divergir. Com o advento da tecnologia e tendo em conta as redes de próxima geração, verifica-se que estas são essencialmente baseadas no conceito de mobilidade. Por mobilidade entende-se a capacidade de um terminal se conectar a um outro elemento (Access Router) da rede. A solução apresentada pretende oferecer de forma eficiente e transparente suporte ao movimento dos terminais minimizando os tempos de disrupção associados. Efectuou-se uma análise às soluções existentes e tendo em conta a convergência das mesmas, para resolver problemas relacionados com mobilidade de terminais multicast, uma nova solução centrada em Agentbased é apresentada. A proposta apresentada foi testada recorrendo ao simulador NS2, demonstrando a eficiência e escalabilidade desta solução de mobilidade em redes multicast. ABSTRACT: This research work aims to produce, develop and evaluate a new solution to the mobility of terminals in IP Multicast networks. Since, multimedia applications, such as, video-conferences, IPTV, and many others, are, nowadays, more common and because these applications require a lot of bandwidth and reduce the network efficiency, it is necessary to work on this subject which is not, yet, very developed. IP Multicast allows sending only one data packet even if such information is requested by several receivers on the network. For that, it is based on the concept of group. The elements on the network, which are part of the multicast delivery tree for that group, replicate the packet, when the path to receivers differ, in order to send one copy for each one. With the advent of technology and taking into account next generation networks, we see that they are essentially based on the concept of mobility. The concept of mobility means the ability of a terminal to connect to another element (Access Router) on the network. The presented solution aims to efficiently and transparently support terminals movement minimizing the correspondent disruption time. Analyzing current solutions and taking into account their convergence, in order to solve multicast terminals mobility issues, a new Agent-based solution is presented. The proposal was tested using the simulator NS2, demonstrating the efficiency and scalability of this mobility solution in multicast networks

Estudio de los mensajes de control del protocolo multicast PIM SM

OPNET es una herramienta de simulación de redes muy potente, donde se puede configurar cualquier tipo de red existente. Esta herramienta nos ayuda a "probar" sin tener que montar ninguna red física, una gran ventaja sobre todo para protocolos experimentales o para el diseño de los mismos. En este proyecto se utiliza el OPNET para explotar el protocolo multicast PIM-SM. Se establecerá un modelo de red, donde estarán configurados los nodos de forma estratégica para intentar extraer el máximo de información del comportamiento en esta situación del protocolo PIM-SM.OPNET és una eina de simulació de xarxes molt potent, on es pot configurar qualsevol tipus de xarxa existent. Aquesta eina ens ajudarà a "provar" sense haver de muntar cap xarxa física, un gran avantatge sobretot per protocols experimentals o pel disseny d'aquests. En aquest projecte s'utilitza l'OPNET per explotar el protocol multicast PIM-SM. S'establirà un model de xarxa, on estaran configurats els nodes de forma estratègica per intentar extreure el màxim d'informació del comportament en aquesta situació del protocol PIM-SM

Security and Privacy in Dynamic Spectrum Access: Challenges and Solutions

abstract: Dynamic spectrum access (DSA) has great potential to address worldwide spectrum shortage by enhancing spectrum efficiency. It allows unlicensed secondary users to access the under-utilized spectrum when the primary users are not transmitting. On the other hand, the open wireless medium subjects DSA systems to various security and privacy issues, which might hinder the practical deployment. This dissertation consists of two parts to discuss the potential challenges and solutions. The first part consists of three chapters, with a focus on secondary-user authentication. Chapter One gives an overview of the challenges and existing solutions in spectrum-misuse detection. Chapter Two presents SpecGuard, the first crowdsourced spectrum-misuse detection framework for DSA systems. In SpecGuard, three novel schemes are proposed for embedding and detecting a spectrum permit at the physical layer. Chapter Three proposes SafeDSA, a novel PHY-based scheme utilizing temporal features for authenticating secondary users. In SafeDSA, the secondary user embeds his spectrum authorization into the cyclic prefix of each physical-layer symbol, which can be detected and authenticated by a verifier. The second part also consists of three chapters, with a focus on crowdsourced spectrum sensing (CSS) with privacy consideration. CSS allows a spectrum sensing provider (SSP) to outsource the spectrum sensing to distributed mobile users. Without strong incentives and location-privacy protection in place, however, mobile users are reluctant to act as crowdsourcing workers for spectrum-sensing tasks. Chapter Four gives an overview of the challenges and existing solutions. Chapter Five presents PriCSS, where the SSP selects participants based on the exponential mechanism such that the participants' sensing cost, associated with their locations, are privacy-preserved. Chapter Six further proposes DPSense, a framework that allows the honest-but-curious SSP to select mobile users for executing spatiotemporal spectrum-sensing tasks without violating the location privacy of mobile users. By collecting perturbed location traces with differential privacy guarantee from participants, the SSP assigns spectrum-sensing tasks to participants with the consideration of both spatial and temporal factors. Through theoretical analysis and simulations, the efficacy and effectiveness of the proposed schemes are validated.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Hybrid Multicasting Using Automatic Multicast Tunnels (AMT)

Native Multicast plays an important role in distributing and managing delivery of some of the most popular Internet applications, such as IPTV and media delivery. However, due to patchy support and the existence of multiple approaches for Native Multicast, the support for Native Multicast is fragmented into isolated areas termed Multicast Islands. This renders Native Multicast unfit to be used as an Internet wide application. Instead, Application Layer Multicast, which does not have such network requirements but is more expensive in terms of bandwidth and overhead, can be used to connect the native multicast islands. This thesis proposes Opportunistic Native Multicast (ONM) which employs Application LayerMulticast (ALM), on top of a DHT-based P2P overlay network, and AutomaticMulticast Tunnelling (AMT) to connect these islands. ALM will be used for discovery and initiating the AMT tunnels. The tunnels will encapsulate the traffic going between islands' Primary Nodes (PNs). AMT was used for its added benefits such as security and being better at traffic shaping and Quality Of Service (QoS). While different approaches for connecting multicast islands exists, the system proposed in the thesis was designed with the following characteristics in mind: scalability, availability, interoperability, self-adaptation and efficiency. Importantly, by utilising AMT tunnels, this approach has unique properties that improve network security and management

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