The all-over trend for an universal access and ubiquitous access to the Internet is driving a revolution in our societies. In order to support this era of nomadic applications, new flexible network architectures have emerged. They are referred to as “wireless ad-hoc networks.” <p><p>Since human-operated devices will more likely be used indoor, it leads to many issues related to the strength of the fading in this environment. Recently, it has been suggested that a possible interaction might exist between various parameters of the ad-hoc networks and, more precisely, between the propagation model and the routing protocol. <p><p>To address this question, we present in this dissertation a cross-layer perspective of the analysis of these indoor ad-hoc networks. Our reasoning is made of four stages. First, the cross-layer interactions are analyzed by the means of multivariate statistical techniques. Since a cross-layering between the physical layer and the routing protocol has been proven to be significant, we further investigate the possible development a physical layer-constrained routing algorithm. <p><p>Second, fundamental equations governing the wireless telecommunications systems are developed in order to provide insightful informations on how a reliable routing strategy should be implemented in a strongly-faded environment. After that, and in order to allow a better spatial reuse, the routing protocol we propose is further enhanced by the adjonction of a power control algorithm. This last feature is extensively analyzed and a closed-form expression of the link probability of outage in presence of non-homogeneous transmission powers is given. Numerous simulations corroborate the applicability and the performance of the derived protocol. Also, we evaluate the gain, in terms of radio channel ressources, that has been achieved by the means of the power control algorithm. <p><p>Third, an architecture for the interconnection with a cellular network is investigated. A closed-form expression of the relaying stability of a node is given. This equation expresses the minimal requirement that a relaying node from the ad-hoc network must fullfil in order to bridge properly the connections to the base-station. <p><p>Finally, a real-life implementation is provided as a validation of the applicability of this novel ad-hoc routing protocol. It is concluded that, both from the performance and the spatial re-use point-of-views, it can be taken advantage from the cross-layering between the physical and the routing layers to positively enhance the networking architectures deployed in an indoor environment. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

Multihoming allows nodes to be multiply connected to the network. It forms the basis of features which can improve network responsiveness and robustness; e.g. load balancing and fail-over, which can be considered as a choice between network locations. However, IP today assumes that IP addresses specify both network location and node identity. Therefore, these features must be implemented at routers. This dissertation considers an alternative based on the multihoming approach of the Identifier Locator Network Protocol (ILNP). ILNP is one of many proposals for a split between network location and node identity. However, unlike other proposals, ILNP removes the use of IP addresses as they are used today. To date, ILNP has not been implemented within an operating system stack. I produce the first implementation of ILNP in FreeBSD, based on a superset of IPv6 – ILNPv6 – and demonstrate a key feature of ILNP: multihoming as a first class function of the operating system, rather than being implemented as a routing function as it is today. To evaluate the multihoming capability, I demonstrate one important application of multihoming – load distribution – at three levels of network hierarchy including individual hosts, a singleton Site Border Router (SBR), and a novel, dynamically instantiated, distributed SBR (dSBR). For each level, I present empirical results from a hardware testbed; metrics include latency, throughput, loss and reordering. I compare performance with unmodified IPv6 and NPTv6. Finally, I evaluate the feasibility of dSBR-ILNPv6 as an alternative to existing multihoming approaches, based on measurements of the dSBR's responsiveness to changes in site connectivity. We find that multihoming can be implemented by individual hosts and/or SBRs, without requiring additional routing state as is the case today, and without any significant additional load or overhead compared to unicast IPv6.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-11-01T15:35:45Z No. of bitstreams: 1 Clebio Dossa_.pdf: 1252617 bytes, checksum: 784b95c29ee09e2a922686b26cb7aa51 (MD5) / Made available in DSpace on 2016-11-01T15:35:45Z (GMT). No. of bitstreams: 1 Clebio Dossa_.pdf: 1252617 bytes, checksum: 784b95c29ee09e2a922686b26cb7aa51 (MD5) Previous issue date: 2016-08-18 / Nenhuma / Atualmente, muitos serviços distribuem a carga entre diversos nós computacionais direcionando as conexões com alguma estratégia de balanceamento para divisão da carga. O advento do uso de redes definidas por software (SDN) está mudando paradigmas da administração de redes, absorvendo serviços especializados, automatizando processos e gerando inteligência para regras estáticas com uma grande variedade de opções de implementação. O balanceamento de carga é um dos serviços especializados que pode usufruir dos conceitos de SDN, sem definições e processos estáticos como ocorre muitas vezes nos atuais modelos usados de balanceamento de carga. A definição dos protocolos que suportam SDN usualmente permitem soluções alternativas e eficientes para este problema, desta forma, neste trabalho, é apresentada uma proposta de metodologia para balanceamento de carga entre distintos servidores de um pool com a troca do destino de tráfego realizada pela rede. Esta solução é chamada Core-based load balance (CoreLB), pois o serviço especializado de balanceamento de carga é realizado pela rede onde a administração de pacotes é nativamente realizada. A metodologia faz uso do protocolo SNMP para análise de recursos dos servidores com o objetivo de avaliar a situação de carga de cada nó computacional e de estatísticas de consumo de rede através do protocolo OpenFlow. Este trabalho avaliou o balanceamento de carga em serviços Web e a união de estatísticas de rede e da carga dos servidores, para a tomada de decisão de balanceamento, mostra-se uma metodologia eficiente e com melhores tempos de resposta ao usuário comparado com outras metodologias de avaliadas. Também melhorou a distribuição de consumo de recursos entre os servidores. / Currently, most services balance the load between distinct hosts forwarding connections with a load balance strategy in front. Usually, a dedicated appliance is responsible to performthe balance and may be a fault point and become expensive. The new concepts of computer network architecture with Software-Defined Networking (SND) are changing the network management, absorving specialist services, automating process and building intelligence to statics rules with loads of delivery options. The load balance is a specialized service that can enjoy in a positive way of SDN concepts, with low costs, in a flexible way as per the process needs instead of a plastered process definitions that occurs in many actual models. The OpenFlow protocol definition allow us to use a new solution to address this issue. This work shows a load balance purpose between distinct hosts with the destination change of connections made by the network core. It calls Core-based load balance (CoreLB) because the specialized load balance service move to the network core where the package forwarding is naturally made. This solution intend to use the SNMP protocol to analyse the hosts resources to evaluate server’s load. Using the network forwarding statistics and OS load informations, an efficient solution of load balance, the metodology proved to be efficient with better users’ response times average of 19% than no balanced scenario as well as around 9% better than others load balance strategies and a properly balance consumption of resources from hosts side. This process can be inhered in distinct models, however, this research intend to evaluate Web Services.