Navegando por Assunto "Recursos de redes de computadores"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Análise de heurísticas de implantação de hetnets densas
(Universidade Federal do Pará, 2017-02-24) ARAÚJO, Welton Vasconcelos; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734
The growth of traffic in mobile networks demands a search for new technologies that can bring evolutions to the sector in question. Technologies such as heterogeneous networks (HetNets) and C-RAN (Centralized Radio Access Networks) appear as prominent solutions to this demand. However, without proper planning in the deployment of these networks, problems such as deployment cost, interference, energy efficiency and subsequent network management can lead to project unfeasibility. In this sense, this work investigates how to plan a heterogeneous network, through several heuristics in the implementation of HetNets, which will be explained later. These algorithms are evaluated in scenarios that illustrate real environments, in addition to analyzing several metrics to perform the appropriate performance evaluation of each approach. The planning of the use of centralized networks is also addressed, with a comparison with the Distributed Radio Access Network (D-RAN) model in order to show in which situations one is less costly than other. With the results, it is possible to perceive that the change in the size of the network (numbers of connected users) directly influences the results, as well as having a good indication of which technology to use in a given situation.
Acesso aberto (Open Access)
Exploring service relocation and differentiation to improve survivability on operation of resilient optical cloud networks
(Universidade Federal do Pará, 2016-03-17) SILVA, Carlos Natalino da; FRANCÊS, Carlos Renato Lisboa; http://lattes.cnpq.br/7458287841862567
Optical clouds are the combination of optical transport networks and cloud computing, which allows the integrated management of both infrastructures in one controller element. In this paradigm, cloud services can be provisioned in an anycast fashion, i.e., only the source node asking for a service and the amount of IT resources are specified, while it is up to the cloud control/management system to select the most suitable destination datacenter (DC) node. During the cloud service provisioning process resiliency is crucial in order to guarantee continuous network operations also in the presence of failures. On one hand, a survivability strategy needs to be able to meet the availability requirements of each specific cloud service, while on the other hand it must be efficient in using backup resources. Service relocation (i.e., the ability to live re-allocate one provisioned service to another DC) is one of the new features that can be used in this new paradigm, but needs to be applied carefully given its associated overhead may overload the network and DCs. Current works in the literature consider a single service model that lack representation of the heterogeneity expected for cloud services. In this context, some disrupted connection properties can be considered to improve the network survivability during the restoration process, e.g., priorities and service remaining holding time. This thesis proposes a restoration-based survivability strategy, which combines the benefits of both cloud service relocation and service differentiation concepts. The former is used to enhance the restorability performance (i.e., the percentage of successfully restored cloud services) offered by restoration, while the latter ensures that critical services are given the proper consideration while backup resources are assigned. An ILP and a heuristic are presented in order to solve the proposed survivability strategy. The proposed strategies are evaluated considering a variety of different simulation scenarios. Results show that performance achieved by the proposed ILP and heuristic are close to the ones achieved when using protection strategies, but with the inherent benefits in terms of efficient use of resources offered by restoration-based approaches.
Acesso aberto (Open Access)
Extensão do plano de controle sem fio para ambientes experimentais outdoor
(Universidade Federal do Pará, 2017-12-14) NÚÑEZ, Alexsander; ABELÉM, Antônio Jorge Gomes; http://lattes.cnpq.br/5376253015721742
The use of experimental wireless environments is a powerful tool for validating surveys in Future Internet, testing products and services. USA, Europe, Japan, Brazil, among other countries, through initiatives such as FIRE, GENI, WISHFULL and FIBRE, already provide such environments for researchers. However, the topology of these environments, in the wireless and outdoor context, is still very limited due to the need for wired infrastructure to control the devices. In this way, this dissertation presents a wireless control plan proposal for these outdoor experimental environments, maintaining its characteristics of use and adding functionalities through the proposed control architecture based on the framework called Orchestrator for Wireless Experimental Networks of Multiple Jumps Defined by Software (OREx).