265 research outputs found
On the Potential of Flow-Based Routing in Multihomed Environments
The data rates provisioned by broadband Internet access connections continue to fall short of the requirements posed by emerging applications. Yet the potential of statistical multiplexing of the last mile broadband connections remains unexploited even as the average utilization of these connections remains low. Despite recent work in this area [15, 20], two key questions remain unanswered: a) What is the attainable benefit of broadband access sharing? and b) How much of this benefit is realizable given real-world constraints? In this work we quantify the attainable benefit of a multihomed broadband access environment by proposing and evaluating several flow-based access sharing policies using a custom flow-based simulator. We then analyze how much of the performance benefit is lost due to real-world constraints by migrating from simulations to a test-lab environment employing a wireless network. Our results show that in today’s broadband Internet access scenarios, a significant reduction in download times by up to a factor of 3 is achievable
QoE de streaming de vídeo em redes veiculares com multihoming
With the ever-increasing interest and availability of vehicular networks, it is important
to study the Quality-of-Experience provided by these networks, which
ultimately determines the general public perception and thus the overall user
adoption. The broad Internet access, the evolution of user equipment, such
as smartphones, tablets and personal computers, and the appearance of services
like Youtube and Netflix, is leading the user content consumption to be
more and more in the form of video streaming. Either motivated by safety or
commercial applications, video streaming in such highly mobile environments
offers multiple challenges.
This dissertation evaluates the QoE of a multihoming communication strategy,
supported simultaneously byWAVE and Wi-Fi, for increasing the reliability and
performance of video streams in these environments. Furthermore, it also investigates
how distinct network functionalities, such as multihoming load balance,
buffering, and network metrics such as throughput and latency affect the
overall QoE observed. The results obtained led to the proposal of a multihoming
load balance policy for video applications based on access technologies,
aiming to improve QoE. The overall results show that QoE improves by 7.5%
using the proposed approach.Com o aumento contínuo do interesse e disponibilidade de redes veiculares,
é importante agora estudar a Qualidade de Experiência fornecida por estas
redes, que fundamentalmente determina a opinião e a percepção do público
geral sobre um dado serviço. O vasto acesso à Internet, a evolução dos equipamentos,
como os telemóveis atuais, tablets e computadores pessoais, e o
aparecimento de serviços como o YouTube e o Netflix, está a fazer com que
o conteúdo mais consumido seja cada vez mais em forma de streaming de
vídeo. Quer seja motivado por aplicações de segurança ou comerciais, o streaming
de vídeo em ambientes altamente móveis levanta vários desafios.
Esta dissertação avalia a Qualidade de Experiência de técnicas de multihoming,
permitindo o uso de diferentes tecnologias de comunicação, como o
WAVE e o Wi-Fi, para aumentar a fiabilidade e desempenho de streams de
vídeo nestes ambientes. Para além disso, investiga também como é que diferentes
mecanismos de rede, como o balanceamento, multihoming e o buffering,
e métricas como a taxa de transferência e latência, afetam a QoE observada.
Os resultados obtidos levaram à proposta de uma política de divisão
de tráfego para aplicações de vídeo baseada em tecnologias de acesso
para situações de multihoming, visando uma melhoria da QoE do utilizador.
Utilizando o método proposto, os resultados mostram que a experiência do
utilizador tem uma melhoria de 7,5%.Mestrado em Engenharia de Computadores e Telemátic
MobiSplit: a Scalable Approach to Emerging Mobility Networks
First ACM/IEEE International Workshop on Mobility in the Evolving Internet Architecture. Session: Architectural issues. San Francisco, California, Dec. 01 2006This paper presents a novel architecture,
MobiSplit, to manage mobility in future IP based networks.
The proposed architecture separates mobility management in
two levels, local and global, that are managed in completely
independent ways. The paper describes the flexibility
advantages that this architecture brings to operators, and how
it is appropriate for the current trend to multiple and very
different access providers and operators. Heterogeneity,
support for seamless handovers and multihoming, and
scalability issues are analyzed in the paper
Future Trends and Challenges for Mobile and Convergent Networks
Some traffic characteristics like real-time, location-based, and
community-inspired, as well as the exponential increase on the data traffic in
mobile networks, are challenging the academia and standardization communities
to manage these networks in completely novel and intelligent ways, otherwise,
current network infrastructures can not offer a connection service with an
acceptable quality for both emergent traffic demand and application requisites.
In this way, a very relevant research problem that needs to be addressed is how
a heterogeneous wireless access infrastructure should be controlled to offer a
network access with a proper level of quality for diverse flows ending at
multi-mode devices in mobile scenarios. The current chapter reviews recent
research and standardization work developed under the most used wireless access
technologies and mobile access proposals. It comprehensively outlines the
impact on the deployment of those technologies in future networking
environments, not only on the network performance but also in how the most
important requirements of several relevant players, such as, content providers,
network operators, and users/terminals can be addressed. Finally, the chapter
concludes referring the most notable aspects in how the environment of future
networks are expected to evolve like technology convergence, service
convergence, terminal convergence, market convergence, environmental awareness,
energy-efficiency, self-organized and intelligent infrastructure, as well as
the most important functional requisites to be addressed through that
infrastructure such as flow mobility, data offloading, load balancing and
vertical multihoming.Comment: In book 4G & Beyond: The Convergence of Networks, Devices and
Services, Nova Science Publishers, 201
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