9 research outputs found
Mecanismos de facturação segura em redes auto-organizadas
Mestrado em Engenharia Electrónica e TelecomunicaçõesAs redes ad-hoc e as redes auto-organizadas constituem uma área de investigação com grande interesse. Estas redes são uteis em cenários onde
seja necessária uma rede de baixo custo, elevada adaptabilidade e reduzido
tempo de criação. As redes infra-estruturadas, tendo uma gestão
centralizada, estão agora a começar a adoptar os conceitos de redes autoorganizadas
nas suas arquitecturas. Ao contrário dos sistemas centralizados,
redes auto-organizadas requerem que todos os terminais participantes operem
de acordo com o melhor interesse da rede. O facto de, em redes ad-hoc,
os equipamentos possuírem recursos limitados, pôe em causa este requisito
levando a comportamentos egoístas. Este comportamento é espectavel criando
problemas nas redes auto-organizativas, ameaçando o funcionamento
de uma rede inteira. Algumas propostas foram ja criadas de modo a motivar
a sua utilização correcta. Destas, algumas são baseadas em trocas de
credito entre utilizadores, outras preveêm a existência de entidades gestoras
de creditos. Estas ultimas propostas, que irão ser o foco desta dissertação,
permitem a facil integração de redes ad-hoc com redes infra-estruturadas e
geridas por um operador. Este trabalho descreve o estado da arte actual e,
com algum detalhe, os métodos utilizados e as solucões relevantes para esta
area. São propostas duas novas soluções de taxação para estas redes. Ambas
as soluções possibilitam a integração das redes com metodos de taxação
habituais em redes geridas por operadores. Para além disto, a motivação
à participaçãao é aumentada através de incentivos ao encaminhamento de
pacotes. Todos os processos são criptograficamente seguros através da utilização de métodos standard como DSA sobre Curvas Elípticas e funções de
síntese robustas. As soluções propostas são descritas analiticamente e analisadas,
sendo os os resultados obtidos comparados com outra proposta do
estado da arte. Um exaustivo trabalho de simulação é igualmente descrito
de forma a avaliar as soluções em cenários mais complexos. Os resultados
obtidos em simulação são avaliados tendo em conta a variação de várias
métricas como mobilidade, carga na rede, protocolo de encaminhamento e
protocolo de transporte. No final, a arquitectura, implementação e resultados
obtidos com uma implementação real de uma das propostas e os seus
resultados analisados.Self-organised and ad-hoc networks are an area with an existing large research
community. These networks are much useful in scenarios requiring
a rapidly deployed, low cost and highly adaptable network. Recently, infrastructure
networks, which are managed in a much centralised form, are
starting to introduce concepts of self-organised networks in its architecture.
In opposition to centralised systems, self-organisation creates the necessity
for all nodes to behave according to the best interest of the network. The
fact that in many ad-hoc networks nodes have scarce resources poses some
threats to this requirement. As resources decreases, such as battery or wireless
bandwidth, nodes can start acting selfishly. This behaviour is known to
bring damage to self-organised networks and threatens the entire network.
Several proposals were made in order to promote the correct usage of the
network. Some proposals are based on local information and direct credit
exchange while others envision the existence of a central bank. The later
solutions are further elaborated in this thesis, as they make possible integration
of ad-hoc network with operator driven infrastructures. This work
presents the current state-of-the-art on the area providing a detailed insight
on the methods adopted by each solution presented. Two novel solutions are
proposed providing charging support for integrated ad-hoc networks. Both
solutions provide means of integration with standard management methods
found in operator networks. Also, node´s motivation is increased through
the reward of nodes forwarding data packets. The entire process is cryptographically
secure, making use of standard methods such as Elliptic Curve
DSA and strong digest functions. The solutions proposed are described
and analysed analytically, comparing the results with other state-of-the-art
proposals. Extensive simulation work is also presented which furthers evaluates
the solutions in complex scenarios. Results are obtained from these
scenarios and several metrics are evaluated taking in consideration mobility,
network load, routing protocol and transport protocol. The architecture
and results obtained with a real implementation are finally presented and
analysed
Estabelecimento de redes de comunidades sobreponíveis
Doutoramento em Engenharia InformáticaUma das áreas de investigação em Telecomunicações de interesse crescente
prende-se com os futuros sistemas de comunicações móveis de 4a geração
e além destes. Nos últimos anos tem sido desenvolvido o conceito de redes
comunitárias, no qual os utilizadores se agregam de acordo com interesses
comuns. Estes conceitos têm sido explorados de uma forma horizontal em
diferentes camadas da comunicação, desde as redes comunitárias de comunicação
(Seattle Wireless ou Personal Telco, p.ex.) até às redes de interesses
peer-to-peer. No entanto, estas redes são usualmente vistas como redes de
overlay, ou simplesmente redes de associação livre. Na prática, a noção de
uma rede auto-organizada, completamente orientada ao serviço/comunidade,
integralmente suportada em termos de arquitetura, não existe. Assim este
trabalho apresenta uma realização original nesta área de criação de redes
comunitárias, com uma arquitetura subjacente orientada a serviço, e que suporta
integralmente múltiplas redes comunitárias no mesmo dispositivo, com
todas as características de segurança, confiança e disponibilização de serviço
necessárias neste tipo de cenários (um nó pode pertencer simultaneamente
a mais do que uma rede comunitária). Devido à sua importância para
os sistemas de redes comunitárias, foi dado particular atenção a aspetos de
gestão de recursos e controlo de acessos. Ambos realizados de uma forma
descentralizada e considerando mecanismos dotados de grande escalabilidade.
Para isso, é apresentada uma linguagem de políticas que suporta a
criação de comunidades virtuais. Esta linguagem não é apenas utilizada para
o mapeamento da estrutura social dos membros da comunidade, como para,
gerir dispositivos, recursos e serviços detidos pelos membros, de uma forma
controlada e distribuída.One of the research areas with increasing interest in the field of telecommunications,
are the ones related to future telecommunication systems, both 4th
generation and beyond. In parallel, during the last years, several concepts
have been developed related to clustering of users according to their interested,
in the form of community networks. Solutions proposed for these concepts
tackle the challenges horizontally, for each layer of the communication
stack, ranging from community based communication networks (e.g. Seattle
Wireless, or Personal Telco), to interest networks based on peer-to-peer protocols.
However, these networks are presented either as free joining, or overlay
networks. In practice, the notion of a self-organized, service and community
oriented network, with these principles embedded in its design principles, is
yet to be developed. This work presents an novel instantiation of a solution in
the area of community networks, with a underlying architecture which is fully
service oriented, and envisions the support for multiple community networks
in the same device. Considerations regarding security, trust and service availability
for this type of environments are also taken. Due to the importance of
resource management and access control, in the context of community driven
communication networks, a special focus was given to the support of scalable
and decentralized management and access control methods. For this
purpose, it is presented a policy language which supports the creation and
management of virtual communities. The language is not only used for mapping
the social structure of the community members, but also to, following
a distributed approach, manage devices, resources and services owned by
each community member
User centric community clouds
With the evolution in cloud technologies, users are becoming acquainted with seamless service provision. Nevertheless, clouds are not a user centric technology, and users become completely dependent on service providers. We propose a novel concept for clouds, where users self-organize to create their clouds. We present such an architecture for user-centric clouds, which relies on self-managed clouds based on doctrine and on identity management concepts
Permission and Privacy Challenges in Alternate-Tenant Smart Spaces
We explore a ‘Smart-BnB scenario’ whereby someone (an Owner) advertises a smart property on a web platform. Renters use the platform for short periods, and may fully enjoy the property, including its smart features such as sensors. This scenario should further ensure the Renter’s privacy, so we use consent receipts and selective sharing. This paper describes a demonstrator of how smart environments can operate in a privacy-respecting manner
Smartlighting: a platform for intelligent building management
This work proposes a solution to endow buildings with efficiency and intelligence, exploiting the advantages of Complex Event Processing techniques and Internet of Things (IoT) principles. This combination allows efficient management of the entire infrastructure, an in particular enabling lighting to be tailored to the users needs. We validate this solution through a prototype implementation, based on wireless sensors and actuator networks that interact with the environment, using standard lightweight protocols designed for IoT. The prototype is based on high performance and real time platforms, and complex methods for analysis of large streams of data. The implementation is applied to a real world scenario, and will be used as the standard solution for management and automation of an existing building
SKA telescope manager: a status update
The international Square Kilometre Array (SKA) project to build two radio interferometers is approaching the end of its design phase, and gearing up for the beginning of formal construction. A key part of this distributed Observatory is the overall software control system: the Telescope Manager (TM). The two telescopes, a Low frequency dipole array to be located in Western Australia (SKA-Low) and a Mid-frequency dish array to be located in South Africa (SKA-Mid) will be operated as a single Observatory, with its global headquarters (GHQ) based in the United Kingdom at Jodrell Bank. When complete it will be the most powerful radio observatory in the world. The TM software must combine the observatory operations based at the GHQ with the monitor and control operations of each telescope, covering the range of domains from proposal submission to the coordination and monitoring of the subsystems that make up each telescope. It must also monitor itself and provide a reliable operating platform. This paper will provide an update on the design status of TM, covering the make-up of the consortium delivering the design, a brief description of the key challenges and the top level architecture, and its software development plans for tackling the construction phase of the project. It will also briefly describe the consortium’s response to the SKA Project’s decision in the second half of 2016 to adopt the processes set out by the Software Engineering Institute (SEI) for system architecture design and documentation, including a re-evaluation of its deliverables, documentation and approach to internal reviews.publishe
Permissioning and Personal Data Management in Alternate-Tenancy Smart Environments
We focus on a scenario that we call SmartBnB: smart homes rich in devices that are rented for a short period of time such as holidays. Such frequent rotation of different users raises two types of mutually dependent challenges. First, we have a permissioning challenge since devices are commonly designed with a single user in mind; yet, given our shared scenario, we need to grant the necessary, yet minimum, access to devices and just for the duration of the stay. Secondly, privacy challenges arise given the shared and externally managed nature of the devices (e.g., on the cloud). Other challenges exist such as the lack of user-interfaces that make difficult to serve a privacy notice. This paper discusses how such a familiar scenario can bring stringent requirements. After characterising and discussing the emergent challenges, we present a conservative and bottom-up architecture (e.g., by reusing existing protocols) that we evaluate on a realistic scenario. We conclude that, while it is able to meet current functional requirements, a SmartBnB scenario raises technical gaps
CISMOB - Cooperative information platform for low carbon and sustainable mobility: pilot action: survey results and policy guidelines
Sem resumo disponível.publishe
Permissioning and Personal Data Management in Alternate-Tenancy Smart Environments
We focus on a scenario that we call SmartBnB: smart homes rich in devices that are rented for a short period of time such as holidays. Such frequent rotation of different users raises two types of mutually dependent challenges. First, we have a permissioning challenge since devices are commonly designed with a single user in mind; yet, given our shared scenario, we need to grant the necessary, yet minimum, access to devices and just for the duration of the stay. Secondly, privacy challenges arise given the shared and externally managed nature of the devices (e.g., on the cloud). Other challenges exist such as the lack of user-interfaces that make difficult to serve a privacy notice. This paper discusses how such a familiar scenario can bring stringent requirements. After characterising and discussing the emergent challenges, we present a conservative and bottom-up architecture (e.g., by reusing existing protocols) that we evaluate on a realistic scenario. We conclude that, while it is able to meet current functional requirements, a SmartBnB scenario raises technical gaps