40 research outputs found
Extended Mobility Management and Geocast Routing for Internet-to-VANET Multicasting
International audienceEmerging ITS applications, such as point of interest distribution, require information delivery from the Internet to a group of vehicles. Such an Internet-to-VANET multicast service raises several challenges including efficient multicast mobility management and multicast message delivery in a geographic area (geocast). In this paper we propose to extend the PMIP (Proxy Mobile IP) mobility management scheme such that it allows vehicles in a geographic area to subscribe to the multicast group with low control overhead by exploiting vehicular ad hoc networking. We then propose Melody, a geocast routing protocol, which extends the multicast service coverage in the VANET based on overlay routing. Our simulation results show that Melody provides an improved communication performance in urban areas in comparison to geographic flooding
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IP multicast receiver mobility support using PMIPv6 in a global satellite network
YesA new generation of satellite systems that support regenerative on-board processors (OBPs) and multiple spot beam technology have opened new and efficient possibilities of implementing IP multicast communication over satellites. These new features have widened the scope of satellite-based applications and also enable satellite operators to efficiently utilize their allocated bandwidth resources. This makes it possible to provide cost effective satellite network services. IP multicast is a network layer protocol designed for group communication to save bandwidth resources and reduce processing overhead on the source side. The inherent broadcast nature of satellites, their global coverage (air, land, and sea), and direct access to a large number of subscribers imply satellites have unrivalled advantages in supporting IP multicast applications. IP mobility support in general and IP mobile multicast support in particular on mobile satellite terminals like the ones mounted on long haul flights, maritime vessels, continental trains, etc., still remain big challenges that have received very little attention from the research community. This paper proposes how Proxy Mobile IPv6 (PMIPv6)-based IP multicast mobility support defined for terrestrial networks can be adopted and used to support IP mobile multicast in future satellite networks, taking cognizance of the trend in the evolution of satellite communications
Distribuição de vídeo para grupos de utilizadores em redes móveis heterogéneas19
The evolutions veri ed in mobile devices capabilities (storage capacity, screen
resolution, processor, etc.) over the last years led to a signi cant change
in mobile user behavior, with the consumption and creation of multimedia
content becoming more common, in particular video tra c. Consequently,
mobile operator networks, despite being the target of architectural evolutions
and improvements over several parameters (such as capacity, transmission
and reception performance, amongst others), also increasingly become more
frequently challenged by performance aspects associated to the nature of
video tra c, whether by the demanding requirements associated to that
service, or by its volume increase in such networks.
This Thesis proposes modi cations to the mobile architecture towards a more
e cient video broadcasting, de ning and developing mechanisms applicable
to the network, or to the mobile terminal. Particularly, heterogeneous
networks multicast IP mobility supported scenarios are focused, emphasizing
their application over di erent access technologies. The suggested changes
are applicable to mobile or static user scenarios, whether it performs the role
of receiver or source of the video tra c. Similarly, the de ned mechanisms
propose solutions targeting operators with di erent video broadcasting goals,
or whose networks have di erent characteristics. The pursued methodology
combined an experimental evaluation executed over physical testbeds,
with the mathematical evaluation using network simulation, allowing the
veri cation of its impact on the optimization of video reception in mobile
terminalsA evolução veri cada nas características dos dispositivos moveis (capacidade
de armazenamento, resolução do ecrã, processador, etc.) durante os
últimos anos levou a uma alteração signi cativa nos comportamentos dos
utilizadores, sendo agora comum o consumo e produção de conteúdos
multimédia envolvendo terminais móveis, em particular o tráfego vídeo.
Consequentemente, as redes de operador móvel, embora tendo também sido
alvo constante de evoluções arquitecturais e melhorias em vários parâmetros
(tais como capacidade, ritmo de transmissão/recepção, entre outros), vêemse
cada vez mais frequentemente desa adas por aspectos de desempenho
associados à natureza do tráfego de vídeo, seja pela exigência de requisitos
associados a esse serviço, quer pelo aumento do volume do mesmo nesse
tipo de redes.
Esta Tese propôe alterações à arquitetura móvel para a disseminação de vídeo
mais e ciente, de nindo e desenvolvendo mecanismos aplicáveis à rede, ou
ao utilizador móvel. Em particular, são focados cenários suportados por IP
multicast em redes móveis heterogéneas, isto é, com ênfase na aplicação
destes mecanismos sobre diferentes tecnologias de acesso. As alterações
sugeridas aplicam-se a cenários de utilizador estático ou móvel, sendo este a
fonte ou receptor do tráfego vídeo. Da mesma forma, são propostas soluções
tendo em vista operadores com diferentes objectivos de disseminação de
vídeo, ou cujas redes têm diferentes características. A metodologia utilizada
combinou a avaliação experimental em testbeds físicas com a avaliação
matemática em simulações de redes, e permitiu veri car o impacto sobre
a optimização da recepção de vídeo em terminais móveisPrograma Doutoral em Telecomunicaçõe
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IP Mobile Multicast over Next Generation Satellite Networks. Design and Evaluation of a Seamless Mobility Framework for IP Multicast Communications over a Multi-beam Geostationary Satellite Network
The inherent broadcast nature of satellites, their global coverage and direct
access to a large number of subscribers give satellites unrivalled advantages in
supporting IP multicast applications. A new generation of satellite systems that
support regenerative on-board processors and multiple spot beam technology
have opened new possibilities of implementing IP multicast communication over
satellites. These new features enable satellites to make efficient use of their
allocated bandwidth resources and provide cost effective network services but
equally, create new challenges for mobile satellite terminals. IP mobility support
in general and IP mobile multicast support in particular on mobile satellite
terminals like the ones mounted on continental flights, maritime vessels, etc.,
still remain big challenges that have received very little attention from the
research community.
Up till now, there are no proposed mechanisms to support IP multicast for
mobile receivers/sources in multi-beam satellite networks in open literature.
This study explores the suitability of IP multicast mobility support schemes
defined for terrestrial networks in a satellite environment and proposes novel
schemes based on the concepts of Home and Remote subscription-based approaches, multiple interface and PMIPv6 protocol. Detailed analysis and
comparison of results obtained from the proposed schemes, Mobile IP (MIP)
Home and Remote subscription-based approaches (for terrestrial networks)
when implemented on a reference multi-beam satellite network are presented.
From these results, the proposed schemes outperform the MIP Home and
Remote subscription-based approaches in terms of gateway handover latency,
number of multicast packets lost and signalling cost over the satellite air
interface
A network-based coordination design for seamless handover between heterogeneous wireless networks
Includes bibliographical references (leaves 136-144).The rapid growth of mobile and wireless communication over the last few years has spawned many different wireless networks. These heterogeneous wireless networks are envisioned to interwork over an IP-based infrastructure to realize ubiquitous network service provisioning for mobile users. Moreover, the availability of multiple-interface mobile nodes (MNs) will make it possible to communicate through any of these wireless access networks. This wireless network heterogeneity combined with the availability of multiple-interface MNs creates an environment where handovers between the different wireless access technologies become topical during mobility events. Therefore, operators with multiple interworking heterogeneous wireless networks will need to facilitate seamless vertical handovers among their multiple systems. Seamless vertical handovers ensure ubiquitous continuity to active connections hence satisfy the quality of experience of the mobile users
Descoberta de serviços independentes do acesso para redes heterogéneas
Mestrado em Engenharia de Computadores e TelemáticaA recente proliferação de nós móveis com múltiplas interfaces sem fios e a constituição de ambientes heterogéneos possibilitaram a criação de cenários complexos onde os operadores de rede necessitam de disponibilizar conectividade para diferentes tipos de redes de acesso. Assim, a norma IEEE 802.21 foi especificada de forma a facilitar e optimizar os procedimentos de handover entre diferentes tecnologias de acesso sem perda de conectividade.
Para cumprir o seu propósito, a norma disponibiliza serviços chamados Media Independent Handover e que permitem o controlo e a obtenção de informação de diferentes ligações. A configuração estática destes serviços por parte do nó móvel torna-se ineficiente devido aos múltiplos cenários possíveis. Desta forma, o nó móvel deve descobrir nós da rede
que providenciem serviços de mobilidade e as suas capacidade de uma forma dinâmica. Nesta dissertação, um conjunto de mecanismos para descoberta de serviços de handover independentes do acesso são analisados, implementados e avaliados em termos de duração e quantidade de informação trocada. Um novo mecanismo de descoberta de entidades locais
é também proposto e avaliado, demonstrando que a sua utilização aumenta o desempenho e requer a troca de menos quantidade de informação.The recent proliferation of mobile nodes with multiple wireless interfaces,
in addition to the creation of heterogeneous environments, created complex
scenarios where network operators need to provide connectivity for di erent
kinds of access networks. Therefore, the IEEE 802.21 standard has been
speci ed to facilitate and optimize handover procedures between di erent
access technologies in a seamless way. To ful l its purpose, it provides Media
Independent Handover services which allow the control and gathering of
information from di erent links. The static con guration of these services by
the MN becomes ine cient due to the amount of possible scenarios. Thus,
the MN must discover the network-supporting nodes and their capabilities
in a dynamic way. In this work, a series of proposed Media Independent
Handover discovery procedures are analyzed, implemented and evaluated
in terms of duration and amount of exchanged information. In addition,
a novel discovery procedure for local entities is proposed and evaluated,
showing that its deployment increases the performance and requires less
information exchanged