217 research outputs found
Random Linear Network Coding for 5G Mobile Video Delivery
An exponential increase in mobile video delivery will continue with the
demand for higher resolution, multi-view and large-scale multicast video
services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a
number of new opportunities for optimizing video delivery across both 5G core
and radio access networks. One of the promising approaches for video quality
adaptation, throughput enhancement and erasure protection is the use of
packet-level random linear network coding (RLNC). In this review paper, we
discuss the integration of RLNC into the 5G NR standard, building upon the
ideas and opportunities identified in 4G LTE. We explicitly identify and
discuss in detail novel 5G NR features that provide support for RLNC-based
video delivery in 5G, thus pointing out to the promising avenues for future
research.Comment: Invited paper for Special Issue "Network and Rateless Coding for
Video Streaming" - MDPI Informatio
SDN/NFV-enabled satellite communications networks: opportunities, scenarios and challenges
In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and more flexible integration of satellite and terrestrial segments, providing satellite network further service innovation and business agility by advanced network resources management techniques. Through the analysis of scenarios and use cases, this paper provides a description of the benefits that SDN/NFV technologies can bring into satellite communications towards 5G. Three scenarios are presented and analysed to delineate different potential improvement areas pursued through the introduction of SDN/NFV technologies in the satellite ground segment domain. Within each scenario, a number of use cases are developed to gain further insight into specific capabilities and to identify the technical challenges stemming from them.Peer ReviewedPostprint (author's final draft
Models and Methods for Network Selection and Balancing in Heterogeneous Scenarios
The outbreak of 5G technologies for wireless communications can be considered a response to the need for widespread coverage, in terms of connectivity and bandwidth, to guarantee broadband services, such as streaming or on-demand programs offered by the main television networks or new generation services based on augmented and virtual reality (AR / VR).
The purpose of the study conducted for this thesis aims to solve two of the main problems that will occur with the outbreak of 5G, that is, the search for the best possible connectivity, in order to offer users the resources necessary to take advantage of the new generation services, and multicast as required by the eMBMS.
The aim of the thesis is the search for innovative algorithms that will allow to obtain the best connectivity to offer users the resources necessary to use the 5G services in a heterogeneous scenario. Study UF that allows you to improve the search for the best candidate network and to achieve a balance that allows you to avoid congestion of the chosen networks. To achieve these two important focuses, I conducted a study on the main mathematical methods that made it possible to select the network based on QoS parameters based on the type of traffic made by users. A further goal was to improve the computational computation performance they present.
Furthermore, I carried out a study in order to obtain an innovative algorithm that would allow the management of multicast. The algorithm that has been implemented responds to the needs present in the eMBMS, in realistic scenarios
Middleware de comunicações para a internet móvel futura
Doutoramento em Informática (MAP-I)A evolução constante em novas tecnologias que providenciam suporte à forma como os nossos dispositivos se ligam, bem como a forma como utilizamos diferentes capacidades e serviços on-line, criou um conjunto sem precedentes de novos desafios que motivam o desenvolvimento de uma recente área de investigação, denominada de Internet Futura. Nesta nova área de investigação, novos aspectos arquiteturais estão ser desenvolvidos, os quais, através da re-estruturação de componentes nucleares subjacentesa que compõem a Internet, progride-a de uma forma capaz de não são fazer face a estes novos desafios, mas também de a preparar para os desafios de amanhã. Aspectos chave pertencendo a este conjunto de desafios são os ambientes de rede heterogéneos compostos por diferentes tipos de redes de acesso, a cada vez maior mudança do tráfego peer-to-peer (P2P) como o tipo de tráfego mais utilizado na Internet, a orquestração de cenários da Internet das Coisas (IoT) que exploram mecanismos de interação Maquinaa-Maquina (M2M), e a utilização de mechanismos centrados na informação
(ICN). Esta tese apresenta uma nova arquitetura capaz de simultaneamente
fazer face a estes desafios, evoluindo os procedimentos de conectividade e
entidades envolvidas, através da adição de uma camada de middleware, que
age como um mecanismo de gestão de controlo avançado. Este mecanismo
de gestão de controlo aproxima as entidades de alto nível (tais como
serviços, aplicações, entidades de gestão de mobilidade, operações de encaminhamento, etc.) com as componentes das camadas de baixo nível
(por exemplo, camadas de ligação, sensores e atuadores), permitindo uma
otimização conjunta dos procedimentos de ligação subjacentes. Os resultados
obtidos não só sublinham a flexibilidade dos mecanismos que compoem
a arquitetura, mas também a sua capacidade de providenciar aumentos de
performance quando comparados com outras soluÇÕes de funcionamento
especÍfico, enquanto permite um maior leque de cenáios e aplicações.The constant evolution in new technologies that support the way our devices
are able to connect, as well the way we use available on-line services and capabilities, has created a set of unprecedented new challenges that motivated
the development of a recent research trend known as the Future Internet.
In this research trend, new architectural aspects are being developed which,
through the restructure of underlying core aspects composing the Internet,
reshapes it in a way capable of not only facing these new challenges,
but also preparing it to tackle tomorrow’s new set of complex issues. Key
aspects belonging to this set of challenges are heterogeneous networking
environments composed by di↵erent kinds of wireless access networks, the
evergrowing change from peer-to-peer (P2P) to video as the most used kind
of traffic in the Internet, the orchestration of Internet of Things (IoT) scenarios exploiting Machine-to-Machine (M2M) interactions, and the usage of
Information-Centric Networking (ICN). This thesis presents a novel framework
able to simultaneous tackle these challenges, empowering connectivity
procedures and entities with a middleware acting as an advanced control
management mechanism. This control management mechanism brings together
both high-level entities (such as application services, mobility management
entities, routing operations, etc.) with the lower layer components
(e.g., link layers, sensor devices, actuators), allowing for a joint optimization of the underlying connectivity and operational procedures. Results highlight not only the flexibility of the mechanisms composing the framework, but also their ability in providing performance increases when compared with other specific purpose solutions, while allowing a wider range of scenarios and deployment possibilities
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Interoperability of wireless communication technologies in hybrid networks: Evaluation of end-to-end interoperability issues and quality of service requirements
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Hybrid Networks employing wireless communication technologies have nowadays brought closer the vision of communication “anywhere, any time with anyone”. Such communication technologies consist of various standards, protocols, architectures, characteristics, models, devices, modulation and coding techniques. All these different technologies naturally may share some common characteristics, but there are also many important differences. New advances in these technologies are emerging very rapidly, with the advent of new models, characteristics, protocols and architectures. This rapid evolution imposes many challenges and issues to be addressed, and of particular importance are the interoperability issues of the following wireless technologies: Wireless Fidelity (Wi-Fi) IEEE802.11, Worldwide Interoperability for Microwave Access (WiMAX) IEEE 802.16, Single Channel per Carrier (SCPC), Digital Video Broadcasting of Satellite (DVB-S/DVB-S2), and Digital Video Broadcasting Return Channel through Satellite (DVB-RCS). Due to the differences amongst wireless technologies, these technologies do not generally interoperate easily with each other because of various interoperability and Quality of Service (QoS) issues.
The aim of this study is to assess and investigate end-to-end interoperability issues and QoS requirements, such as bandwidth, delays, jitter, latency, packet loss, throughput, TCP performance, UDP performance, unicast and multicast services and availability, on hybrid wireless communication networks (employing both satellite broadband and terrestrial wireless technologies).
The thesis provides an introduction to wireless communication technologies followed by a review of previous research studies on Hybrid Networks (both satellite and terrestrial wireless technologies, particularly Wi-Fi, WiMAX, DVB-RCS, and SCPC). Previous studies have discussed Wi-Fi, WiMAX, DVB-RCS, SCPC and 3G technologies and their standards as well as their properties and characteristics, such as operating frequency, bandwidth, data rate, basic configuration, coverage, power, interference, social issues, security problems, physical and MAC layer design and development issues. Although some previous studies provide valuable contributions to this area of research, they are limited to link layer characteristics, TCP performance, delay, bandwidth, capacity, data rate, and throughput. None of the studies cover all aspects of end-to-end interoperability issues and QoS requirements; such as bandwidth, delay, jitter, latency, packet loss, link performance, TCP and UDP performance, unicast and multicast performance, at end-to-end level, on Hybrid wireless networks.
Interoperability issues are discussed in detail and a comparison of the different technologies and protocols was done using appropriate testing tools, assessing various performance measures including: bandwidth, delay, jitter, latency, packet loss, throughput and availability testing. The standards, protocol suite/ models and architectures for Wi-Fi, WiMAX, DVB-RCS, SCPC, alongside with different platforms and applications, are discussed and compared. Using a robust approach, which includes a new testing methodology and a generic test plan, the testing was conducted using various realistic test scenarios on real networks, comprising variable numbers and types of nodes. The data, traces, packets, and files were captured from various live scenarios and sites. The test results were analysed in order to measure and compare the characteristics of wireless technologies, devices, protocols and applications.
The motivation of this research is to study all the end-to-end interoperability issues and Quality of Service requirements for rapidly growing Hybrid Networks in a comprehensive and systematic way.
The significance of this research is that it is based on a comprehensive and systematic investigation of issues and facts, instead of hypothetical ideas/scenarios or simulations, which informed the design of a test methodology for empirical data gathering by real network testing, suitable for the measurement of hybrid network single-link or end-to-end issues using proven test tools.
This systematic investigation of the issues encompasses an extensive series of tests measuring delay, jitter, packet loss, bandwidth, throughput, availability, performance of audio and video session, multicast and unicast performance, and stress testing. This testing covers most common test scenarios in hybrid networks and gives recommendations in achieving good end-to-end interoperability and QoS in hybrid networks.
Contributions of study include the identification of gaps in the research, a description of interoperability issues, a comparison of most common test tools, the development of a generic test plan, a new testing process and methodology, analysis and network design recommendations for end-to-end interoperability issues and QoS requirements. This covers the complete cycle of this research.
It is found that UDP is more suitable for hybrid wireless network as compared to TCP, particularly for the demanding applications considered, since TCP presents significant problems for multimedia and live traffic which requires strict QoS requirements on delay, jitter, packet loss and bandwidth. The main bottleneck for satellite communication is the delay of approximately 600 to 680 ms due to the long distance factor (and the finite speed of light) when communicating over geostationary satellites.
The delay and packet loss can be controlled using various methods, such as traffic classification, traffic prioritization, congestion control, buffer management, using delay compensator, protocol compensator, developing automatic request technique, flow scheduling, and bandwidth allocation
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
Internames: a name-to-name principle for the future Internet
We propose Internames, an architectural framework in which names are used to
identify all entities involved in communication: contents, users, devices,
logical as well as physical points involved in the communication, and services.
By not having a static binding between the name of a communication entity and
its current location, we allow entities to be mobile, enable them to be reached
by any of a number of basic communication primitives, enable communication to
span networks with different technologies and allow for disconnected operation.
Furthermore, with the ability to communicate between names, the communication
path can be dynamically bound to any of a number of end-points, and the
end-points themselves could change as needed. A key benefit of our architecture
is its ability to accommodate gradual migration from the current IP
infrastructure to a future that may be a ubiquitous Information Centric
Network. Basic building blocks of Internames are: i) a name-based Application
Programming Interface; ii) a separation of identifiers (names) and locators;
iii) a powerful Name Resolution Service (NRS) that dynamically maps names to
locators, as a function of time/location/context/service; iv) a built-in
capacity of evolution, allowing a transparent migration from current networks
and the ability to include as particular cases current specific architectures.
To achieve this vision, shared by many other researchers, we exploit and expand
on Information Centric Networking principles, extending ICN functionality
beyond content retrieval, easing send-to-name and push services, and allowing
to use names also to route data in the return path. A key role in this
architecture is played by the NRS, which allows for the co-existence of
multiple network "realms", including current IP and non-IP networks, glued
together by a name-to-name overarching communication primitive.Comment: 6 page
Optimização de recursos para difusão em redes de próxima geração
Doutoramento em ElectrotecniaEsta tese aborda o problema de optimização de recursos de rede, na entrega de Serviços de Comunicação em Grupo, em Redes de Próxima Geração que suportem tecnologias de difusão. De acordo com esta problemática, são feitas propostas que levam em atenção a evolução espectável das redes 3G em Redes Heterogéneas de Próxima Geração que incluam tecnologias de difusão tais como o DVB. A optimização de recursos em Comunicações em Grupo é apresentada como um desafio vertical que deve cruzar diversas camadas. As optimizações aqui propostas cobrem tanto a interface entre Aplicação e a Plataforma de Serviços para a disponibilização de serviços de comunicação em grupo, como as abstracções e mapeamentos feitos na interface entre a Rede Central e a Rede de Acesso Rádio. As optimizações propostas nesta tese, assumem que o caminho evolutivo na direcção de uma Rede de Próxima Geração é feito através do IP. Em primeiro lugar são endereçadas as optimizações entre a Aplicação e a Plataforma de Serviços que já podem ser integradas nas redes 3G existentes. Estas optimizações podem potenciar o desenvolvimento de novas e inovadoras aplicações, que através do uso de mecanismos de distribuição em difusão podem fazer um uso mais eficiente dos recursos de rede. De seguida são apresentadas optimizações ao nível da interface entre a Rede Central e a Rede de Acesso Rádio que abordam a heterogeneidade das redes futuras assim como a necessidade de suportar tecnologias de difusão. É ainda considerada a possibilidade de aumentar a qualidade de serviço de serviços de difusão através do mapeamento do IP multicast em portadoras unidireccionais. Por forma a validar todas estas optimizações, vários protótipos foram desenvolvidos com base num router avançado para redes de acesso de próxima geração. As funcionalidades e arquitectura de software desse router são também aqui apresentadas.This thesis addresses the problem of optimizing network resource usage, for the delivery of Group Services, in Next Generation Networks featuring broadcast technologies. In this scope, proposals are made according to the expected evolution of 3G networks into Next Generation Heterogeneous Networks that include broadcast technologies such as DVB. Group Communication resource optimization is considered a vertical challenge that must cross several layers. The optimizations here proposed cover both Application to Service Platform interfaces for group communication services, and Core Network to Radio Access Network interface abstractions and mappings. The proposed optimizations are also presented taking into consideration network evolution path towards an All-IP based Next Generation Network. First it is addressed the Application to Service Platform optimization, which can already be deployed over 3G networks. This optimization could potentiate the development of new and innovative applications that through the use of broadcast/multicast service delivery mechanisms could be more efficient network wise. Next proposals are made on the Core Network to Radio Access Network interfaces that address the heterogeneity of future networks and consider the need to support broadcast networks. It is also considered the possibility to increase the Quality of Service of broadcast/multicast services based on the dynamic mapping of IP multicast into unicast radio bearers. In order to validate these optimizations, several prototypes were built based on an advanced access router for next generation networks. Such access router functionalities and software architecture are also presented here
A new framework for minimising handover in multicast mobility
Nowadays, mobile devices support a variety of multimedia applications such as live video, radio or online gaming. People spend their time on mobile devices for entertainment more and more via the internet. Due to the requirements of multimedia applications over wireless communication those applications require a huge bandwidth on the network to support them, which creates problems for the network provider. However, one pattern that is appropriate for the efficient delivery of multimedia messages is multicast delivery.Multicast services do, however, introduce challenges within the network when the recipients of the service are moving. Powerful multicast routing protocols are designed for static client IP addresses. Hence, when the mobile node changes the location, it introduces the problem of access network handover. Therefore, this is the aim of the research where a new framework will be developed for multicast mobility within WiFi network to reduce and provide smooth mobility when handover occurs. This research is focused on techniques to reduce handover latency, minimize packet loss and provide connection when a user moves between network zones.To achieve these aims, this designed framework lets mobile nodes send the message to register to foreign agents in advance for addressing IP address of the new zone and to establish the multicast tree earlier. Moreover, there are processes that keep the connection of the path alive.The framework is being simulated on OPNET Modeler for evaluating the performance in terms of handover latency time, the number of packet loss and so on. There are many scenarios that have been tested. According to the results, it shows that the new framework has reduced handover latency time around 60% on average and minimized packet delay approximately 0.7 - 150 ms on mobile node depending on network topology. This framework can provide IP address reconfiguration, binding update, joining multicast group and distribution path of multicast tree in advance. However, there are some overheads and cost that this framework has to pay for such as IP address database, increasing broadcast within networks and keeping connection path alive
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