A QoS-enabled resource management scheme for F-HMIPv6 micro mobility approach

In the near future, wireless networks will certainly run real-time applications with special Quality of Service (QoS) requirements. In this context micro mobility management schemes such as Fast Handovers over Hierarchical Mobile IPv6 (F-HMIPv6) will be a useful tool in reducing Mobile IPv6 (MIPv6) handover disruption and thereby to improve delay and losses. However, F-HMIPv6 alone does not support QoS requirements for real-time applications. Therefore, in order to accomplish this goal, a novel resource management scheme for the Differentiated Services (DiffServ) QoS model is proposed to be used as an add-on to F-HMIPv6. The new resource management scheme combines the F-HMIPv6 functionalities with the DiffServ QoS model and with network congestion control and dynamic reallocation mechanisms in order to accommodate different QoS traffic requirements. This new scheme based on a Measurement-Based Admission Control (MBAC) algorithm is effective, simple, scalable and avoids the well known traditional resource reservation issues such as state maintenance, signaling overhead and processing load. By means of the admission evaluation of new flows and handover flows, it is able to provide the desired QoS requirements for new flows while preserving the QoS of existing ones. The evaluated results show that all QoS metrics analyzed were significantly improved with the new architecture indicating that it is able to provide a highly predictive QoS support to F-HMIPv6

A micro-mobility solution for supporting QoS in global mobility

Today, users want to have simultaneously mobility, Quality of Service (QoS) and be always connected to Internet. Therefore, this paper proposes a QoS micro-mobility solution able to provide QoS support for global mobility. The solution comprises enhancements in the mobility management of Mobile IPv6 (MIPv6) and in the resources management of Differentiated Services (DiffServ) QoS model. The mobility management of MIPv6 was extended with fast and local handovers to improve its efficiency in micro-mobility scenarios with frequent handovers. The DiffServ resource management has been extended with adaptive and dynamic QoS provisioning to improve resources utilization in mobile IP networks. Further, in order to improve resources utilization the mobility and QoS messages were coupled, providing a resource management able to, proactively, react to mobile events. The performance improvement of the proposed solution and the model parametrization was evaluated using a simulation model. Simulation results indicate that the solution avoids network congestion and starvation of less priority DiffServ classes. Moreover, the results also indicate that bandwidth utilization for priority classes increases and the QoS offered to MN's applications, in each DiffServ class, keeps up unchangeable with MN mobility.(undefined

Optimization of BGP Convergence and Prefix Security in IP/MPLS Networks

Multi-Protocol Label Switching-based networks are the backbone of the operation of the Internet, that communicates through the use of the Border Gateway Protocol which connects distinct networks, referred to as Autonomous Systems, together. As the technology matures, so does the challenges caused by the extreme growth rate of the Internet. The amount of BGP prefixes required to facilitate such an increase in connectivity introduces multiple new critical issues, such as with the scalability and the security of the aforementioned Border Gateway Protocol. Illustration of an implementation of an IP/MPLS core transmission network is formed through the introduction of the four main pillars of an Autonomous System: Multi-Protocol Label Switching, Border Gateway Protocol, Open Shortest Path First and the Resource Reservation Protocol. The symbiosis of these technologies is used to introduce the practicalities of operating an IP/MPLS-based ISP network with traffic engineering and fault-resilience at heart. The first research objective of this thesis is to determine whether the deployment of a new BGP feature, which is referred to as BGP Prefix Independent Convergence (PIC), within AS16086 would be a worthwhile endeavour. This BGP extension aims to reduce the convergence delay of BGP Prefixes inside of an IP/MPLS Core Transmission Network, thus improving the networks resilience against faults. Simultaneously, the second research objective was to research the available mechanisms considering the protection of BGP Prefixes, such as with the implementation of the Resource Public Key Infrastructure and the Artemis BGP Monitor for proactive and reactive security of BGP prefixes within AS16086. The future prospective deployment of BGPsec is discussed to form an outlook to the future of IP/MPLS network design. As the trust-based nature of BGP as a protocol has become a distinct vulnerability, thus necessitating the use of various technologies to secure the communications between the Autonomous Systems that form the network to end all networks, the Internet

Optical Camera Communications: Principles, Modulations, Potential and Challenges

Optical wireless communications (OWC) are emerging as cost-effective and practical solutions to the congested radio frequency-based wireless technologies. As part of OWC, optical camera communications (OCC) have become very attractive, considering recent developments in cameras and the use of fitted cameras in smart devices. OCC together with visible light communications (VLC) is considered within the framework of the IEEE 802.15.7m standardization. OCCs based on both organic and inorganic light sources as well as cameras are being considered for low-rate transmissions and localization in indoor as well as outdoor short-range applications and within the framework of the IEEE 802.15.7m standardization together with VLC. This paper introduces the underlying principles of OCC and gives a comprehensive overview of this emerging technology with recent standardization activities in OCC. It also outlines the key technical issues such as mobility, coverage, interference, performance enhancement, etc. Future research directions and open issues are also presented

A QoS-aware architecture for mobile internet

Tese de doutoramento InformáticaHoje em dia, as pessoas pretendem ter simultaneamente mobilidade, qualidade de serviço e estar sempre connectados à Internet. No intuito, de satisfazer estes clientes muito exigentes, os mercados das telecomunicações estão a impor novos e dificeis desafios às redes móveis, através da demanda, de heterogeneidade em termos de tecnologias de acesso rádio, novos serviços, niveis de qualidade de serviço adequados aos requisitos das aplicações de tempo real, elevada taxa de utilização do recursos disponiveis e melhor capacidade de desempenho. A Internet foi concebida para fornecer serviços sem qualquer tipo de garantias de qualidade às aplicações, apenas se comprometendo em oferecer o melhor serviço possível. No entanto, nos útlimos anos diversos esforços foram levados a cabo no sentido de dotar a Internet com o suporte à qualidade de serviço. Dos esforços desenvolvidos resultaram dois paradigmas para o suporte da qualidade de serviço: o modelo de Serviços Integrados (Integrated Services - IntServ) e o modelo de Serviços Diferenciados (Differentiated Services - DiffServ). Todavia, estes modelos de qualidade de serviço (QoS) foram concebido antes da existência da Internet móvel, portanto o desenvolvimento destes modelos não teve em consideração a questão da mobilidade. Por outro lado, o protocolo padrão actual para a Internet móvel, o MIPv6, revela algumas limitações nos cenários onde os utilizadores estão constantemente a moverem-se para outros pontos de acesso. Neste tipo de cenários, o MIPv6 introduz tempos de latência que não são sustentáveis para aplicações com requisitos de QoS mais restritos. Os factos revelados, demonstram que existe uma emergente necessidade de adaptar o actual protocolo de mobilidade, e também de adaptar os modelos de QoS, ou então criar modelos alternativos de QoS, para satisfazer às exigências do utilizador de hoje de redes móveis. Para alcançar este objectivo o presente trabalho propõe melhorias no sistema de gestão da mobilidade do protocolo MIPv6 e na gestão de recursos do modelo DiffServ. O MIPv6 foi melhorado para os cenários de micro-mobilidade com a abordagem para micro-mobilidade do F-HMIPv6. Enquanto que, o modelo DiffServ foi melhorado para os ambientes móveis com funcionalidades dinâmicas e adaptativas através da utilização de sinalização de QoS e da gestão distribuida dos recursos. A gestão da mobilidade e dos recursos foi também acoplada na solução proposta com o propósito de optimizar a utilização dos recursos num meio onde os recursos são tipicamente escassos. O modelo proposto é simples, é de fácil implementação, tem em consideração os requisitos da Internet móvel, e provou ser eficiente e capaz de fornecer serviços com QoS de elevada fiabilidade às aplicações.Over the last few years, several network communication challenges have arisen as a result of the growing number of users demanding Quality of Service (QoS) and mobility simultaneously. In order to satisfy these very demanding customers, the markets are imposing new challenges to wireless networks by demanding heterogeneity in terms of wireless access technologies, new services, suited QoS levels to real-time applications, high usability and improved performance. However, the Internet has been designed for providing application services without quality guarantees. That explains why, in the last years several efforts have been made to endow Internet with QoS support. From the developed efforts have resulted two QoS paradigms: Integrated Services (IntServ) which offers the guaranteed service model and the Differentiated Services (DiffServ) which offers the predictive service model. Although these QoS models have been designed before the existence of mobile Internet, so they do not consider the mobility issue. For instance, the guaranteed service model requires that whenever a Mobile Node (MN) wants to move to a new location, the allocated resources in the old path must be released and a new resource reservation in a new path must be made, resulting in extra signaling overhead, heavy processing and state load. Therefore, if handovers are frequent, large mobility and QoS signaling messages will be created in the access networks. Consequently, significant scalability problems may arise with this type of service model. The predicted service model, on the other hand, requires an additional features such as dynamic and adaptive resource management in order to be efficient in a very dynamic network such as a mobile network. A QoS solution for mobile environments must provide the capacity to adapt its resource utilization to a changeable nature of wireless networks because they have a more dynamic behavior due to incoming or outgoing handovers. For this reason, a QoS signalization for dynamic resource provisioning is necessary in order to supply adequate QoS levels to mobile users. On the other hand, the current standard protocol for mobile Internet, Mobile IPv6 (MIPv6), reveals limitations in scenarios where users are constantly moving to another point of attachment. In these situations, MIPv6 introduces latency times that are not sustainable for applications with strict QoS requirements. All things considered, reveal the emerging need to adapt the current standard mobility protocol and QoS models to satisfy today’s mobile user’s requirements. To accomplish this goal, the present work proposes enhancements in terms of the MIPv6 protocol mobility management scheme as well as in DiffServ QoS model resource management. The former was enhanced for micro-mobility scenarios with a specific combination of FMIPv6 (Fast Mobile IPv6) and HMIPv6 (Hierarchical Mobile IPv6) protocols. Whereas, the latter was enhanced for mobile environments with dynamic and adaptive features by using QoS signalization as well as distributed resource management. The mobility and resource management has also been coupled in the proposed solution with the objective of optimizing the resource utilization in a environment where resources are typically scarce. In order to assess model performance as well as its parametrization, a simulation model has been designed and implemented in the Network Simulator version two (NS-2). The model´s performance evaluation has been conducted based on the respective data acquired from statistical analysis in order to validate and consolidate the conclusions. Simulation results indicate that the solution avoids network congestion and starvation of less priority DiffServ classes. Moreover, the results also indicate that bandwidth utilization for priority classes increases and the QoS offered to MN’s applications, in each DiffServ class, remains unchangeable with MN mobility. The proposed model is simple and easy to implement. It considers mobile Internet requirements and has proven to be effective and capable of providing services with highly reliable QoS to mobile applications.Fundação para a Ciência e a Tecnologia (FCT) - Bolsa SFRH/BD/35245/200

Towards a proper service placement in combined Fog-to-Cloud (F2C) architectures

The Internet of Things (IoT) has empowered the development of a plethora of new services, fueled by the deployment of devices located at the edge, providing multiple capabilities in terms of connectivity as well as in data collection and processing. With the inception of the Fog Computing paradigm, aimed at diminishing the distance between edge-devices and the IT premises running IoT services, the perceived service latency and even the security risks can be reduced, while simultaneously optimizing the network usage. When put together, Fog and Cloud computing (recently coined as fog-to-cloud, F2C) can be used to maximize the advantages of future computer systems, with the whole greater than the sum of individual parts. However, the specifics associated with cloud and fog resource models require new strategies to manage the mapping of novel IoT services into the suitable resources. Despite few proposals for service offloading between fog and cloud systems are slowly gaining momentum in the research community, many issues in service placement, both when the service is ready to be executed admitted as well as when the service is offloaded from Cloud to Fog, and vice-versa, are new and largely unsolved. In this paper, we provide some insights into the relevant features about service placement in F2C scenarios, highlighting main challenges in current systems towards the deployment of the next-generation IoT servicesPostprint (author's final draft

IP and ATM integration: A New paradigm in multi-service internetworking

ATM is a widespread technology adopted by many to support advanced data communication, in particular efficient Internet services provision. The expected challenges of multimedia communication together with the increasing massive utilization of IP-based applications urgently require redesign of networking solutions in terms of both new functionalities and enhanced performance. However, the networking context is affected by so many changes, and to some extent chaotic growth, that any approach based on a structured and complex top-down architecture is unlikely to be applicable. Instead, an approach based on finding out the best match between realistic service requirements and the pragmatic, intelligent use of technical opportunities made available by the product market seems more appropriate. By following this approach, innovations and improvements can be introduced at different times, not necessarily complying with each other according to a coherent overall design. With the aim of pursuing feasible innovations in the different networking aspects, we look at both IP and ATM internetworking in order to investigating a few of the most crucial topics/ issues related to the IP and ATM integration perspective. This research would also address various means of internetworking the Internet Protocol (IP) and Asynchronous Transfer Mode (ATM) with an objective of identifying the best possible means of delivering Quality of Service (QoS) requirements for multi-service applications, exploiting the meritorious features that IP and ATM have to offer. Although IP and ATM often have been viewed as competitors, their complementary strengths and limitations from a natural alliance that combines the best aspects of both the technologies. For instance, one limitation of ATM networks has been the relatively large gap between the speed of the network paths and the control operations needed to configure those data paths to meet changing user needs. IP\u27s greatest strength, on the other hand, is the inherent flexibility and its capacity to adapt rapidly to changing conditions. These complementary strengths and limitations make it natural to combine IP with ATM to obtain the best that each has to offer. Over time many models and architectures have evolved for IP/ATM internetworking and they have impacted the fundamental thinking in internetworking IP and ATM. These technologies, architectures, models and implementations will be reviewed in greater detail in addressing possible issues in integrating these architectures s in a multi-service, enterprise network. The objective being to make recommendations as to the best means of interworking the two in exploiting the salient features of one another to provide a faster, reliable, scalable, robust, QoS aware network in the most economical manner. How IP will be carried over ATM when a commercial worldwide ATM network is deployed is not addressed and the details of such a network still remain in a state of flux to specify anything concrete. Our research findings culminated with a strong recommendation that the best model to adopt, in light of the impending integrated service requirements of future multi-service environments, is an ATM core with IP at the edges to realize the best of both technologies in delivering QoS guarantees in a seamless manner to any node in the enterprise

Toward Distributed At-scale Hybrid Network Test with Emulation and Simulation Symbiosis

In the past decade or so, significant advances were made in the field of Future Internet Architecture (FIA) design. Undoubtedly, the size of Future Internet will increase tremendously, and so will the complexity of its users’ behaviors. This advancement means most of future Internet applications and services can only achieve and demonstrate full potential on a large-scale basis. The development of network testbeds that can validate key design decisions and expose operational issues at scale is essential to FIA research. In conjunction with the development and advancement of FIA, cyber-infrastructure testbeds have also achieved remarkable progress. For meaningful network studies, it is indispensable to utilize cyber-infrastructure testbeds appropriately in order to obtain accurate experiment results. That said, existing current network experimentation is intrinsically deficient. The existing testbeds do not offer scalability, flexibility, and realism at the same time. This dissertation aims to construct a hybrid system of conducting at-scale network studies and experiments by exploiting the distributed computing ability of current testbeds. First, this work presents a synchronization of parallel discrete event simulation that offers the simulation with transparent scalability and performance on various high-end computing platforms. The parallel simulator that we implement is configured so that it can self-adapt for the performance while running on supercomputers with disparate architectures. The simulator could be used to handle models of different sizes, varying modeling details, and different complexity levels. Second, this works addresses the issue of researching network design and implementation realistically at scale, through the use of distributed cyber-infrastructure testbeds. An existing symbiotic approach is applied to integrate emulation with simulation so that they can overcome the limitations of physical setup. The symbiotic method is used to improve the capabilities of a specific emulator, Mininet. In this case, Mininet can be used to run applications directly on the virtual machines and software switches, with network connectivity represented by detailed simulation at scale. We also propose a method for using the symbiotic approach to coordinate separate Mininet instances, each representing a different set of the overlapping network flows. This approach provides a significant improvement to the scalability of the network experiments