QoS-aware service continuity in the virtualized edge

5G systems are envisioned to support numerous delay-sensitive applications such as the tactile Internet, mobile gaming, and augmented reality. Such applications impose new demands on service providers in terms of the quality of service (QoS) provided to the end-users. Achieving these demands in mobile 5G-enabled networks represent a technical and administrative challenge. One of the solutions proposed is to provide cloud computing capabilities at the edge of the network. In such vision, services are cloudified and encapsulated within the virtual machines or containers placed in cloud hosts at the network access layer. To enable ultrashort processing times and immediate service response, fast instantiation, and migration of service instances between edge nodes are mandatory to cope with the consequences of user’s mobility. This paper surveys the techniques proposed for service migration at the edge of the network. We focus on QoS-aware service instantiation and migration approaches, comparing the mechanisms followed and emphasizing their advantages and disadvantages. Then, we highlight the open research challenges still left unhandled.publishe

Exploiting Virtual Machine Commonality for Improved Resource Allocation in Edge Networks

5G systems are putting increasing pressure on Telecom operators to enhance users’ experience, leading to the development of more techniques with the aim of improving service quality. However, it is essential to take into consideration not only users’ demands but also service providers’ interests. In this work, we explore policies that satisfy both views. We first formulate a mathematical model to compute End-to-End (E2E) delay experienced by mobile users in Multi-access Edge Computing (MEC) environments. Then, dynamic Virtual Machine (VM) allocation policies are presented, with the objective of satisfying mobile users Quality of Service (QoS) requirements, while optimally using the cloud resources by exploiting VM resource reuse.Thus, maximizing the service providers’ profit should be ensured while providing the service required by users. We further demonstrate the benefits of these policies in comparison with previous works

Mobilidade em redes de telecomunicações definidas por software

The 5G networks, and those that follow, are facing an unprecedented increase in mobile data traffic, along with the rising need to support complex, latencyintolerant services. This has prompted telecommunication service providers to seek novel paradigms and techniques to accommodate their customers’ demands and enable novel Quality of Service aware services for mobile users. The Virtualized Edge concept is one of the most promising platforms envisioned as an enabler for delay-sensitive services in future systems. These platforms intend to support latency-aware services by getting resources and computing capabilities closer to the user equipment, placing them on the network edge. Implementing solutions like these brings a new set of challenges. The near-user deployment directly exposes the services to clients’ mobility and to sudden topology changes, making mobility management more challenging, and calling for careful service and resource orchestration to preserve the Service Level Agreement. To facilitate mobility management, novel techniques have been suggested as complementary methods to support mobility and enable latency-intolerant applications alongside the conventional handover procedures. Some of the most relevant techniques includes service instance mobility or migration, optimized low-delay handover, and adaptive and parallel task offloading. In this thesis, we explore different policies and techniques to realize Quality of Service aware services for mobile users, following the paradigm of a virtualized access network. We incorporate these techniques into a orchestration and management layer, adequate to the virtualization of resources in this environment.As redes 5G e além enfrentam uma escalada do tráfego móvel, combinada com um aumento da necessidade de suportar serviços complexos e intolerantes a latência. Isso levou os fornecedores de serviço de telecomunicações, a pesquisar novos paradigmas e técnicas para acomodar os requisitos dos seus clientes, permitindo não apenas serviços contínuos, mas também mecanismos e serviços com características de Qualidade de Serviço adequadas aos utilizadores móveis. As redes de acesso com virtualização são uma das plataformas mais promissoras, constituindo um das principais soluções para o suporte de serviços sensíveis a latência em sistemas futuros. Estas plataformas visam oferecer suporte a serviços sensíveis a latência, aproximando os recursos e capacidades de computação em nuvem do equipamento dos clientes, colocando estes serviços na rede de acesso. Implementar soluções desta natureza também traz novos desafios. Um aprovisionamento próximo do utilizador expõe os serviços diretamente à mobilidade dos clientes móveis, assim como às mudanças repentinas de topologia, aumentando os desafios das soluções de gestão de mobilidade, e exigindo uma orquestração de serviço rigorosa para preservar os níveis de serviço contratados. Para facilitar esta nova gestão de mobilidade, foram sugeridas novas técnicas, como métodos complementares para oferecer suporte à mobilidade e permitir a coexistência de mecanismos típicos de transferência de recursos virtuais com aplicações intolerantes à latência. Algumas destas soluções são, mobilidade ou migração das instâncias virtualizadas, mobilidade otimizada de baixa latência e transferência de tarefas de processamento de forma paralela e adaptável às condições de rede. Nesta tese, são exploradas diferentes políticas e técnicas para realizar serviços, com suporte de Qualidade de Serviço, para utilizadores móveis, quando inseridos num paradigma de virtualização na rede de acesso. São também incorporadas essas técnicas numa camada de orquestração adequada à virtualização de recursos neste ambiente.Programa Doutoral em Telecomunicaçõe

Selective reprogramming of WSNs: energetic study and functionality optimization

Dissertação de mestrado em Engenharia de Redes e Serviços TelemáticosWireless sensors networks consist of large numbers of small, battery-powered, self-organizing computing motes. Nowadays, these networks are considered ideal candidates for a wide range of applications such as environmental monitoring, military operations and other application fields where it is hard to maintain a continuous presence of human beings. Online remote reprogramming is usually carried out to update the code running on nodes due to factors such as changes in the environment or application. Remote reprogramming might be applied to the whole network or just to a subset of nodes (selective reprogramming), either way it is crucial to provide reliability for such procedure. Therefore, most of the approaches oriented to remote reprogramming resort to flooding the whole network, leading to a major waste of energy in network nodes. When dealing with selective reprogramming, the waste of energy increases steeply even when just a small number of nodes need to get the update messages. These messages may be received and retransmitted from all nodes in the network resulting in a waste of resources. This research identifies multiple scenarios for selective reprogramming and proposes a different energy-aware approach for each one trying to reduce energy consumption in the network by taking advantage of multiple and complementary solutions such as wise routing, clustering and the ability to manage nodes sleeping time instead of using the typical flooding approach. These approaches were tested and compared with typical flooding and Deluge solutions. The results show a significant reduction of the power consumption, thus, making the selective remote reprogramming more energy-efficient

Improving energy-awareness in selective reprogramming of WSNs

Saving energy is considered one of the main challenges in wireless sensor networks (WSNs), being radio activities such as message transmission/reception and idle listening the main factors of energy consumption in the nodes. These activities increase with the increase of reliability level required, which is usually achieved through flooding strategies. Procedures such as remote WSNs reprogramming require high-level of reliability leading to an increase in radio activity and, consequently, waste of energy. This energy waste is magnified when dealing with selective reprogramming where only few nodes need to receive the code updates. The main focus of this paper is on improving energy efficiency during selective reprogramming of WSNs, taking advantage of wise routing, decreasing the nodes' idle listening periods and using multiple cooperative senders instead of a single one. The proposed strategies are a contribution toward deploying energy-aware selective reprogramming in WSNs.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC /00319/2013.info:eu-repo/semantics/publishedVersio

Handover prediction integrated with service migration in 5G systems

As the research community inclines toward adopting increasingly complex techniques for future networks, and simple methods are often ignored, being labeled as trivial. In this paper, we argue that simple methods can sometimes outperform more sophisticated ones. We demonstrate that by evaluating two prediction mechanisms to forecast mobile user's handovers exploiting user-network association patterns. We perform a series of experiments on real-world data, evaluating the performance characteristics of such methods over more sophisticated and complex prediction techniques. Furthermore, we discuss how to easily bootstrap these mechanisms into the 5G network architecture. We suggest the use of these methods associated with Multi-access Edge Computing (MEC) scenarios, as a mean to identify favorable edge nodes to host the mobile applications, to best provide continuous and QoS-aware service for mobile users.publishe

Wireless Outdoor Network Planning for a Smart City Pilot

This paper detail the process of radio frequency network planning and design for PASMO pilot project, an open living lab for cooperative ITS and smart cities, starting from analyzing the network and users requirements, going through choosing the appropriate technologies and equipments, and finally testing and validating the feasibility of the proposed deployment plan. Other important outcome of this work is a detailed map of the data rates and signal strength for different radio technologies, supporting the design of robust locationaware communication mechanisms.publishe