The Internet of Things needs for computing power and storage are expected to remain on the rise in the next decade. Consequently, the amount of data generated by devices at the edge of the network will also grow. While cloud computing has been an established and effective way of acquiring computation and storage as a service to many applications, it may not be suitable to handle the myriad of data from IoT devices and fulfill largely heterogeneous application requirements. Fog computing has been developed to lie between IoT and the cloud, providing a hierarchy of computing power that can collect, aggregate, and process data from/to IoT devices. Combining fog and cloud may reduce data transfers and communication bottlenecks to the cloud and also contribute to reduced latencies, as fog computing resources exist closer to the edge. This paper examines this IoT-Fog-Cloud ecosystem and provides a literature review from different facets of it: how it can be organized, how management is being addressed, and how applications can benefit from it. Lastly, we present challenging issues yet to be addressed in IoT-Fog-Cloud infrastructures. low latency, and mobile applications. The centralized cloud data centers are often physically and/or logically distant from the cloud client, implying communication and data transfers to traverse multiple hops, which introduces delays and consumes network bandwidth of edge and core networks [2].The widespread adoption of cloud computing, combined with the ever increasing ability of edge devices to run heterogeneous applications that generate and consume all kinds of data from a variety of sources, requires novel distributed computing infrastructures that can cope with such heterogeneous application requirements. Computing infrastructures that enact applications at edge devices have started to appear in recent years [3,4], improving aspects such as response time and reducing bandwidth use. Combining the ability of running smaller, localized applications at the edge with the high-capacity from the cloud, fog computing has emerged as an paradigm that can support heterogeneous requirements of small and large applications through multiple layers of a computational infrastructure that combines resources from the edge of the network as well as from the cloud [5].In this paper, we aim at identifying and reviewing the main aspects and challenges that make the combination of fog computing and cloud computing suitable for all kinds of applications leveraged by the Internet of Things. We discuss aspects from the infrastructure (processing, networking, protocols, and infrastructure for 5G support) to applications (smart cities, urban computing, and industry 4.0), passing through the management complexity of the distributed IoT-fog-cloud system (services, resource allocation and optimization, energy consumption, data management and locality, devices federation and trust, and business and service models).In the next section we introduce concepts and definitions for Internet of Things (IoT), cloud computi...

New services and applications become part of our daily activities as we evolve into new solutions supported by cutting-edge paradigms, like the Internet of Things and Smart Cities. In order to properly achieve the benefits theoretically provided by these models, new kinds of services must be designed. These new services have special requirements, as well as the users that access to them. One of these requirements is low latency levels, since a delayed reply could render to chaos for applications such as eHealth and public safety. The communication infrastructure must cope with these challenges by offering innovative solutions. One of these solutions is a smart service placement system that facilitates the location of services in the proper position according to specific needs. On this paper, a service placement architecture for the Internet of Things is proposed, with especial emphasis in its main module, the Service Orchestrator, for which implementation details are provided, including a model for the service placement task. Furthermore, technologies to implement the modules from the architecture are suggested. This proposal, as well as its validation, is framed within the scope of the SusCity project.

Nowadays, technology is such an integral part of our lives that the dependency on its benefits is growing faster than ever. With the arrival of the paradigms of smart cities and the Internet of Things, citizens are able to improve their quality of life. Given that sensors and actuators deployed in smart cities usually have limited resources, today, it is a common practice to use cloud computing to extend the scope and benefits of smart cities. Taking into consideration that communication between applications and devices is vital for a good performance of services in a smart city, it is necessary to design new architectures and mechanisms to provide reliability in communications. A key aspect that has to be addressed by the new communications approaches is the possibility to recover the network and its services in case of faults, without human intervention. In this paper, a novel architecture to improve the resilience level of the infrastructure in the Internet of Things is proposed. Moreover, technologies to implement the components from the architecture are suggested. This proposal is discussed within the scope of the SusCity project.

Quality of Service Routing is at present an active and remarkable research area, since most emerging network services require specialized Quality of Service (QoS) functionalities that cannot be provided by the current QoS-unaware routing protocols. The provisioning of QoS based network services is in general terms an extremely complex problem, and a significant part of this complexity lies in the routing layer. Indeed, the problem of QoS Routing with multiple additive constraints is known to be NP-hard. Thus, a successful and wide deployment of the most novel network services demands that we thoroughly understand the essence of QoS Routing dynamics, and also that the proposed solutions to this complex problem should be indeed feasible and affordable. This article surveys the most important open issues in terms of QoS Routing, and also briefly presents some of the most compelling proposals and ongoing research efforts done both inside and outside the E-Next Community to address some of those issues. q

Abstract. The increase in multimedia content on the Internet has created a renewed interest in quality assessment. There is however a main difference from the traditional quality assessment approaches, as now, the focus relies on the user perceived quality, opposed to the network centered approach classically proposed. In this paper we overview the most relevant challenges to perform Quality of Experience (QoE) assessment in IP networks and highlight the particular considerations necessary when compared to alternative mechanisms, already deployed, such as Quality of Service (QoS). To assist on the handling of such challenges we first discuss the different approaches to Quality of Experience assessment along with the most relevant QoE metrics, and then we discuss how they are used to provide objective results about user satisfaction.