Identification and ranking of relevant criteria for the selection of Software as a Service

Software as a Service (SaaS) is a model for the provision of application software that allows them to be seen as a service rather than a product. A main challenge for organizations is to understand which applications in their portfolio are more appropriate to deploy in this way. This paper proposes an approach based on the Delphi method to identify and rank the relevant criteria for the selection of applications. The results show that the Delphi method is a flexible tool that allows the expansion of knowledge, by identifying relevant criteria to the problem not foreseen by the researcher, and by providing a ranking of importance of those criteria.info:eu-repo/semantics/acceptedVersio

Non-invasive monitoring with ballistocardiographic sensors for sleep management

Sleep has an important impact on people's daily lives. A successful methodology for monitoring sleep is Polysomnography (PSG). This is an accurate and reliable approach but, unfortunately, very invasive. PSG uses expensive sensors that must be positioned by experts, what, in practice, makes its adoption only viable in hospital setups. Therefore, there is a demand for better non-invasive alternatives, such as Ballistocardiography (BCG). BCG uses cheaper sensors, easy to install and ideal for domestic use. This allows its integration in solutions that manage sleep, using mobile apps not only for presenting valuable information to users but may also for acting on the environment, through actuators, such as sound. This work uses this principle to help users to wake up smoothly. Sleep monitoring is performed with Murata SCA11H BCG external sensors. Low-pass filters have been implemented, using a sliding exponential average, for all metrics. The Random Forest algorithm was then selected for sleep phase classification, that presented the best performance when using the Weka exploration tool for learning methods. With the implemented model, it has been proved that four sleep phases are predicted. It was then possible to define a strategy for avoiding waking up alarms to be fired during deep sleep. It consists on the analysis 15 minutes prior to the alarm and, when deep sleep is detected, a relaxing sound is played. This work demonstrated that non-invasive sleep monitoring can be used to actuate on, and improve, the user environment, in a home setup with cheap sensors.info:eu-repo/semantics/acceptedVersio

Peer-to-peer collaboration in content delivery networks

A low-cost collaboration architecture for web content distribution, that aims to improve all stakeholder's interests, is presented. A peer-to-peer (P2P) contribution among the end users layer is suggested, in order to increase download rates and reduce server traffic and resource usage. In addition, the Internet Service Providers (ISPs) concerns are also considered, with an ISP-aware connection strategy in the P2P protocol. Collaboration among publisher's web server resources is also proposed, in order to improve the CDN architecture performance. All the elements of this architecture have been developed and have been successfully tested in 5 different scenarios, within the PlanetLab large-scale overlay network testbed. Results show that download speed increases after implementing P2P collaboration on a content delivery scenario, with a strong reduction of data transferred via HTTP servers. The ISP-aware approach reduces inter-ISP traffic, with an increase of download speeds. This implementation is fairer as the content popularity grows because end-users extreme download rates tend to approach to the average.info:eu-repo/semantics/acceptedVersio

A media independent information service integration architecture for media independent handover

A present challenge in wireless networks is to provide mobility, regardless of the access technology in use, with guaranteed continuity of the service and transparency for the users. One approach to these seamless handovers is to prepare network access in advance, such as pre-authentication, before the mobile device actually physically connects to the desired network. This process requires that the mobile device can discover the parameters of the networks in their geographical area prior to connect to the candidate network. To address these issues, in this paper we propose an integration architecture for a Media Independent Information Service, where several networks elements collaborate in the discovery of information network, and mobile devices collect the desired neighboring network information with a query-response mechanism in two steps. A prototype has been implemented with of the shelf hardware, and several tests have been conducted. Results are better than the ones available in the literature, and network selection is performed in a short period of time.info:eu-repo/semantics/acceptedVersio

Integration of mobile devices in home automation with use of machine learning for object recognition

The number of smart homes is increasingly expanding, with even more connected devices and available control options. Mobile devices have unfortunately been up to now generally regarded as mere remote controls in these environments. This paper addresses this shortcoming, by presenting a novel integration architecture and prototype where the potential of mobile devices sensors can be better explored in home automation platforms, in particular by detecting objects in the information collected by their cameras that subsequently allow for users to interact with them in an intuitive way. The detection is performed at the mobile side, using a lightweight machine learning solution. The obtained accuracy and processing time are comparable to that obtained at server side. But the advantage here is that the interactive experience of users can be dramatically improved, with the absence of round-trip time required if server processing would be used.info:eu-repo/semantics/publishedVersio

Towards a software defined multi-domain architecture for the internet of things

The emerging communication networks tend to aggregate heterogeneous networking infrastructures as well as data flows with very distinct requisites. This implies that the complete satisfaction of Quality of Service (QoS) metrics is very difficult to achieve, using the legacy management solutions. Alternatively, the Software Defined Networking (SDN) paradigm offers a logical centralized management of the necessary network resources for data flows, namely the ones originated in sensor devices. Therefore, this work investigates a solution that meets the QoS requirements of traffic from remote Internet of Thing (IoT) devices. To achieve this goal, we have designed a SDN-based solution that manages a network topology formed by several domains. We assume each network domain is controlled by its own SDN controller. In addition, our solution assumes that the several SDN controllers need to be orchestrated among them to maximize the management efficiency of the available end-to-end network resources. This orchestration is done via an SDN transit domain ruled by the ONOS SDN-IP application. We have emulated network topologies with IoT devices to evaluate the proposed solution in terms of its functionality, robustness against network failures, and QoS support. Analyzing the obtained results, our solution can support a cross-controller SDN domain communication. It is also capable of reacting automatically to topology failures. In addition, it can prioritize the traffic within the network infrastructure, providing to the end users strong guarantees on the desired quality for the exchange of data associated to the applications they aim to use.info:eu-repo/semantics/publishedVersio

A brokerage system for enhancing wireless access

This paper contributes to the management of a network infrastructure formed by distinct wireless access technologies, which are administered by several cooperating mobile operators. These wireless technologies may cover a public area, which at specific times of the day are overwhelmed by a large number of users. A new management solution is proposed that controls the heterogeneous network infrastructure in a distributed way, using policies and metrics, and ensuring a Quality of Service (QoS) level associated with each terminal connection. The QoS level is supported through a novel, vertical and dynamic aggregation of performance information about the wireless access, originated at distinct technologies. A closed innovative control loop among a flexible brokerage service in the network, and agents at the mobile terminals, counteracts any abnormal data load. This allows the terminals to make well-informed decisions about their connections to improve on the QoS offered to the application layer. In this way, depending on the management policies of the brokerage service and the quality metrics, wireless access technologies that by default only offer a best-effort connection service can be enhanced in a very straightforward way. The obtained results highlight the advantages for using this new distributed solution to manage the heterogeneous network infrastructure in several distinct usage scenarios.info:eu-repo/semantics/acceptedVersio

Elastic provisioning of network and computing resources at the edge for IoT services

The fast growth of Internet-connected embedded devices demands new system capabilities at the network edge, such as provisioning local data services on both limited network and computational resources. The current contribution addresses the previous problem by enhancing the usage of scarce edge resources. It designs, deploys, and tests a new solution that incorporates the positive functional advantages offered by software-defined networking (SDN), network function virtual-ization (NFV), and fog computing (FC). Our proposal autonomously activates or deactivates embedded virtualized resources, in response to clients’ requests for edge services. Complementing existing literature, the obtained results from extensive tests on our programmable proposal show the superior performance of the proposed elastic edge resource provisioning algorithm, which also assumes a SDN controller with proactive OpenFlow behavior. According to our results, the maximum flow rate for the proactive controller is 15% higher; the maximum delay is 83% smaller; and the loss is 20% smaller compared to when the non-proactive controller is in operation. This improvement in flow quality is complemented by a reduction in control channel workload. The controller also records the time duration of each edge service session, which can enable the ac-counting of used resources per session.info:eu-repo/semantics/publishedVersio

Game theory for cooperation in multi-access edge computing

Cooperative strategies amongst network players can improve network performance and spectrum utilization in future networking environments. Game Theory is very suitable for these emerging scenarios, since it models high-complex interactions among distributed decision makers. It also finds the more convenient management policies for the diverse players (e.g., content providers, cloud providers, edge providers, brokers, network providers, or users). These management policies optimize the performance of the overall network infrastructure with a fair utilization of their resources. This chapter discusses relevant theoretical models that enable cooperation amongst the players in distinct ways through, namely, pricing or reputation. In addition, the authors highlight open problems, such as the lack of proper models for dynamic and incomplete information scenarios. These upcoming scenarios are associated to computing and storage at the network edge, as well as, the deployment of large-scale IoT systems. The chapter finalizes by discussing a business model for future networks.info:eu-repo/semantics/acceptedVersio

Crowding detection combining trace elements from heterogeneous wireless technologies

Non-invasive crowding detection in quasi-real-time is required for a number of use cases, such as for mitigating tourism overcrowding. The present goal is a low-cost crowding detection technique combining personal trace elements obtained from heterogeneous wireless technologies (4G, 3G, GSM, Wi- Fi and Bluetooth) supported by mobile devices carried by most people. This work proposes detection nodes containing Raspberry-Pi boards equipped with several off-the-shelf Software Defined Radio (SDR) dongles. Those nodes perform spectrum analysis on the bands corresponding to the aforementioned wireless technologies, based on several open source software components. The outcome of this edge computing, performed in each node, is integrated in a cloud server using a Long Range Wide Area Network (LoRaWAN), a recent technology developed for IoT applications. Our preliminary results show that is possible to determine the number of mobile devices in the vicinity of each node, by combining information from several wireless technologies, each with its own detection range and precision.info:eu-repo/semantics/acceptedVersio