J. Sens. Actuator Netw.2016, 5(2), 10; doi:10.3390/jsan5020010 - published 5 May 2016 Show/Hide Abstract
Abstract: We focus on personal data generated by the sensors and through the everyday usage of smart devices and take advantage of these data to build a non-invasive contextual suggestion system for tourism. The system, which we call Pythia, exploits the computational capabilities of modern smart devices to offer high quality personalized POI (point of interest) recommendations. To protect user privacy, we apply a privacy by design approach within all of the steps of creating Pythia. The outcome is a system that comprises important architectural and operational innovations. The system is designed to process sensitive personal data, such as location traces, browsing history and web searches (query logs), to automatically infer user preferences and build corresponding POI-based user profiles. These profiles are then used by a contextual suggestion engine to anticipate user choices and make POI recommendations for tourists. Privacy leaks are minimized by implementing an important part of the system functionality at the user side, either as a mobile app or as a client-side web application, and by taking additional precautions, like data generalization, wherever necessary. As a proof of concept, we present a prototype that implements the aforementioned mechanisms on the Android platform accompanied with certain web applications. Even though the current prototype focuses only on location data, the results from the evaluation of the contextual suggestion algorithms and the user experience feedback from volunteers who used the prototype are very positive.
J. Sens. Actuator Netw.2016, 5(2), 9; doi:10.3390/jsan5020009 - published 4 May 2016 Show/Hide Abstract
Abstract: A Neighbourhood Area Network is a functional component of the Smart Grid that interconnects the end user domain with the Energy Services Provider (ESP) domain. It forms the “edge” of the provider network, interconnecting homes instrumented with Smart Meters (SM) with the ESP. The SM is a dual interface, wireless communication device through which information is transacted across the user (a home) and ESP domains. The security risk to the ESP increases since the components within the home, interconnected to the ESP via the SM, are not managed by the ESP. Secure operation of the SM is a necessary requirement. The SM should be resilient to attacks, which might be targeted either directly or via the network in the home. This paper presents and discusses a security scheme for groups of SMs in a Neighbourhood Area Network that enable entire groups to authenticate themselves, rather than one at a time. The results show that a significant improvement in terms of resilience against node capture attacks, replay attacks, confidentiality, authentication for groups of SMs in a NAN that enable entire groups to authenticate themselves, rather than one at a time.
J. Sens. Actuator Netw.2016, 5(2), 8; doi:10.3390/jsan5020008 - published 22 April 2016 Show/Hide Abstract
Abstract: Most existing dissemination schemes in Mobile Social Networks (MSNs) only consider the data dissemination. However, there are two types of messages: data and the control message (i.e., acknowledgment) in MSNs, and receiving acknowledgment is very important in many applications (e.g., the mobile trade and the incentive mechanism). In order to maximize the desired message delivery ratio, we have to identify the priority of each message in the network during the limited contact opportunity. Therefore, we propose a generic priority-based compare-split routing scheme, which proves to be the optimal buffer exchange strategy. During each contact opportunity, relays compare their forwarding abilities to different destinations based on two types of criteria: the contact probability and the social status. Ideally, each relay keeps the messages whose destinations meet the current relay frequently. Then, an adaptive priority-based exchange scheme, which considers the priority within each type of messages and the relative priority between two types of messages, is proposed to exchange the most benefit messages. The effectiveness of our scheme is verified through extensive simulations in synthetic and real traces.
J. Sens. Actuator Netw.2016, 5(2), 7; doi:10.3390/jsan5020007 - published 2 April 2016 Show/Hide Abstract
Abstract: Smart devices and cyber-physical systems, which are interconnected to IT systems and services, form the basis for the arising Internet of Everything, opening up new economic opportunities for its participants and users beyond its technological aspects and challenges. While today’s e-business scenarios are mostly dominated by a few centralized online platforms, future business models, which will be feasible for the Internet of Everything, need to address special requirements. Such business models, e.g., leveraging the possibilities of smart cities, need to cope with arbitrary combinations of products and services orchestrated into complex products in a highly distributed and dynamic environment. Furthermore, these arbitrary combinations are influenced by real-time context information derived from sensor networks or IT systems, as well as the users’ requirements and preferences. The complexity of finding the optimal product/service combination overstrains users and leads to decisions according to the principle of adverse selection (i.e., choosing good enough instead of optimal). Such e-business models require an appropriate underlying value generation architecture that supports users in this process. In this paper, we develop a business model that addresses these problems. In addition, we present the Distributed Market Spaces (DMS) software-system architecture as a possible implementation, which enables the aforementioned decentralized and context-centric e-business scenario and leverages the commercial possibilities of smart cities.
J. Sens. Actuator Netw.2016, 5(2), 6; doi:10.3390/jsan5020006 - published 29 March 2016 Show/Hide Abstract
Abstract: In this paper, we propose a reference architecture for Delay-Tolerant Networking (DTN) routing protocols and a thorough quantitative evaluation of many protocols proposed in the literature. We categorize DTN protocols according to their use of the three techniques that are the key elements of our reference architecture: queue management, forwarding and replication. Queue management orders and manages the messages in the node’s buffer; forwarding selects the messages to be delivered when there is a contact; and finally, replication bounds the number of replicas in the network. Contrary to most previous papers, where either only qualitative comparisons have been presented or only a single category of protocols has been analyzed, in our work, we discuss the results of our experimental activity on many of the DTN protocols in the literature. Our results, which have been obtained both using synthetic and real mobility traces, show that an effective combination of the proposed techniques can significantly improve the performance of the protocols in terms of delivery ratio, overhead and delay.
J. Sens. Actuator Netw.2016, 5(1), 5; doi:10.3390/jsan5010005 - published 3 March 2016 Show/Hide Abstract
Abstract: Over the last years, we have witnessed increasing interconnection between the physical and digital world. The so called Internet of Things (IoT) is becoming more and more a reality in application domains like manufacturing, mobile computing, transportation, and many others. However, despite promising huge potential, the application domain of smart homes is still at its infancy and lags behind other fields of IoT. A deeper understanding of this type of techno-human system is required to make this vision a reality. In this paper, we report findings from a three year pilot that sheds light on the challenges of leveraging IoT technology in the home environment. In particular, we provide details on data quality issues in real-world deployments. That is, we analyze application level data for errors in measurements as well as issues in the end-to-end communication. Understanding what data errors to expect is crucial for understanding the smart building domain and paramount for building successful applications. With our work, we provide insights in a domain of IoT that has tremendous growth potential and help researchers as well as practitioners to better account for the data characteristics of smart homes.