Wireless sensor networks (WSNs) and Internet of Things (IoT) have been used to build several eHealth systems, which enable a physician (or caregiver) to monitor a patient (or elderly) continuously and real time, either locally or remotely, at lower cost and being less intrusive in the routine than the traditional monitoring equipment. Physical therapy aiding systems are a particular case of such systems, with specific characteristics and requirements, concerning equipment, software, and system. This work presents a system aimed at assessing joint angle and vital signs to assist physical therapists. The system is also available to hydrotherapy, which imposes packaging, sensing, and communication challenges. We discuss our design and implementation, as well as common problems with this kind of application. We also present statistical analysis of the system results based on experiments conducted and compared to a goniometer, a standard physical therapy device.

Motivated by the internets of the future, which will likely be considerably larger in size as well as highly heterogeneous and decentralized, we propose Decentralize-SDN, D-SDN, a framework that enables not only physical- but also logical distribution of the Software-Defined Networking (SDN) control plane. D-SDN accomplishes network control distribution by defining a hierarchy of controllers that can “match” an internet's organizational- and administrative structure. By delegating control between main controllers and secondary controllers, D-SDN is able to accommodate administrative decentralization and autonomy.It incorporates security as an integral part of the framework. This paper describes D-SDN and presents two use cases, namely network capacity sharing and public safety network services.

This paper proposes a novel approach to capacity sharing in hybrid networked environments, i.e., environments that consist of infrastructure-based as well as infrastructureless networks. The proposed framework is based on Software-Defined Networking (SDN) and provides flexible, efficient, and secure capacity sharing solutions in a variety of hybrid network scenarios. In this paper, we describe the challenges raised by capacity sharing in hybrid networks, describe our framework in detail and how it addresses these challenges, and discuss implementation issues. To the best of our knowledge, this is the first SDN-based capacity sharing solution that targets hybrid networks and that incorporates security as an integral part of the proposed approach.

Security is an important concern in any modern network. This also applies to Wireless Sensor Networks (WSNs), especially those used in applications that monitor sensitive information (e.g., health care applications). However, the highly constrained nature of sensors impose a difficult challenge: their reduced availability of memory, processing power and energy hinders the deployment of many modern cryptographic algorithms considered secure. For this reason, the choice of the most memory-, processing- and energy-efficient security solutions is of vital importance in WSNs. To date, several authors have developed extensive analyses comparing different encryption algorithms and key management schemes, while very little attention has been given to message authentication mechanisms. In this paper, we address this issues by identifying Authenticated Encryption with Associated Data (AEAD) schemes suitable for WSNs and by evaluating their features and performance on TelosB sensor nodes. As a result of this analysis, we identify the recommended choices depending on the characteristics of the target network.

Wireless Sensor Networks (WSNs) are a valuable technology to support countless applications in different areas. Given the WSN nodes resource constrained characteristics, designing energy-aware applications, communication protocols and security mechanisms are critical. The operating system (OS) running on the WSN node also interferes with the node overall behavior, and its energy consumption. In this paper, we develop a comparison between two different operating systems (Contiki and TinyOS) running on the same hardware platform (Crossbow TelosB). Using a set of tasks, which includes sensing, communication and security mechanisms, we evaluate their behavior in terms of energy consumption and execution time.

Security in Wireless Sensor Networks (WSNs) is highly dependent on the behavior of the base station. This happens because, if the network is left unattended, sensor nodes cannot offload data to the (secure) base station in real time and, thus, until the base station becomes available, adversaries can compromise some sensor nodes and selectively destroy data. In order to prevent such attacks, providing the so-called “data survival”, some strategies can be employed. In this paper, we discuss and analyze different data survival strategies using cryptography. To the best of our knowledge, we provide the first implementation of such techniques, using a real sensor platform for their evaluation. As a result, we show that the main costs for the data survival process are not as high as it could be expected, and that strategies based on private keys can be used even if one considers the highly resource constrained nature of sensors.