An efficient MAC-based scheme against pollution attacks in XOR network coding-enabled WBANs for remote patient monitoring systems

Wireless Body Area Networks (WBANs) play a pivotal role to remote patient monitoring which is one of the main applications of m-Health. However, WBANs comprise a subset of Wireless Sensor Networks (WSNs), and thus, they inherit the limitations of WSNs in terms of communication bandwidth, reliability and power consumption that should be addressed so that WBANs can reach their full potential. Towards this direction, XOR Network Coding (NC) is a promising solution for WBANs. Nevertheless, XOR NC is vulnerable to pollution attacks, where adversaries (i.e., compromised intermediate nodes) inject into the network corrupted packets that prevent the destination nodes from decoding correctly. This has as a result not only network resource waste but also energy waste at the intermediate nodes. In this sense, pollution attacks comprise a serious threat against WBANs (i.e., resource-constrained wireless networks), that should be addressed so that WBANs can reap the benefits of XOR NC. Therefore, in this paper, we propose an efficient Message Authentication Code (MAC)-based scheme providing resistance against pollution attacks in XOR NC-enabled WBANs for remote patient monitoring systems. Our proposed scheme makes use of a number of MACs which are appended to the end of each native packet. Our results show that the proposed MAC-based scheme is more efficient compared to other competitive schemes for securing XOR NC against pollution attacks in resource-constrained wireless networks, in terms of communication bandwidth and computational complexity

Boiclimatic urban planning outdoor spaces, bioclimatic conditions simulation using the program Envi-met in central square, Nea Smyrni

125 σ.Οι μικροκλιματικές συνθήκες γύρω από τα κτίρια, τους δρόμους και τους ελεύθερους χώρους προσδιορίζονται από τη φυσική μορφή της πόλης και είναι πλέον ανάγκη η πρόβλεψη τους για τον σωστό σχεδιασμό σε μελέτες ανάπλασης ή μελέτες νέων αστικών υπαίθριων χώρων. Σκοπός της παρούσας διπλωματικής εργασίας είναι η έρευνα για το κατά πόσο μπορούμε να προβλέψουμε το αστικό μικροκλίμα με τη χρήση υψηλής ευκρίνειας μαθηματικών μοντέλων και κατά πόσο επιδρά η αστική γεωμετρία και τα υλικά σε αυτό. Η διερεύνηση έγινε με την ανάλυση των αποτελεσμάτων της προσομοίωσης των βιοκλιματικών συνθηκών του μικροκλίματος της αστικής περιοχής της κεντρικής πλατείας Νέας Σμύρνης. Το λογισμικό που χρησιμοποιήθηκε είναι το Εnvi-met (V3.1) του οποίου γίνεται παρουσίαση και αξιολόγηση.Τhe natural form of the city determines the microclimatic conditions around buildings, streets, and unoccupied areas, therefore the prediction of these conditions is now a necessity in order to get the correct design in regeneration studies or studies for the creation of new urban out-of-doors areas. The present dissertation aims to examine the degree in which we can predict urban microclimate using high-definition mathematical models, as well as the degree in which the microclimate is affected by urban geometry and materials. The research was conducted by analyzing the results of a bioclimatic conditions simulation for microclimate in the urban area of Nea Smyrni's central square. For our work we used the Εnvi-met (V3.1) software system, which we present and evaluate in our report.Ελένη Ε. Καρτσακλ

D2D-Aware Device Caching in mmWave-Cellular Networks

In this paper, we propose a novel policy for device caching that facilitates popular content exchange through high-rate device-to-device (D2D) millimeter-wave (mmWave) communication. The D2D-aware caching policy splits the cacheable content into two content groups and distributes it randomly to the user equipment devices, with the goal to enable D2D connections. By exploiting the high bandwidth availability and directionality of mmWaves, we ensure high rates for the D2D transmissions, while mitigating the co-channel interference that limits the throughput gains of the D2D communication in the sub-6-GHz bands. Furthermore, based on a stochastic-geometry modeling of the network topology, we analytically derive the offloading gain that is achieved by the proposed policy and the distribution of the content retrieval delay considering both half- and full-duplex modes for the D2D communication. The accuracy of the proposed analytical framework is validated through Monte Carlo simulations. In addition, for a wide range of a content popularity indicator, the results show that the proposed policy achieves higher offloading and lower content-retrieval delays than existing state-of-the-art approaches. © 1983-2012 IEEE

Communication recovery with emergency aerial networks

In spite of the significant advancements in wireless connectivity, the static form of the network infrastructure cannot guarantee an uninterrupted operation of the ever-growing wireless consumer electronics in emergency situations such as natural disasters. In such occasions, employing flexible aerial nodes can tackle this issue by recovering the communication rapidly, when the need for connectivity is of utmost importance. In this paper, we study the use of aerial nodes for communication recovery after a communication breakdown. We provide an analytical model of the recovery probability that demonstrates the capabilities of such networks. In the performance evaluation, we show the effects of the altitude and the distance between the aerial nodes on the recovery probability and verify them with simulations. Moreover, we introduce our testbed and preliminary experimental work that shows promising results for aerial networks. Finally, we discuss useful insights for the network design and present some open issues that exist in this field. © 2017 IEEE

Machine–to–Machine Communications for E-Health Applications

International audienceThe emerging technology of machine-to-machine (M2M) communications is bringing a paradigm shift in healthcare delivery. A broad range of e-health applications can be conceived, with considerable benefits for both patients and healthcare providers. Many technological challenges have to be met, however, to ensure the widespread adoption of e-health solutions in the future. In this context, we aim to provide a comprehensive overview on M2M systems for e-health applications from a wireless communication perspective. We provide an overview of the candidate wireless technologies that are suitable for different parts of the M2M system architecture and then show how these technologies are seamlessly integrated to provide an end-to-end e-health solution. In particular, we discuss end-to-end solution designs and test bed implementations, we present the key security and privacy challenges associated with the sensitive nature of medical data, and we summarize the most recent research projects dedicated to e-health applications

Cooperative Compressed Sensing Schemes for Telemonitoring of Vital Signals in WBANs

International audienceWireless Body Area Networks (WBANs) are composed of various sensors that either monitor and transmit real time vital signals or act as relays that forward the received data packets to a nearby Body Node Coordinator (BNC). The design of an accurate and energy efficient wireless telemonitoring system can be achieved by: i) minimizing the amount of data that should be transmitted for an accurate reconstruction at the BNC, and ii) increasing the robustness of the telemonitoring system to link failures due to the nature of wireless medium. To this end, we present a novel Compressed Sensing (CS) based telemonitoring scheme, called Cooperative Compressed Sensing (CCS), that exploits the benefits of Random Linear Network Coding (RLNC) along with key characteristics of the transmitted biosignals in order to achieve an energy efficient signal reconstruction at the BNC. Simulation studies, carried out with real electrocardiographic (ECG) data, show the benefits of: i) employing RLNC, compared to the case where relays simply store and forward the original data packets, and ii) applying the proposed CCS scheme, compared to traditional CS recovery approaches