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Sant'Ambrogio di Torino, Italy

Soares J.M.,University of Lisbon | Zhang W.,Polytechnic University of Turin | Franceschinis M.,Pervasive Radio Technologies PeRT Laboratory | Spirito M.A.,Pervasive Radio Technologies PeRT Laboratory | Rocha R.M.,University of Lisbon
2010 Future Network and Mobile Summit | Year: 2010

The use of opportunistic communications, while increasing in popularity, is still limited, due in part to some uncertainty that still exists regarding its performance in real-world conditions. This paper tries to assess the real performance of an opportunistic routing implementation in a physical setting, by comparing it with its expected performance, determined by a simplified theoretical model. For that purpose, we have deployed an experimental testbed combining static and mobile sensor nodes, and running two different applications in two different platforms in tandem. This allows us to obtain real contact traces from an unmodified application, while at the same time logging the messages transferred between participating nodes. The data collected was later analysed, mainly in what refers to the intra-contact and global communication patterns, as well as the end-to-end delay distributions for each sending node's messages. The results obtained show that the system behaviour can be predicted with high accuracy by our simple model. Copyright © 2010 The authors. Source

Khan S.U.,University of Peshawar | Lavagno L.,Polytechnic University of Turin | Pastrone C.,Pervasive Radio Technologies PeRT Laboratory | Spirito M.A.,Pervasive Radio Technologies PeRT Laboratory
International Journal of Distributed Sensor Networks | Year: 2014

In recent years, the adaptation of wireless sensor networks (WSNs) to application areas requiring mobility increased the security threats against confidentiality, integrity, and privacy of the information as well as against their connectivity. Since key management plays an important role in securing both information and connectivity, a proper authentication and key management scheme is required in mobility enabled applications where the authentication of a node with the network is a critical issue. In this paper, we present an authentication and key management scheme supporting node mobility in a heterogeneous WSN that consists of several mobile sensor nodes and a few fixed sensor nodes. We analyze our proposed solution by using the OMNET++ simulator to show that it requires less memory space and provides better connectivity and network resilience against node capture attacks compared to some existing schemes. We also propose two levels of secure authentication methods for the mobile sensor nodes for secure authentication and key establishment. © 2014 Sarmad Ullah Khan et al. Source

Soares J.M.,University of Lisbon | Franceschinis M.,Pervasive Radio Technologies PeRT Laboratory | Rocha R.M.,University of Lisbon | Rocha R.M.,Institute Telecomunicaes | And 2 more authors.
Eurasip Journal on Wireless Communications and Networking | Year: 2011

Opportunistic wireless sensor networks (WSNs) have recently been proposed as solutions for many remote monitoring problems. Many such problems, including environmental monitoring, involve large deployment scenarios with lower-than-average node density, as well as a long time scale and limited budgets. Traditional approaches designed for conventional situations, and thus not optimized for these scenarios, entail unnecessary complexity and larger costs. This paper discusses the issues related with the design and test of opportunistic architectures, and presents one possible solution - CHARON (Convergent Hybrid-replication Approach to Routing in Opportunistic Networks). Both algorithm-specific and comparative simulation results are presented, as well as real-world tests using a reference implementation. A comprehensive experimental setup was also used to seek a full characterization of the devised opportunistic approach including the derivation of a simple analytical model that is able to accurately predict the opportunistic message delivery performance in the used test bed. Copyright © 2011 Jorge M. Soares et al. Source

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