A. Loureiro - Academia.edu (original) (raw)
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Papers by A. Loureiro
Challenges in Ad Hoc …, 2006
Fault tolerance is an essential requirement in the design of protocols and applications for Wirel... more Fault tolerance is an essential requirement in the design of protocols and applications for Wireless Sensor Networks (WSNs) since communication and hardware failures are frequent. In this paper we studied the resilience of routing protocols for continuous data dissemination WSNs in face of faults. The main causes of silent failure are presented, including some security attacks. Those failures are classified according to extension and persistence, and such classification is used to evaluate routing protocols for continuous data dissemination networks. Results show that failures under a large region of the network are the most damaging. The paper also shows how routing protocols may save energy by temporarily turning off disconnected nodes. * In sabbatical period at universities of Evry and UPMC/Paris6/LIP6, France.
How long are the phone calls of mobile users? What are the chances of a call to end, given its cu... more How long are the phone calls of mobile users? What are the chances of a call to end, given its current duration? Here we answer these questions by studying the call duration distributions (CDDs) of individual users in large mobile networks. We analyzed a large, real network of 3.1 million users and more than one billion phone call records from a private mobile phone company of a large city, spanning 0.1T B. Our first contribution is the TLAC distribution to fit the CDD of each user; TLAC is the truncated version of so-called log-logistic distribution, a skewed, power-law-like distribution. We show that the TLAC is an excellent fit for the overwhelming majority of our users (more than 96% of them), much better than exponential or lognormal. Our second contribution is the MetaDist to model the collective behavior of the users given their CDDs. We show that the MetaDist distribution accurately and succinctly describes the calls duration behavior of users in large mobile networks. All of our methods are fast, and scale linearly with the number of customers.
Ad Hoc Networks, 2005
Abstract. The key challenge in the design of wireless sensor networks is maximizing their lifetim... more Abstract. The key challenge in the design of wireless sensor networks is maximizing their lifetime. The information about the amount of available energy in each part of the network is called the energy map and can be useful to increase the lifetime of the network. In this paper, we ...
Challenges in Ad Hoc …, 2006
Fault tolerance is an essential requirement in the design of protocols and applications for Wirel... more Fault tolerance is an essential requirement in the design of protocols and applications for Wireless Sensor Networks (WSNs) since communication and hardware failures are frequent. In this paper we studied the resilience of routing protocols for continuous data dissemination WSNs in face of faults. The main causes of silent failure are presented, including some security attacks. Those failures are classified according to extension and persistence, and such classification is used to evaluate routing protocols for continuous data dissemination networks. Results show that failures under a large region of the network are the most damaging. The paper also shows how routing protocols may save energy by temporarily turning off disconnected nodes. * In sabbatical period at universities of Evry and UPMC/Paris6/LIP6, France.
How long are the phone calls of mobile users? What are the chances of a call to end, given its cu... more How long are the phone calls of mobile users? What are the chances of a call to end, given its current duration? Here we answer these questions by studying the call duration distributions (CDDs) of individual users in large mobile networks. We analyzed a large, real network of 3.1 million users and more than one billion phone call records from a private mobile phone company of a large city, spanning 0.1T B. Our first contribution is the TLAC distribution to fit the CDD of each user; TLAC is the truncated version of so-called log-logistic distribution, a skewed, power-law-like distribution. We show that the TLAC is an excellent fit for the overwhelming majority of our users (more than 96% of them), much better than exponential or lognormal. Our second contribution is the MetaDist to model the collective behavior of the users given their CDDs. We show that the MetaDist distribution accurately and succinctly describes the calls duration behavior of users in large mobile networks. All of our methods are fast, and scale linearly with the number of customers.
Ad Hoc Networks, 2005
Abstract. The key challenge in the design of wireless sensor networks is maximizing their lifetim... more Abstract. The key challenge in the design of wireless sensor networks is maximizing their lifetime. The information about the amount of available energy in each part of the network is called the energy map and can be useful to increase the lifetime of the network. In this paper, we ...