Cintia B. Margi

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In this work we characterize the energy consumption of a visual sensor network testbed. Each node in the testbed consists of a "single-board computer", namely Crossbow's Stargate, equipped with a wireless network card and a Webcam. We assess energy consumption of activities representative of the target application (e.g., perimeter surveillance) using a(More)
This paper presents an analytical model to predict energy consumption in saturated IEEE 802.11 single-hop ad hoc networks under ideal channel conditions. The model we introduce takes into account the different operational modes of the IEEE 802.11 DCF MAC, and is validated against packet-level simulations. In contrast to previous works that attempted to(More)
Wireless Sensor Networks (WSNs) have a vast field of applications, including deployment in hostile environments. Thus, the adoption of security mechanisms is fundamental. However, the extremely constrained nature of sensors and the potentially dynamic behavior of WSNs hinder the use of key management mechanisms commonly applied in modern networks. For this(More)
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(More)
In this paper, we describe our work on instrumenting network simulators to enable them to adequately and accurately account for the energy consumed by ad hoc network protocols' communication-related tasks. This is accomplished by explicitly accounting for low-power radio modes and considering the different energy costs associated with each possible radio(More)
Privacy is a key concern in Location Based Applications (LBAs), especially due to their intensive use resource constrained devices in which general purpose ciphers are di cult to deploy. In this paper, we address this issue by specifying a new, faster key-schedule algorithm for the Curupira block cipher. This special-purpose cipher follows the Wide Trail(More)
In this paper, we discuss User Centric Networks (UCNs) as a way of, if not completely solving, considerably mitigating the problem of sharing limited network capacity and resources efficiently and fairly. UCNs are self-organizing networks where the end-user plays an active role in delivering networking functions such as providing Internet access to other(More)
The deployment of security solutions in Wireless Sensor Networks (WSNs) is considered a challenge due to the highly constrained devices involved in these applications. However, due the need for security services such as confidentiality, integrity and authenticity in a large number of important scenarios, such mechanisms are made necessary. In this(More)