Wireless Sensor Networks (WSNs) have emerged as a new monitoring and control solution for a variety of applications. Although the behavior of a WSN is characterized by the type of its application, a common element exist: faults are a normal fact, not isolated events as in traditional networks. Thus, in order to guarantee the network quality of service it is essential for the WSN to be able to detect failures and perform something akin to healing, recovering from events that might cause some of its parts to malfunction. In this work we propose and evaluate a failure detection scheme using a management architecture for WSNs, called MANNA. We take a deep look at its fault management capabilities supposing the existence of an event-driven WSN. This is a challenging and attractive kind of WSN and we show how the use of automatic management services defined by MANNA can provide self-configuration, self-diagnostic, and self-healing (some of the self-managing capabilities). We also show that the management solution promote the resources productivity without incurring a high cost to the network.

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Mobile ad hoc networks (MANETs) and peer-to-peer (P2P) applications are emerging technologies based on the same paradigm: the P2P paradigm. Motivated, respectively, by the necessity of executing applications in environments with no previous infra-structure and the demand for applications that share files or distribute processing through the Internet, MANETs and P2P applications have received some interest from research community. As a characteristic of the distributed model, which they follow, such technologies face a difficult task of routing requests in a decentralized environment. In this paper, we conducted a detailed study of a Gnutella-like application running over a MANET where three different protocols were considered. The results show that each protocol that were analyzed performed well in under some conditions and for some metrics, while had drawbacks in others.

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SUMMARYIn this work, we present a self-management service for Wireless Sensor Networks (WSNs) that automatically controls the network redundancy. Based on a density control function, this service improves the monitoring potential of the sensor nodes. Our simulation experiments show that this self-management service provides good and lasting coverage, as desired by WSNs applications.