• Coverage
• Security
• Distributed Algorithm
• Sensor Networks

This thesis addresses a Deployment Problem related to mobile Wireless Sensor Networks (WSNs), where the goal is obtaining a desired deployment of a team of sensor nodes over a known area, by using a decentralized algorithm.
Starting from their random initial positions in the region that we wish to monitor, sensors have to cover a sub-region of maximum area and, contemporarily, a desired distance between every couple of neighboring nodes has to be maintained.
This distance constraint guarantees a suitable degree of connectivity among sensors. Distance parameter can be chosen in different ways, depending on the goal we want to reach.
One possibility is to impose the distance between two neighbors in such way that they can communicate, i.e. this distance has to be smaller than the communication range of each sensor. In this manner we obtain a complete connectivity in the WSN. Also, obtaining a meshed network increases the possibility of having disjoint paths from a node to another one, enhancing the communication capability.
Another choice is to set the distance so that each point of the region monitored by a node which is not a border node, is monitored by at least one node. This allows us to obtain a complete coverage of the area over which are placed the internal nodes of the WSN.
Furthermore, the distance can be chosen so that every point of the area over which the nodes are distributed is observed by not only a node, but by a desired number of nodes, obtaining the necessary redundancy to detect a faulty node that would voluntarily or unintentionally be able to communicate wrong events.
Finally, a protocol with the goal of detecting the presence of a node that has not a correct behavior has been implemented and tested.