• Discovery Protocol
• Opportunistic Networks
• Power Management
• WSN

Wireless sensor networks (WSNs) are emerging as an effective solution for a wide range of applications, especially for environmental monitoring. In many scenarios, a moderate number of sparsely deployed nodes can be sufficient to get the required information about the sensed phenomenon. To this end, Mobile elements (MEs) can be used to get data sampled by sensor nodes, by moving through the sensing area and collecting data from static sensors. In this thesis, we propose a novel protocol for ME discovery by sensor nodes, namely Dual Beacon Protocol, i.e., 2BD, and a complete analytical model of the system, in order to assess the performance of the protocol with respect to other ME discovery protocols. Our analytical results have shown that 2BD achieves a huge energy reduction with respect to a commonly used ME discovery protocol, especially when the sensor node remains in discovery state for a very long time.