A Wireless Sensor Network (WSN) is composed of low-cost electronic devices with sensing, data storage and transmitting capabilities, powered by batteries. There are extensive studies in the field of WSN investigating different algorithms and protocols for data collection. A data collector can be static or mobile. Using a mobile data collector can extend network lifetime and can be used to collect sensor data in hardly accessible locations, partitioned networks, and delay-tolerant networks. The implementation of the mobile data collector in our study consists of combining two different platforms: the Crossbow sensor hardware and the NXT Legos. We developed an application for data collection and sensor querying support. Another important contribution is designing a semi-autonomous robot control. This hardware prototype implementation shows the benefits of using a mobile data collector in WSN. It also serves as a reference in developing future applications for mobile WSNs. / by Pedro L. Heshike. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Sensors are used to monitor and control the physical environment. A Wireless Sen- sor Network (WSN) is composed of a large number of sensor nodes that are densely deployed either inside the phenomenon or very close to it [18][5]. Sensor nodes measure various parameters of the environment and transmit data collected to one or more sinks, using hop-by-hop communication. Once a sink receives sensed data, it processes and forwards it to the users. Sensors are usually battery powered and it is hard to recharge them. It will take a limited time before they deplete their energy and become unfunctional. Optimizing energy consumption to prolong network lifetime is an important issue in wireless sensor networks. In mobile sensor networks, sensors can self-propel via springs [14], wheels [20], or they can be attached to transporters, such as robots [20] and vehicles [36]. In static sensor networks with uniform deployment (uniform density), sensors closest to the sink will die first, which will cause uneven energy consumption and limitation of network life- time. In the dissertation, the nonuniform density is studied and analyzed so that the energy consumption within the monitored area is balanced and the network lifetime is prolonged. Several mechanisms are proposed to relocate the sensors after the initial deployment to achieve the desired density while minimizing the total moving cost. Using mobile relays for data gathering is another energy efficient approach. Mobile sensors can be used as ferries, which carry data to the sink for static sensors so that expensive multi-hop communication and long distance communication are reduced. In this thesis, we propose a mobile relay based routing protocol that considers both energy efficiency and data delivery delay. It can be applied to both event-based reporting and periodical report applications. / Another mechanism used to prolong network lifetime is sensor scheduling. One of the major components that consume energy is the radio. One method to conserve energy is to put sensors to sleep mode when they are not actively participating in sensing or data relaying. This dissertation studies sensor scheduling mechanisms for composite event detection. It chooses a set of active sensors to perform sensing and data relaying, and all other sensors go to sleep to save energy. After some time, another set of active sensors is chosen. Thus sensors work alternatively to prolong network lifetime. / by Yinying Yang. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

This work describes the design and implementation of a generic architecture to provide a collective solution for power-aware routing to a wide range of problems in wireless sensor network environments. Power aware-routing is integral to the proposed solutions for different problems. These solutions try to achieve power-efficient routing specific to the problem domain. This can lead to challenging technical problems and deployment barriers when attempting to integrate the solutions. This work extracts various factors to be considered for a range of problems in wireless sensor networks and provides a generic framework for efficient power-aware routing. The architecture aims to relieve researchers from considering power management in their design. We have identified coupling between sources and sinks as the main factor for different design choices for a range of problems. We developed a core-based hierarchical routing framework for efficient power-aware routing that is used to decouple the sources from sinks. The architecture uses only local interaction for scalability and stability in a dynamic network. The architecture provides core-based query forwarding and data dissemination. It uses data aggregation and query aggregation at core nodes to reduce the amount of data to be transmitted. The architecture can be easily extended to incorporate protocols to provide QoS and security to the applications. We use network simulations to evaluate the performance of cluster formation and energy efficiency of the algorithm. Our results show that energy efficiency of the algorithm is better when the transmission range is kept to a minimum for network connectivity as compared to adjustable transmission range.