Recently there has been an increased interest in the development of wireless sensor networks (WSNs), which consist of a large number of tiny sensor nodes with wireless communication ability. With dfferent sensing components and limited computational capability from onboard microprocessors, sensor nodes are able to gather different local sensing information and process them. Unlike WSNs which are composed of stationary sensors, mobile sensor networks (MSNs) have a new feature of sensor mobility, and are expected to be applied in a variety of applications such as battlefield surveillance, hostile environment monitoring, and wild animal tracking. This dissertation mainly focuses on the challenges and research works of information collection, intrusion detection and tracking in MSNs. It sho...[ Read more ]

Recently there has been an increased interest in the development of wireless sensor networks (WSNs), which consist of a large number of tiny sensor nodes with wireless communication ability. With dfferent sensing components and limited computational capability from onboard microprocessors, sensor nodes are able to gather different local sensing information and process them. Unlike WSNs which are composed of stationary sensors, mobile sensor networks (MSNs) have a new feature of sensor mobility, and are expected to be applied in a variety of applications such as battlefield surveillance, hostile environment monitoring, and wild animal tracking. This dissertation mainly focuses on the challenges and research works of information collection, intrusion detection and tracking in MSNs. It shows that sensor mobility brings a lot of challenges in MSNs, but at the same time, it also provides opportunities that can be explored for performance enhancement. In practice, sensor network systems are highly application driven and their applicability are closely related to different application environments.

We first formulate and study the delay-constrained information coverage problem in both single hop case and relay assisted case. In single hop case, our formulation takes advantage of the sensor mobility for sensing information collection, which takes place when a sensor moves into the proximity of stationary sink nodes. While in relay assisted case, by taking full advantage of sensor mobility and rendezvous during senor node encounter, messages can be delivered to a sink node either directly or through relays by other sensor nodes. Motivated by real application needs, we propose an optimal placement of sink nodes, and a practical message relay and replacement algorithm for maximizing the sensing information collection.

Prior works in static sensor environments show that constructing sensor barriers with random sensor deployment can be effective for intrusion detection. In our second application, we study the intrusion detection problem in MSNs, where it is believed that mobile sensors can improve the barrier coverage. Specifically, we focus on providing the k-barrier coverage against moving intruders. The inherent relationship between the barrier coverage performance and a set of crucial system parameters including sensor density, sensing range, sensor and intruder mobility is derived. We show that the coverage performance can be improved by an order of magnitude with the same number of sensors when compared with that of the static sensor environment.

Finally, we investigate the problem of tracking moving targets in MSNs, in which spatial and temporal resolutions for localizing a target's trajectory are two important performance metrics. Spatial resolution refers to how accurate a target's position can be measured by sensors, while the temporal resolution refers to how frequently a target's position can be measured. We derive the minimum number of mobile sensors that are required to maintain the resolutions for target tracking in an MSN, and demonstrate that sensor mobility can be exploited to improve both spatial and temporal resolutions.