The meteoric rise and prevalent usage of wireless networking technologies for mobile
communication applications have captured the attention of media and imagination of
public in the recent decade. One such proliferation is experienced in Wireless Sensor
Networks (WSNs), where multimedia enabled elements are fused with integrated
sensors to empower tightly coupled interaction with the physical world. As a promising
alternative to antiquated wired systems and traditional WSNs in a multitude of novel application
scenarios, the newly renovated WSNs have inspired a wide range of research
among which investigation on data acquisition techniques is a fundamental one. In this
dissertation, we address the problem of data acquisition in next generation WSNs. As
wireless sensors are powered with limited energy resources while they are expected to
work in an unattended manner for a long duration, energy conservation stands as the
primal concern. Also, to enable in-situ sensing in different rate-constrained applications,
routing decisions should care about the medium access feasibility of achievable
end-to-end data rates. Driven by the fact, we first design cross-layer medium contention
aware routing schemes for rate-constrained traffic in single-channel WSNs that maximize
network lifetime. Three sufficient conditions on rate feasibility, referred to as
rate-based, degree-based, and mixed constraints, are incorporated into the routing formulations
to guarantee the practical viability of the routing solutions. Next, with the aim
to mitigate interference and hence to enhance network capacity, we extend our work
by proposing energy and cross-layer aware routing schemes for multichannel access
WSNs that account for radio, MAC contention, and network constraints. In that context,
we first derive three new sets of sufficient conditions that ensure feasibility of data
rates in multichannel access WSNs. Then, utilizing these sets, we devise three different
MAC-aware routing optimization schemes, each aiming to maximize the network
lifetime while meeting data rate requirements of end-to-end flows. Finally, we perform
extensive simulation studies to evaluate and compare the performance of the proposed
routing approaches under various network conditions. So far works are done in milieu
of WSNs with both fixed access node and sensor nodes. In the subsequent part
of the dissertation, we present the continuation of our work focusing on reliable data
acquisition in Mobile WSNs for a promising application namely free-ranging animal
tracking/monitoring. To accomplish that goal, we concentrate on providing sufficient
conditions on access-point density that limit the likelihood of buffer overflow. We first
derive sufficient access-point density conditions that ensure that the data loss rates are
statistically guaranteed to remain below a given threshold. Then, we evaluate and validate
the derived theoretical results with both synthetic and real-world data. / Graduation date: 2012
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28906 |
| Date | 12 March 2012 |
| Creators | Ehsan, Samina |
| Contributors | Hamdaoui, Bechir |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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