In this study, we considered a heterogeneous, clustered WSN, which consists of two
types of nodes (clusterheads and sensor nodes) deployed randomly over a sensing field.
We investigated two cases based on how clusterheads can reach the sink: direct and
multi-hop communication cases. Network dimensioning problems in randomly deployed
WSNs are among the most challenging ones as the attributes of these networks are
mostly non-deterministic. We focused on a number of network dimensioning problems
based on the connected coverage concept, which is the degree of coverage achieved by
only the connected devices. To evaluate connected coverage, we introduced the term
cluster size, which is the expected value of the area covered by a clusterhead together
with sensor nodes connected to it. We derived formulas for the cluster size and validated
them by computer simulations. By using the cluster size formulas, we proposed
a method to dimension a WSN for given targeted connected coverage.
Furthermore, we formulated cost optimization problems for direct and multi-hop
communication cases. These formulations utilize not only cluster size formulas but also
the well-connectivity concept. We suggested some search heuristics to solve these optimization
problems. Additionally, we justified that, in practical cases, node heterogeneity
can provide lower cost solutions. We also investigated the lifetime of WSNs and for
mulated a cost optimization problem with connected coverage and lifetime constraints.
By solving this optimization problem, one can determine the number of nodes of each
type and the initial energies of each type of node that leads to lowest cost solution while
satisfying the minimum connected coverage and minimum lifetime requirements.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12611213/index.pdf |
| Date | 01 September 2009 |
| Creators | Sevgi, Cuneyt |
| Contributors | Kocyigit, Altan |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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