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Random and directed walk-based top-(k) queries in wireless sensor networks.

Fu JS, Liu Y - Sensors (Basel) (2015)

Bottom Line: A strategy of choosing the "right" way in DWTQ is carefully designed for the token(s) to arrive at the high-value regions as soon as possible.When designing the walking strategy for DWTQ, the spatial correlations of the readings are also considered.Theoretical analysis and simulation results indicate that RWTQ and DWTQ both are very robust against these parameters discussed previously.

View Article: PubMed Central - PubMed

Affiliation: School of Electronic and Information Engineering, Key Laboratory of Communication and Information Systems, Beijing Municipal Commission of Education, Beijing Jiaotong University, Beijing 100044, China. 14111005@bjtu.edu.cn.

ABSTRACT
In wireless sensor networks, filter-based top-  query approaches are the state-of-the-art solutions and have been extensively researched in the literature, however, they are very sensitive to the network parameters, including the size of the network, dynamics of the sensors' readings and declines in the overall range of all the readings. In this work, a random walk-based top-  query approach called RWTQ and a directed walk-based top-  query approach called DWTQ are proposed. At the beginning of a top-  query, one or several tokens are sent to the specific node(s) in the network by the base station. Then, each token walks in the network independently to record and process the readings in a random or directed way. A strategy of choosing the "right" way in DWTQ is carefully designed for the token(s) to arrive at the high-value regions as soon as possible. When designing the walking strategy for DWTQ, the spatial correlations of the readings are also considered. Theoretical analysis and simulation results indicate that RWTQ and DWTQ both are very robust against these parameters discussed previously. In addition, DWTQ outperforms TAG, FILA and EXTOK in transmission cost, energy consumption and network lifetime.

No MeSH data available.


Related in: MedlinePlus

An example of the readings in a query round.
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sensors-15-12273-f013: An example of the readings in a query round.

Mentions: An example of the readings for a round of query is shown in Figure 13. There are five extreme values in the overall network and the spatial correlation is also presented. In our simulation, each sensor node has ten readings in chronological order and each reading corresponding to one query round. The ten readings fluctuate as shown in Figure 14, which is similar to a period of the readings shown in Figure 12 to some extent. Note that the ten rounds rather than one round of top- query comprise an experiment.


Random and directed walk-based top-(k) queries in wireless sensor networks.

Fu JS, Liu Y - Sensors (Basel) (2015)

An example of the readings in a query round.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507629&req=5

sensors-15-12273-f013: An example of the readings in a query round.
Mentions: An example of the readings for a round of query is shown in Figure 13. There are five extreme values in the overall network and the spatial correlation is also presented. In our simulation, each sensor node has ten readings in chronological order and each reading corresponding to one query round. The ten readings fluctuate as shown in Figure 14, which is similar to a period of the readings shown in Figure 12 to some extent. Note that the ten rounds rather than one round of top- query comprise an experiment.

Bottom Line: A strategy of choosing the "right" way in DWTQ is carefully designed for the token(s) to arrive at the high-value regions as soon as possible.When designing the walking strategy for DWTQ, the spatial correlations of the readings are also considered.Theoretical analysis and simulation results indicate that RWTQ and DWTQ both are very robust against these parameters discussed previously.

View Article: PubMed Central - PubMed

Affiliation: School of Electronic and Information Engineering, Key Laboratory of Communication and Information Systems, Beijing Municipal Commission of Education, Beijing Jiaotong University, Beijing 100044, China. 14111005@bjtu.edu.cn.

ABSTRACT
In wireless sensor networks, filter-based top-  query approaches are the state-of-the-art solutions and have been extensively researched in the literature, however, they are very sensitive to the network parameters, including the size of the network, dynamics of the sensors' readings and declines in the overall range of all the readings. In this work, a random walk-based top-  query approach called RWTQ and a directed walk-based top-  query approach called DWTQ are proposed. At the beginning of a top-  query, one or several tokens are sent to the specific node(s) in the network by the base station. Then, each token walks in the network independently to record and process the readings in a random or directed way. A strategy of choosing the "right" way in DWTQ is carefully designed for the token(s) to arrive at the high-value regions as soon as possible. When designing the walking strategy for DWTQ, the spatial correlations of the readings are also considered. Theoretical analysis and simulation results indicate that RWTQ and DWTQ both are very robust against these parameters discussed previously. In addition, DWTQ outperforms TAG, FILA and EXTOK in transmission cost, energy consumption and network lifetime.

No MeSH data available.


Related in: MedlinePlus