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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.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.

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.


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and corresponding transmission cost with different . (a) ; (b) Transmission cost.
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sensors-15-12273-f009: and corresponding transmission cost with different . (a) ; (b) Transmission cost.

Mentions: In this section, we evaluate the performance of RWTQ and DWTQ by both theoretical analysis and simulation. First, in Section 5.1, we discuss how the performances of the filter-based approaches are affected by the size of the network, dynamics of sensors’ readings and decline of the whole readings’ range through a theoretical analysis based on a simple model. We first set up a simple wireless senor network with a square topology and then model the message, energy consumption, readings, physical phenomenon and the measurement error. The performance of filter-based approaches is compared with that of a representative aggregation-based approach TAG [3]. The analysis results are presented in Figure 8, Figure 9, Figure 10 and Figure 11. Through theoretical analysis, we can find that the filter-based approaches are useless in certain situations and it is essential to develop a novel top- query method. Then, in Section 5.2, Section 5.3, Section 5.4 and Section 5.5, we use the simulator ns-3 [18] (version 3.21) to evaluate the performances of RWTQ and DWTQ. We compare them to TAG, FILA and EXTOK in terms of transmission cost, query accuracy, energy cost and network lifetime. Finally, in Section 5.6, we give a concluding discussion of the simulations. Table 2 is given for users to index the parameters.


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

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

and corresponding transmission cost with different . (a) ; (b) Transmission cost.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-12273-f009: and corresponding transmission cost with different . (a) ; (b) Transmission cost.
Mentions: In this section, we evaluate the performance of RWTQ and DWTQ by both theoretical analysis and simulation. First, in Section 5.1, we discuss how the performances of the filter-based approaches are affected by the size of the network, dynamics of sensors’ readings and decline of the whole readings’ range through a theoretical analysis based on a simple model. We first set up a simple wireless senor network with a square topology and then model the message, energy consumption, readings, physical phenomenon and the measurement error. The performance of filter-based approaches is compared with that of a representative aggregation-based approach TAG [3]. The analysis results are presented in Figure 8, Figure 9, Figure 10 and Figure 11. Through theoretical analysis, we can find that the filter-based approaches are useless in certain situations and it is essential to develop a novel top- query method. Then, in Section 5.2, Section 5.3, Section 5.4 and Section 5.5, we use the simulator ns-3 [18] (version 3.21) to evaluate the performances of RWTQ and DWTQ. We compare them to TAG, FILA and EXTOK in terms of transmission cost, query accuracy, energy cost and network lifetime. Finally, in Section 5.6, we give a concluding discussion of the simulations. Table 2 is given for users to index the parameters.

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.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.

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