A Method for Continuous Exact Top-k Query in Asynchronous Wireless Sensor Networks
| Autor: | Chi-Feng Chiang, 江奇峰 |
|---|---|
| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 After running the continuous exact top-k query in asynchronous wireless sensor networks, base station will continue to get the top-k sensors and their values. Zong-Wei Liu had proposed a method for continuous exact top-k query, this method use what so called candidate for reducing the number of sensor's transmission in order to lower power comsumption and to extend network lifetime. This research improved Zong-Wei Liu's method by setting a cache with length of c, running top-(k+c) query in every base station's broadcast, and then doing the broadcast when the cache data is depleted. Besides, we use minimum value of the cache as a threshold in order to lower base station broadcast's threshold and probe value. Consequently, although some sensors' upload data frequency is increased, the broadcast frequency is decreased. Overall, sensors transmission frequency is reduced and the network lifetime is extended. We compare our method with Liu's method on ten types of topology. As a result, for k = 3, 4, 5, 7, and 10, our method could increase network lifetime by 43%. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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