| Summary: | 碩士 === 國立交通大學 === 工業工程與管理系所 === 104 === Lifetime extension has been the major constraint of developing wireless sensor networks (WSNs). Most of previous related works separately considered dynamics and heterogeneity of WSNs, or only considered static network scenarios, so that practical conditions are not achieved. In addition, recent works have tended to developing the technologies of energy-harvesting (EH) sensors, which can absorb natural power (e.g., solar and wind power) to extend lifetime of sensor devices. However, restricted to cost and technology problems, it is infeasible to replace all wireless sensors by EH sensors, so that an appropriate approach is to apply a hybrid WSN consisting of EH sensors and common sensors under constraints of installation cost and transmission. Therefore, this project investigates the problem of extending the lifetime of a dynamic heterogeneous WSN with EH and common sensors, in which we consider dynamic states of each sensor at different time points to determine the sleep schedule of each sensor, so that all targets to be monitored are covered, and the total network lifetime is extended. Since the case for state WSNs has been shown to be NP-complete, the concerned problem is also NP-complete. Hence, this work first models this problem mathematically, and then proposes an improved multi-population harmony search algorithm for this problem. By simulation, the network lifetime, stability, and executing time of the proposed algorithm are analyzed. Experimental results show that the proposed algorithm performs better, and indeed helps extend the total WSN lifetime.
|
|---|
