| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 90 === Abstract
Next-generation wireless networks are to accommodate more users accessing a wide array of information with portable battery-powered devices. Thus, minimizing the average power consumption at individual node becomes especially important. This thesis considers three uplink channel setup schemes to reduce power consumption of individual node for wireless sensor network applications in cdma2000. The backlog counter threshold scheme transits to active state when the number of packets in transmission queue exceeds the counter threshold value. The vacation timer threshold scheme transits to active state when vacation timer expires. The counter-timer hybrid scheme transits to active state either when the number of packets in queue exceeds the threshold value or when time-out occurs. All the three set-up schemes are under consideration of release scheme used to go back to inactive state when release timer expires.
The objective of our study is to evaluate the performances of the three power saving schemes using simple two-state (active state and inactive state) Markov chain model with accurately improved non-exponential distributed transition time in wireless data device for different needs of applications. Under these models, we take insights of threshold selection for reducing power consumption while satisfying the QoS requirements in terms of packet blocking probability and the mean packet delay in system. Furthermore, the performance evaluation of the tradeoffs among channel connection rate, mean packet delay and packet blocking probability, and the tradeoffs between resource (bandwidth) cost and channel connection rate are revealed.
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