Dynamic Power Saving Mechanism for 3G UMTS System

摘要

This paper investigates the power saving mechanism of Universal Mobile Telecommunications System (UMTS). UMTS discontinuous reception (DRX) is exercised between the network and a mobile station (MS) to save the power of the MS. The DRX mechanism is controlled by two parameters: the inactivity timer threshold t_I and the DRX cycle t_D. Analytic analysis and simulation model are proposed to study the optimal t_I and t_D selections that maximize the MS power saving under the given mean packet waiting time constraint. We also devise an adaptive algorithm called dynamic DRX (DDRX). This algorithm dynamically adjusts the t_I and t_D values to enhance the performance of UMTS DRX. Our study quantitatively shows how to select the best inactivity timer and DRX cycle values for various traffic patterns. We also show that DDRX nicely captures the user traffic patterns, and always adjusts the t_I and t_D close to the optimal values.