Performance Evaluation For The Power Saving Class Of Type Iii In Ieee 802.16e Based On "switching Procedure"

IEEE 802.16e standard with the characteristic of high bandwidth and high mobility is becoming the focuse of the broadband wireless access system. How to save the energy and extend the life time of the battery powered mobile devices during the motion process is increasingly concerned. In this paper, taking into account the"switching procedure"from the sleep mode to the awake mode, we study the performance of the power saving class of typeⅢ, which is mainly used for multicast connections and management operations.Firstly, according to the work principle of the power saving class of typeⅢ, considering the"switching procedure"from the sleep mode to the awake mode, and regarding the"switching procedure"as a setup period. The time period of transmitting data frames is abstracted as a busy period, the sleep-delay period is seen as a vacation-delay period, the sleep mode is abstracted as vacation period, a multiple vacation queueing model with a setup and vacation-delay is built.Secondly, for memoryless property of data frame arrivals initiated by users, assuming the arrival of data frames follow a geometric distribution, we build a multiple vacation Geom/G/1 queueing model with a setup and vacation-delay. In order to capthure the bursty of data frames, a batch arrival scheme is introduced and the batch size is assumed to be Pareto distributed, a multiple vacation Geomξ/G/1 queueing model with a setup and vacation-delay is built. Taking into account the correlated property of network traffics, the data frames arrival process is extended to a D-BMAP (Discrete-Time Batch Markovian Process), we build a multiple vacation D-BMAP/G/1 queueing model with a setup and vacation-delay.Thirdly, for the multiple vacation queueing model of Geom/G/1 and Geomξ/G/1 with a setup and vacation-delay, by employing the embedded Markov chain method and the boundary state variable theory, we give the solutions of the power saving class of typeⅢin steady state. For the multiple vacation queueing model of D-BMAP/G/1 with a setup and vacation-delay, applying the factorization principles with generalized vacations, we obtain the matrix generating function for the number of packets at an arbitrary epoch during the idle period, and give the related solution in steady state.Finally, the performance measure system is built for the power saving class of typeⅢ, the formulas of the system measures are presented based on the steady-state solution. The dependency relationships of system performance measures on the"switching procedure"are discussed by numerical examples and simulation experiments. Taking into account the system measures, such as the power saving ratio and the packet average response time, we construct a cost function to give the optimal time length of the sleep-delay timer.