Performance analysis for power saving class type III of IEEE 802.16 in WiMAX

In this paper, we present an effective method to analyze the performance of the power saving class type III initiated by the base station with unsolicited MOB_SLP-RSP or DL sleep control extended subheader in a self-similar traffic. We build a batch arrival queueing model, in which the batch size is described by a random variable following a Pareto( c, α) distribution in order to capture the self-similar property in multimedia WiMAX based on the IEEE 802.16. By using the discrete-time embedded Markov chain, we can examine and analyze the power saving class type III systems for the following items: the probability generating functions of the number of data frames and batches when the busy period begins, the queueing length, the waiting time and finally the busy cycle. With the first and higher derivatives of the probability generating functions, we can give the averages and the standard deviations for the system performance using the diffusion approximation for the operation process of the system. Next, we give the formulas for the system performance such as the energy saving ratio, the switching ratio, the system utility and the response time of data frames. Moreover, we construct a cost function with the aim of determining the optimal sleep window length that minimizes the cost function. Numerical results are provided with analysis and simulation to show the average performance measures, standard deviations and a cost function with different degrees of self-similarity and different sleep window lengths.