Abstract:

In a mobile broadband wireless metropolitan area network, how to reduce the energy consumption of the station battery and extend the life of the mobile network has become the research focus in the related field. For the sleep mechanism in IEEE 802.16m, the packets can be transmitted during the listening window, and the listening window can be expanded as needed. Regarding the listening window with packet transmission as a busy period, and the listening window without packet transmission together with the subsequent sleep window is seen as a vacation period, then a queueing model with multiple-vacation is built. The first vacation length is supposed to follow a PH distribution, the subsequent vacations are assumed to increase binary-exponentially. Applying the method of matrix geometric, the queueing system is analyzed in steady-state, the formulas for the energy saving ratio and the average delay of packets are given, moreover, a cost function is constructed by combining different performance measures. With simulation results, the initial phase for the first vacation length is given. Numerical results are provided to investigate the system performance and optimize the system parameter.

Key words: IEEE 802.16m, sleep mechanism, multiple-vacation, PH distribution