A Delay-aware Auto Sleep Mode Operation for Power Saving WiMAX

To support battery powered mobile broadband wireless access devices efficiently, IEEE 802.16e defines a sleep mode operation for conserving the power of mobile terminals. However, extensive research shows that frequent sleep causes serious delay. In this paper we analyze the relationship between the power consumption and the delay with a Markov chain model. Then, we present a heuristic algorithm to adapt the parameters of sleep mechanism to the network condition and the delay requirement. Extensive simulation results show that the proposed algorithm can efficiently bound the delay in the required range. Meanwhile, the proposed algorithm achieves marked gain in power consumption compared to the traditional sleep mechanism.