Power saving class management for energy saving in IEEE 802.16e wireless networks

Power saving is a critical issue in the IEEE 802.16e broadband wireless networks. In order to reduce the power consumption, the IEEE 802.16e provides three types of power saving classes (PSCs) for the Mobile Subscriber Stations (MSSs), where each PSC may contain one or several connections. However, how to define a PSC and assign PSCs to connections are open issues in the standard. Focusing on realtime traffics, a single MSS and base station (BS) pair, previous studies use a single PSC of type II to manage the awake and sleep of the MSS. In this paper, two power saving class management algorithms based on multiple PSCs in the IEEE 802.16e are proposed. These two schemes define PSCs for realtime connections by referring to the delay bound and packet interarrival time of connections. Simulation results demonstrate that our schemes outperform the previous single PSC approach in both energy efficiency and resource utilization.