Article history:

30 March 2011 Keywords: Power management is a critical issue in IEEE 802.16 wireless networks. In the standard, a for non-real-time variable-rate (NRT-VR) and Best-Effort (BE) connections. For type II, both listening and sleep win-dows are of fixed sizes. Such a PSC is deactivated only when asked. This type is suitable for Unsolicited Grant Service Intensive works have been devoted to the power saving issues of IEEE 802.11 networks [2–4]. However, these tech-niques can not be directly applied to IEEE 802.16 because IEEE 802.11 is a CSMA/CA-based (Carrier Sense Multiple Access with Collision Avoidance-based) wireless access protocol. Analyses of IEEE 802.16 networks ’ energy costs are in [5–8]. These results have provided a potential guid-ance for setting PSCs ’ parameters. However, these scheme