Energy-efficient packet scheduling algorithms for real-time communications in a mobile WiMAX system

Broadband wireless access systems usually provide flexible sleep-mode operations for mobile stations to conserve their energy during idle or active mode. For example, Mobile WiMAX, i.e. the IEEE 802.16e, offers several power-saving classes that can be associated with different types of network connections to minimize power consumption of mobile stations. Unfortunately, previous studies did not fully utilize the sleep-mode features to save the energy of a mobile station with multiple real-time connections, and power consumption of a mobile station is not yet optimized. In this work, two energy-efficient packet scheduling algorithms for real-time communications in a Mobile WiMAX system are proposed. The schemes not only guarantee the quality of services (QoSs) of real-time connections but also minimize power consumption of mobile stations. Simulation results demonstrate that the proposed schemes outperform the traditional approach. (C) 2008 Elsevier B.V. All rights reserved.