A Slot-based BS scheduling with Maximum Latency Guarantee and Capacity First in 802.16e networks

IEEE 802.16e standard defines a wireless broadband access network technology. The standard specifies the QoS support at the MAC level. To meet the QoS requirements, the scheduling algorithm at base station (BS) has to efficiently allocate slots for each connection request. The standard does not specify the detailed algorithm but leaves it open for implementation. In this paper, a Slot-based BS scheduling algorithm with Maximum Latency Guarantee and Capacity First (SMLG-CF) is proposed. With SMLG-CF, the connection is chosen with highest slot capacity first. With the assistance of dynamic sub-frame adjustment, the average system transmission rate can be enhanced. Through the finer slots calculation and proper allocation of transmission time and frequency, the maximum latency guarantee can be achieved for urgent requests. We simulate and compare the proposed mechanism with deficit fair priority queue (DFPQ) scheduling algorithm and Highest Urgency First (HUF) scheduling algorithm in terms of maximum latency violation rate and average transmission rate. The simulation results reveal that the applicability of the proposed mechanism.