Efficient and fair scheduling of rtPS traffic in IEEE 802.16 point-to-multipoint networks

IEEE 802.16 standard provides a revolutionary air interface that enables very high data rates over large distances. It incorporates a Quality of Service (QoS) framework to ensure satisfactory transmission of different classes of traffic. However, the actual implementation of QoS mechanisms is not defined in the standard and left out for service providers. One of the five different classes of services supported by the standard is real-time polling service (rtPS). Scheduling rtPS traffic is the most challenging because of its bursty nature and tight delay constraints. In this paper, we provide a new algorithm for fair scheduling of rtPS traffic in the uplink direction. Besides the constraint of deadline which characterizes this type of traffic, we also assure fairness by using service ratios for each service flow. Performance analysis of the proposed algorithm proves that the algorithm is able to fairly allocate maximum possible bandwidth among all admitted rtPS connections. Furthermore, it shows improvement of various QoS parameters compared to Earliest Deadline First algorithm, particularly for high speed data networks.