A load-aware weighted round-robin algorithm for IEEE 802.16 networks

Abstract

Abstract The IEEE 802.16 standard was designed to provide quality-of-service (QoS) guarantees for various classes of traffic with diverse QoS requirements. Packet-scheduling algorithms play a critical role in providing such guarantees. Weighted round robin (WRR) is one of the most commonly used scheduling algorithms, because of its simplicity and low computational overhead. However, it suffers from performance degradation under bursty traffic conditions because of the static weights used to determine packet transmissions. We propose a new packet-scheduling discipline for downlink traffic in 802.16 networks to improve performance in such situations. It dynamically determines the weight of each queue in the various classes based on the current traffic characteristics using the static WRR weight at the beginning of each base station round. The goal is not only to reduce the average delay and packet loss but also to improve average throughput. Simulations are used to evaluate the performance of the proposed algorithm load-aware weighted round robin (LAWRR), and show that it reduces average delay and packet loss, as well as it improves average throughput compared with WRR. The effectiveness of LAWRR running under fixed buffer sizes is also investigated.