DMWRR: A QoS Scheduling for the Delay Fairness

In recent years, an explosive growth of network applications can be obviously observed. This results in different traffic patterns which need different QoS requirements. For supporting various QoS requirements, it is necessary to implement some QoS control and scheduling mechanisms in multimedia communication networks. The QoS scheduler(s) in a switch, router, or multiplexer can provide different service rate to satisfy specified delay guarantee and then the delay fairness when bursty traffic happens. However, a static scheduler is easily implemented but poor in tackling burstiness, and a dynamic scheduler is adaptive to network status but complex in computation. In this paper, we propose a scheduling algorithm for packets of non-fixed sizes, called Deadline Modulating Weighted Round Robin (DMRRR), which is based on WRR and the concept of VirtualClock (VC). The scheduling pattern of DMWRR is static under regular network status, while dynamically adapted under bursty traffic. It keeps the simplicity of static scheduling and the adaption of dynamical scheduling. Simulation results show that the DMWRR can meet the QoS requirement better than WRR but skip the computation complexity of VC-VFT.