Quality of service driven packet scheduling disciplines for real-time applications: looking beyond fairness

Abstract

In this paper we focus on real-time scheduling of "soft" realtime data services such as multimedia data, MPEG video streaming and IP telephony, which can tolerate a small degree of loss or delay. We argue that network operators and service providers should be able to select from a range of Quality of Service objectives, including maximizing the number of customers receiving good service. Further, we argue that scheduling disciplines such as fair queueing are unable to achieve such goals and hence there is a need for alternative approaches. We propose a new scheduling scheme, which we call the Dual Queue discipline. We show that the Dual Queue has the flexibility to satisfy a variety of QoS objectives, ranging from existing notions of fairness through to maximizing the number of customers receiving good service. In addition, even the simplest Dual Queue implementation outperforms Fair Queueing, is scalable in the number of active sessions, and can be made fair, if desired, over moderate to long time scales.Keywords-Quality of Service, packet scheduling, Dual Queue, real-time packet scheduling. 0-7803-541 7-6/99/$10.00 01 999 IEEE.

QoS Mechanisms for IEEE 802.11 Wireless LANs

“…In [35] it is suggested that the fairness is not the best solution and that better results can be obtained by trying to maximize the number of stations whose QoS needs are covered.…”

Waiting time analysis of the multiple priority dual queue with a preemptive priority service discipline

“…It was shown to outperform other scheduling policies with the presence of two queues. Most importantly, [7,13] show the dual queue model, from which this work is extended, to again provide greater QoS than Round Robin, Fair Queueing and FIFO policies.…”

“…The dual queue was introduced in [7] as a device to improve the quality of service (QoS) of customers in communication networks. The dual queue consists of two sub-queues, denoted by queue 1 (the primary queue) and queue 2 (the secondary queue).…”

Achieving differentiated services through multi-class probabilistic priority scheduling

“…Packet scheduling is a crucial technique for performing resource allocation to bring about QoS and service differentiation [6]. Recently, the QoS research community has started considering the concept of relative and proportional differentiated services [7], [8], which are simpler to implement compared to absolute differentiated services.…”