Optimal queue-size scaling in switched networks

TL;DR

This paper introduces a new class of online scheduling policies for switched networks that achieve optimal queue-size scaling, confirming a longstanding conjecture for input-queued switches and improving network performance.

Contribution

It presents a novel scheduling policy that guarantees optimal queue-size scaling in switched networks, including input-queued switches, validating a prior conjecture.

Findings

Achieves optimal queue-size scaling in switched networks.

Validates a conjecture about input-queued switches.

Provides a new class of online scheduling policies.

Abstract

We consider a switched (queuing) network in which there are constraints on which queues may be served simultaneously; such networks have been used to effectively model input-queued switches and wireless networks. The scheduling policy for such a network specifies which queues to serve at any point in time, based on the current state or past history of the system. In the main result of this paper, we provide a new class of online scheduling policies that achieve optimal queue-size scaling for a class of switched networks including input-queued switches. In particular, it establishes the validity of a conjecture (documented in Shah, Tsitsiklis and Zhong [Queueing Syst. 68 (2011) 375-384]) about optimal queue-size scaling for input-queued switches.