Elsevier

Theoretical Computer Science

Volume 409, Issue 3, 28 December 2008, Pages 477-485
Theoretical Computer Science

Deadline guaranteed packet scheduling for overloaded traffic in input-queued switches

https://doi.org/10.1016/j.tcs.2008.09.013Get rights and content
Under an Elsevier user license
open archive

Abstract

Many applications need to solve the deadline guaranteed packet scheduling problem. However, it is a very difficult problem if three or more deadlines are present in a set of packets to be scheduled. The traditional approach to dealing with this problem is to use EDF (Earliest Deadline First) or similar methods. Recently, a non-EDF based algorithm was proposed that constantly produces a higher throughput than EDF-based algorithms by repeatedly finding an optimal scheduling for two classes. However, this new method requires the two classes be non-overloaded, which greatly restricts its applications. Since the overloaded situation is not avoidable from one iteration to the next in dealing with multiple classes, it is compelling to answer the open question: Can we find an optimal schedule for two overloaded classes efficiently? This paper first proves that this problem is NP-complete. Then, this paper proposes an optimal preprocessing algorithm that guarantees to drop a minimum number of packets from the two classes such that the remaining set is non-overloaded. This result directly improves on the new method.

Keywords

Input-queued switch
Packet scheduling
Quality of service
Deadline guarantee
NP-hard

Cited by (0)