SI-WF2Q: WF2Q Approximation with Small Constant Execution Overhead

Abstract

This paper presents a novel priority queue data structure and access operations for timer maintenance in the context of traffic shaping and scheduling in packet networks. The data structure and operations are used to construct an efficient General Processor Sharing (GPS) approximation scheduler. In contrast to existing proposals, this scheduler has constant and near-optimal delay and fairness properties, and can be implemented with bounded amortized O(1) algorithmic complexity, and has very low absolute execution overhead. The paper presents the data structure, the scheduling algorithm, and studies its execution complexity. The scheduling properties are analyzed and shown to relate nicely to existing work. Some illustrative simulation results are presented to reaffirm those properties.