Utility-Optimal Dynamic Rate Allocation under Average End-to-End Delay Requirements

TL;DR

This paper introduces a novel distributed rate allocation algorithm, DA-DNUM, that optimizes network utility while satisfying long-term average end-to-end delay constraints for QoS-sensitive applications.

Contribution

It presents a new time-coupling constraint model and a dual-based distributed algorithm for dynamic rate allocation under delay requirements.

Findings

DA-DNUM achieves higher link utilization.

It supports a wider range of delay-constrained scenarios.

Numerical results validate its effectiveness.

Abstract

QoS-aware networking applications such as real-time streaming and video surveillance systems require nearly fixed average end-to-end delay over long periods to communicate efficiently, although may tolerate some delay variations in short periods. This variability exhibits complex dynamics that makes rate control of such applications a formidable task. This paper addresses rate allocation for heterogeneous QoS-aware applications that preserves the long-term end-to-end delay constraint while, similar to Dynamic Network Utility Maximization (DNUM), strives to achieve the maximum network utility aggregated over a fixed time interval. Since capturing temporal dynamics in QoS requirements of sources is allowed in our system model, we incorporate a novel time-coupling constraint in which delay-sensitivity of sources is considered such that a certain end-to-end average delay for each source over a pre-specified time interval is satisfied. We propose DA-DNUM algorithm, as a dual-based solution, which allocates source rates for the next time interval in a distributed fashion, given the knowledge of network parameters in advance. Through numerical experiments, we show that DA-DNUM gains higher average link utilization and a wider range of feasible scenarios in comparison with the best, to our knowledge, rate control schemes that may guarantee such constraints on delay.