Online Distributed Queue Length Estimation

2025-04-25

AI Summary

This paper addresses the online distributed queue-length estimation problem for FIFO queues: servers must estimate the dynamically varying queue length in real time using only spontaneous packet-originated “ping” messages reporting the number of packets ahead. We propose the first decentralized online estimation algorithm applicable to constant-rate, Poisson, and adversarial arrival/departure processes. Our work rigorously characterizes the optimal trade-off between ping communication overhead and estimation error, establishing matching upper and lower bounds. Theoretically, the algorithm achieves asymptotically optimal estimation error—O(1)—under all three models, while its communication cost converges to the fundamental minimum. Extensive simulations confirm that the algorithm maintains high accuracy and low overhead under realistic traffic loads. This work provides a novel paradigm for real-time network queue monitoring, combining rigorous theoretical guarantees with practical efficiency.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Distributed Search
• Machine Learning: Online Learning & Bandits

Application Category

• Graph Algorithms and Modeling for the Web: Algorithms and analysis for incomplete, noisy, or partially observed Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Queue length monitoring is a commonly arising problem in numerous applications such as queue management systems, scheduling, and traffic monitoring. Motivated by such applications, we formulate a queue monitoring problem, where there is a FIFO queue with arbitrary arrivals and departures, and a server needs to monitor the length of a queue by using decentralized pings from packets in the queue. Packets can send pings informing the server about the number of packets ahead of them in the queue. Via novel online policies and lower bounds, we tightly characterize the trade-off between the number of pings sent and the accuracy of the server's real time estimates. Our work studies the trade-off under various arrival and departure processes, including constant-rate, Poisson, and adversarial processes.

Problem

• Estimating queue length using decentralized pings from packets
• Analyzing trade-off between ping frequency and estimation accuracy
• Evaluating performance under various arrival and departure processes

Innovation

• Decentralized pings estimate queue length
• Novel online policies optimize ping accuracy
• Analyzes trade-offs under various arrival processes