Temporal Framework for Causality-Preserving Scheduling of Measurements in Quantum Networks

TL;DR

This paper introduces a time-division scheduling framework for quantum networks that ensures causality preservation in measurement outcomes despite hardware heterogeneity and timing uncertainties.

Contribution

It formalizes a temporal scheduling model with constraints and algorithms to guarantee causal order in quantum measurements across network nodes.

Findings

The proposed framework guarantees unique causal interpretation of measurement outcomes.

An algorithm for optimal measurement scheduling in simple network topologies is presented.

The model bridges classical timing and quantum measurement processing for scalable quantum networking.

Abstract

Distributed quantum protocols rely on classical feedforward information to process measurement outcomes, but heterogeneous hardware and uncertain local timing can make the causal order of measurements ambiguous when inferred solely from arrival times. Even in simple line networks with only Pauli measurements, end nodes cannot distinguish whether a missing outcome is caused by slow measurement or by delayed classical propagation. To resolve this ambiguity, we propose a time-division architecture for quantum networks in which nodes perform measurements in pre-assigned slots, ensuring a unique causal interpretation of outcomes. We formalize this temporal framework and derive the feedforward and adjacency constraints required to preserve measurement causality. For simple network topologies, we present an algorithm that yields optimal measurement schedules. Overall, the proposed time-division model provides a practical coordination layer that bridges the classical network timing with quantum measurement processing, enabling reliable and scalable measurement-based quantum networking.