Service-the-Longest-Queue Among d Choices Policy for Quantum Entanglement Switching

Yau, Guo Xian; Vasantam, Thirupathaiah; Vardoyan, Gayane

Abstract

An Entanglement Generation Switch (EGS) is a quantum network hub that provides entangled states to a set of connected nodes by enabling them to share a limited number of hub resources. As entanglement requests arrive, they join dedicated queues corresponding to the nodes from which they originate. We propose a load-balancing policy wherein the EGS queries nodes for entanglement requests by randomly sampling d of all available request queues and choosing the longest of these to service. This policy is an instance of the well-known power-of-d-choices paradigm previously introduced for classical systems such as data-centers. In contrast to previous models, however, we place queues at nodes instead of directly at the EGS, which offers some practical advantages. Additionally, we incorporate a tunable back-off mechanism into our load-balancing scheme to reduce the classical communication load in the network. To study the policy, we consider a homogeneous star network topology that has the EGS at its center, and model it as a queueing system with requests that arrive according to a Poisson process and whose service times are exponentially distributed. We provide an asymptotic analysis of the system by deriving a set of differential equations that describe the dynamics of the mean-field limit and provide expressions for the corresponding unique equilibrium state. Consistent with analogous results from randomized load-balancing for classical systems, we observe a significant decrease in the average request processing time when the number of choices d increases from one to two during the sampling process, with diminishing returns for a higher number of choices. We also observe that our mean-field model provides a good approximation to study even moderately-sized systems.

Citation

Yau, G. X., Vasantam, T., & Vardoyan, G. (2025, March). Service-the-Longest-Queue Among d Choices Policy for Quantum Entanglement Switching. Presented at QCNC2025: International Conference on Quantum Communications, Networking, and Computing, Nara, Japan

• Presentation Conference Type: Conference Paper (published)
• Conference Name: QCNC2025: International Conference on Quantum Communications, Networking, and Computing
• Start Date: Mar 31, 2025
• End Date: Apr 2, 2025
• Acceptance Date: Jan 22, 2025
• Online Publication Date: May 15, 2025
• Publication Date: May 15, 2025
• Deposit Date: Feb 21, 2025
• Publicly Available Date: May 28, 2025
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Book Title: 2025 International Conference on Quantum Communications, Networking, and Computing (QCNC)
• ISBN: 9798331531607
• DOI: https://doi.org/10.1109/QCNC64685.2025.00011
• Public URL: https://durham-repository.worktribe.com/output/3492388