The Impact of the Quantum Data Plane Overhead on the Throughput

Currently, although a standard distinction between quantum data plane and quantum control plane is still missing, preliminary works specify that classical control messages operating at the granularity of individual qubits and entangled pairs are, in terms of functionalities, closer to classical packet headers than control plane messages. Thus, they have been considered as part of the quantum data plane, by contributing to its overall overhead. As a consequence, the very concept of throughput needs to be re-defined and studied within the Quantum Internet. The aim of this treatise is to shed the light on this crucial aspect. Specifically, we conduct a theoretical analysis to understand the factors determining the overhead in the quantum data plane and their reflection on the throughput. The analysis is crucial and preliminary for designing any effective quantum communication protocol. Specifically, we derive closed-form expressions of the throughput in different scenarios, and the nonlinear relationship between throughput, entanglement throughput and classical bit rate is disclosed. Finally, we validate the theoretical analysis through numerical results conducted on the IBM Q-Experience platform.