The mechanism of transferring and routing information in quantum and classical network are basically different. The basic idea and working principle of quantum networks is based on a unique feature of quantum mechanics known as entanglement. Since entanglement generation rate is a key factor for quantum networks it can be considered as a route metric. In this paper, we propose two different protocols for local entanglement routing in a quantum ring network. In the first protocol, local link entanglement rate is considered as a route metric. However, the routing decision in the second protocol is made based on finding the shortest path between source and destination. It is shown that though local link entanglement rate is decisive criterion for routing in the first algorithm, the second algorithm can reach higher end-to-end entanglement rate.
The mechanism of transferring and routing information in quantum and classical network are basically different. The basic idea and working principle of quantum networks is based on a unique feature of quantum mechanics known as entanglement. Since entanglement generation rate is a key factor for quantum networks it can be considered as a route metric. In this paper, we propose two different protocols for local entanglement routing in a quantum ring network. In the first protocol, local link entanglement rate is considered as a route metric. However, the routing decision in the second protocol is made based on finding the shortest path between source and destination. It is shown that though local link entanglement rate is decisive criterion for routing in the first algorithm, the second algorithm can reach higher end-to-end entanglement rate.
This paper proposes a novel distributed routing protocol for quantum networks leveraging the topological properties of quantum entanglement. The core idea is to construct a network topology based on entangled states between nodes, enabling communication through the instantaneous correlation inherent in entanglement. This approach aims to overcome the limitations of traditional routing protocols, particularly in terms of speed and security. We define a routing algorithm that dynamically adjusts the entanglement states to facilitate data transmission, effectively creating a network with inherently high bandwidth and resilience to eavesdropping. The algorithm is based on a graph theory framework where nodes represent quantum devices and edges represent entangled pairs. The routing process involves identifying the shortest path through the entanglement network, leveraging the correlated states for rapid information transfer. We explore the mathematical underpinnings of this protocol, outlining key formulas for calculating entanglement metrics, path distances, and routing decisions. The theoretical framework presented here provides a foundation for future research and development in quantum network architecture and routing strategies.
Due to the fact that quantum networks can provide higher security in communications, many related issues have been presented and addressed recently. One of the most important issues is to study the routing in quantum networks with multiple source-destination pairs while maximizing the total end-to-end entanglement rate. In previous studies, the shortest paths are typically selected as the entanglement paths for a source-destination pair to increase the total end-to-end entanglement rate. However, this approach is only efficient once the network resources are sufficient. Moreover, source-destination pairs only require a specific entanglement rate rather than the shortest paths. Therefore, in this paper, we suppose that each source-destination pair requires an upper bound of the entanglement rate. Under this assumption, a novel problem is proposed to construct entanglement paths for a set of multiple source-destination pairs such that the total end-to-end entanglement rate is maximized. We then propose a greedy algorithm to solve the problem. Finally, the simulation is conducted to evaluate the performance of the proposed algorithm.
To fully unleash the potentials of quantum computing, several new challenges and open problems need to be addressed. From a routing perspective, the optimal routing problem, i.e., the problem of jointly designing a routing protocol and a route metric assuring the discovery of the route providing the highest quantum communication opportunities between an arbitrary couple of quantum devices, is crucial. In this paper, the optimal routing problem is addressed for generic quantum network architectures composed by repeaters operating through single atoms in optical cavities. Specifically, we first model the entanglement generation through a stochastic framework that allows us to jointly account for the key physical-mechanisms affecting the end-to-end entanglement rate, such as decoherence time, atom-photon and photon-photon entanglement generation, entanglement swapping, and imperfect Bell-state measurement. Then, we derive the closed-form expression of the end-to-end entanglement rate for an arbitrary path and we design an efficient algorithm for entanglement rate computation. Finally, we design a routing protocol and we prove its optimality when used in conjunction with the entanglement rate as routing metric.
Quantum networks enable a number of important applications such as quantum key distribution. The basic function of a quantum network is to enable long-distance quantum entanglement between two remote communication parties. This work focuses on the entanglement routing problem, whose objective is to build long-distance entanglements for the concurrent source-destination pairs through multiple hops. Different from existing works that analyzes the traditional routing techniques on special network topologies, we present a comprehensive entanglement routing model that reflects the differences between quantum networks and classical networks and new entanglement routing algorithms that utilize the unique properties of quantum networks. Evaluation results show that the proposed algorithm Q-CAST increases the number of successful long-distance entanglements by a big margin compared to other methods. The model and simulator developed by this work may encourage more network researchers to study the entanglement routing problem.
A quantum repeater is the heart of a quantum internet that enables end-to-end communication over long distances using the quantum entanglement feature. Although this characteristic gives quantum networks tremendous power in terms of speed and security, it puts quantum networks, especially the quantum internet, in front of challenges, like transforming a short-distance quantum link into a long-distance link, in addition to entanglement routing for finding the best path within a quantum network. So, this research aims to propose a hybrid quantum routing protocol (HQRP) based on routing metrics of the classical networks like hops count, as well as metrics of the quantum network represented by the possibility of entanglement between end nodes in the network. As a result, a mathematical model was built to determine the optimal path among many paths within the quantum network, and it was implemented on our quantum network simulator. Finally, we concluded that the proposed algorithm gives the optimal path based on the highest entanglement probability and lowest number of hop count.
The quantum internet is a global system also called the future internet and is considered a complement to the classical packet switching internet, which performs the function of exchanging messages in the network in an innovative way, as it depends on the basic principles of quantum bits. In order to prepare for the quantum internet, its protocols must be configured initially like routing protocols, and because routing in the quantum internet depends mainly on the property of quantum entanglement, it is facing a constant challenge to what the quantum properties impose, Accordingly, studies in this field continue to emerge, as proposals for protocols are renewed. Therefore, in this research, we present a comprehensive study of the recently proposed quantum routing protocols by classifying these protocols into two categories, the first deals with the routing metrics on which the protocol depends, while the other deals with the problem being solved through the routing protocol. It is shown that although many metrics were suggested for routing protocols, the common metric was the throughput (entanglement rate), In addition, it was considered an essential metric in solving most of the routing problems in quantum networks.