Classical Communication Networks Research Articles

Leveraging quantum uncertainty: Quantum randomness through the lens of classical communication networks

The generation of random numbers and the study of its properties have been an elusive field for a fair portion of the century. The application of random numbers is employed in many use cases such as cryptography, neural networks, numerical simulation, and gambling. The performance of each of these use cases is profoundly impacted by the employed random numbers; henceforth, the quality of randomness is of critical importance when it comes to their usage. A poorly generated random number can make a security system vulnerable, or any numerical or statistical evaluation misleading. Although various modes of classical random number generators exist and still function to provide strong cryptographic properties, emergence of quantum mechanical randomness has shed light on a novel path of generating certified randomness which supersedes the classical counterpart in terms of security. Harnessing quantum mechanical phenomena enables generation of true random numbers which can be certified and further implemented to elevate the net quality of the specific use cases. In this work, we generate and analyze random numbers from three different sources — 50: 50 beam splitter (BS), quantum key distribution (QKD) setup with classical post-processing scheme, and a commercially available quantum random number generator (QRNG) (ID Quantique (IDQ)). The quality of the generated random numbers from the various sources is checked in statistical tests and compared. Further on, we have developed a system which implements the QRNG-based random numbers to facilitate message authentication code (MAC) and one time password (OTP) protocols, demonstrating a communication network application. In this manner we discuss about a network which integrates quantum mechanics to the current classical networking approaches to enhance certain aspects of the networking protocol — in this case, the security.

Message priority MaxDelivery algorithm applied in earthquake communication situation

The study of Delay Tolerant Networks (DTNs) has considerably grown in recent years as communication contexts have emerged with needs that go beyond what the Internet could offer. For example, in case of a natural disaster that damages the classic communication network, a delay tolerant network can be implemented ad hoc, to face the challenges imposed by this context. The delay tolerant network is special because there are no permanent end-to-end path between nodes and links characteristics are time-varying. This paper aims to test the performance of the DTN MaxDelivery algorithm in establishing an efficient communication in the context of a post-earthquake situation, that affected the classical communication network. The goal of the algorithm is to maximize the number of high priority messages that manage to reach their destination. A series of simulations are presented to verify the optimal parameters that the network must comply with in order to maximize the message transfer rate.

Quantum Communication Networks

This book on quantum mechanics is structured into seven chapters with a comprehensive list of over 200 recent references. Quantum mechanics was born over 100 years ago and has attracted fundamental research first in mathematics and physics, then in computing and information theory, and finally in wireless communications. The following topics are covered: the history of the evolution of classical communication networks; the background of quantum mechanics; an understanding of these key quantum ideas that are important in quantum computation; quantum equivalents of basic Shannon information-theoretic tasks; forward error correction codes; future quantum communication architecture; and some interesting use cases for quantum communication networks. Clock synchronization, exchanging Cartesian reference frames, and interferometry. The book prepares the reader to take the next step toward quantum network systems design. The reader is convinced that quantum-mechanical resources will become an important part in the effective and efficient evolution of future wireless communication networks. The book provides all researchers who will enter this exciting field with a valuable reference for the

Employing Interacting Qubits for Distributed Microgrid Control

To empower flexible and scalable operations, distributed control of multi-inverter microgrids, based on classical communication networks among distributed energy resources, has attracted considerable attention as it can guarantee synchronization and provide suitable remedies to the problem of improper power sharing. Notwithstanding this, resilience of the current schemes on classical communication makes microgrids vulnerable to cyber attacks. Inspired by recent revolutionary breakthroughs in quantum communication, in this paper, we devise a novel synchronization mechanism. We extend the synchronization framework utilized in distributed control algorithms to networks of quantum systems by generating pinning terms and coupling mechanism for the new synchronization rule via exploiting proper quantum jump operators and observables, and show that the quantum system will converge to a time-variant target state. Our devised quantum distributed controller (QDC) gives rise to a novel quantum communication scheme for distributed control of microgrids and enables microgrids to exploit the state-of-the-art quantum communication frameworks as communication infrastructure. Test results on two representative AC and DC networked microgrids validate the efficacy and universality of the quantum distributed control.

Advanced Laser Technology for Quantum Communications (Tutorial Review)

AbstractQuantum communications is the art of exchanging and manipulating information beyond the capabilities of the conventional technologies using the laws of quantum mechanics. With applications ranging from quantum computing to cryptographic systems with information‐theoretic security, there is strong incentive to introduce quantum communications into many areas of the society. However, an important challenge is to develop viable technologies meeting the stringent requirements of low noise and high coherence for quantum state encoding, of high bit rate and low power for the integration with classical communication networks, and of scalable and low‐cost production for a practical wide‐deployment. This tutorial presents recent advances in laser modulation technologies that have enabled the development of efficient and versatile light sources for quantum communications, with a particular focus on quantum key distribution (QKD). Such approaches have been successfully used to demonstrate several QKD protocols with state‐of‐the‐art performance. The applications and experimental results are reviewed and interpreted in the light of a complete theoretical background, allowing the reader to model and simulate such sources.

The Computational and Latency Advantage of Quantum Communication Networks

This article summarises the current status of classical communication networks and identifies some critical open research challenges that can only be solved by leveraging quantum technologies. By now, the main goal of quantum communication networks has been security. However, quantum networks can do more than just exchange secure keys or serve the needs of quantum computers. In fact, the scientific community is still investigating on the possible use cases/benefits that quantum communication networks can bring. Thus, this article aims at pointing out and clearly describing how quantum communication networks can enhance in-network distributed computing and reduce the overall end-to-end latency, beyond the intrinsic limits of classical technologies. Furthermore, we also explain how entanglement can reduce the communication complexity (overhead) that future classical virtualised networks will experience.

Leveraging fine-grained mobile data for churn detection through Essence Random Forest

The rise of unstructured data leads to unprecedented opportunities for marketing applications along with new methodological challenges to leverage such data. In particular, redundancy among the features extracted from this data deserves special attention as it might prevent current methods to benefit from it. In this study, we propose to investigate the value of multiple fine-grained data sources i.e. websurfing, use of applications and geospatial mobility for churn detection within telephone companies. This value is analysed both in substitution and in complement to the value of the well-known communication network. What is more, we also suggest an adaptation of the Random Forest algorithm called Essence Random Forest designed to better address redundancy among extracted features. Analysing fine-grained data of a telephone company, we first find that geo-spatial mobility data might be a good long term alternative to the classical communication network that might become obsolete due to the competition with digital communications. Then, we show that, on the short term, these alternative fine-grained data might complement the communication network for an improved churn detection. In addition, compared to Random Forest and Extremely Randomized Trees, Essence Random Forest better leverages the value of unstructured data by offering an enhanced churn detection regardless of the addressed perspective i.e. substitution or complement. Finally, Essence Random Forest converges faster to stable results which is a salient property in a resource constrained environment.

Boosting the secret key rate in a shared quantum and classical fibre communication system

During the last 20 years, the advance of communication technologies has generated multiple exciting applications. However, classical cryptography, commonly adopted to secure current communication systems, can be jeopardised by the advent of quantum computers. Quantum key distribution (QKD) is a promising technology aiming to solve such a security problem. Unfortunately, current implementations of QKD systems show relatively low key rates, demand low channel noise and use ad hoc devices. In this work, we picture how to overcome the rate limitation by using a 37-core fibre to generate 2.86 Mbit s−1 per core that can be space multiplexed into the highest secret key rate of 105.7 Mbit s−1 to date. We also demonstrate, with off-the-shelf equipment, the robustness of the system by co-propagating a classical signal at 370 Gbit s{}^{-1}, paving the way for a shared quantum and classical communication network.

Performance Analysis of Quantum Based Cloud Radio Access Networks

Quantum computing can provide a solution for many problems that classical communication networks encounter, but the knowledge gap between these two is not bridged yet. Accordingly, this paper has proposed directions, evaluations, and futuristic quantum solutions to cloud-based cellular communications. This paper shows the effect of using quantum entanglement phenomena upon the classical cloud network, particularly using an entanglement theory to decrease the enlarged signaling cost delay that the traditional cloud network faces. Through modeling the latency of both paradigms, this paper promises a delay reduction when adapting a quantum method into the mobile cloud networks. This paper also models the power consumption (PC) and energy efficiency of the traditional and quantum-based cloud networks. This paper also shows, via modeling the PC, that installing a quantum-based paradigm is not a power costly method; rather, it shows identical power and energy efficiency figures with a possibility of improvement.

Multiqubit subradiant states in N -port waveguide devices: ε-and-μ-near-zero hubs and nonreciprocal circulators

Quantum emitters interacting through a waveguide setup have been proposed as a promising platform for basic research on light-matter interactions and quantum information processing. We propose to augment waveguide setups with the use of multiport devices. Specifically, we demonstrate theoretically the possibility of exciting $N$-qubit subradiant, maximally entangled, states with the use of suitably designed $N$-port devices. Our general methodology is then applied based on two different devices: an epsilon-and-mu-near-zero waveguide hub and a nonreciprocal circulator. A sensitivity analysis is carried out to assess the robustness of the system against a number of nonidealities. These findings link and merge the designs of devices for quantum state engineering with classical communication network methodologies.

Robust relativistic bit commitment

Relativistic cryptography exploits the fact that no information can travel faster than the speed of light in order to obtain security guarantees that cannot be achieved from the laws of quantum mechanics alone. Recently, Lunghi et al [Phys. Rev. Lett. 2015] presented a bit commitment scheme where each party uses two agents that exchange classical information in a synchronized fashion, and that is both hiding and binding. A caveat is that the commitment time is intrinsically limited by the spatial configuration of the players, and increasing this time requires the agents to exchange messages during the whole duration of the protocol. While such a solution remains computationally attractive, its practicality is severely limited in realistic settings since all communication must remain perfectly synchronized at all times. In this work, we introduce a robust protocol for relativistic bit commitment that tolerates failures of the classical communication network. This is done by adding a third agent to both parties. Our scheme provides a quadratic improvement in terms of expected sustain time compared to the original protocol, while retaining the same level of security.

Orthogonal spectral coding of entangled photons.

We extend orthogonal optical coding, previously applied to multiuser classical communication networks, to entangled photons. Using a pulse shaper and sum-frequency generation for ultrafast coincidence detection, we demonstrate encoding and decoding of biphoton wave packets. Applying one code to the signal photon spreads the wave packet in time and creates a null at zero delay; filtering the idler with the matched code recovers a narrow correlation peak, whereas applying any other code leaves the wave packet spread. Our results could prove useful in the development of code-based quantum communication networks.

Quantum Key Distribution in Large Scale Quantum Network Assisted by Classical Routing Information

Recently, small-scale Quantum Key Distribution (QKD) networks have been demonstrated and continuously operated in field environment. However, nodes of these QKD networks are less than 10 nodes. When the scale and structure of these networks becomes large and complex, such networks will subject to problem of intractable routing selection and limited transmission distance. We present a novel quantum network model and the corresponding protocol to solve these problems. The proposed quantum network model integrates classical communication network with quantum key distribution layer. Nodes in this quantum network model are divided into communication nodes for classical communication and quantum nodes for quantum key distribution. We use atomic ensembles to create entangled photons inside quantum nodes. Quantum repeaters are used to establish entanglement between remote quantum nodes so the maximum distribution distance of entangled photons can be extended. The main idea is to establish an appropriate key distribution path in the quantum key distribution layer based on the routing information obtained by the upper classical communication network. After the entanglement has been established between remote quantum nodes, these nodes will use the Ekert91 or BBM92 protocol to generate secret keys shared between each other. Then, these keys can be used to ensure the security of communication in the classical communication network.

Social Groups, Social Media, and Higher Dimensional Social Structures: A Simplicial Model of Social Aggregation for Computational Communication Research

By building on classical communication network literature, we present a computational approach to modeling tightly bound groups and social aggregations as higher dimensional social structures. Using the mathematical theory of simplicial complexes, these groups can be represented by geometric spatial elements (or simplexes) and a social aggregation a collection of simplexes (i.e., a simplicial complex). We discuss the uniting conditions that define a tightly bound group as a higher-dimensional group, which can be mathematically treated as nodes in a network of social aggregation. We utilize Facebook as a particularly relevant example to demonstrate innovative ways researchers can tap into digital data, in addition to traditional self-reported data, to advance communication research using the simplicial model, although the approach is applicable to many questions not involving communication technology.