Communication Network Architecture Research Articles

Методика экспресс-анализа устойчивости функционирования мультисервисной сети связи

Continuous improvement of the architecture of multi-service communication networks (MCN) is due to the need for networks with a capacity of tens of Tbit/s. Existing communication networks are multi-pole and, in this regard, the term "network bandwidth" loses its meaning. Based on this, the term "network performance" is used. Such performance requires the development of methods for complex analysis of network stability and organization of its functioning. Usually, the network stability is considered in two aspects: potential and structural. This article discusses the models of stability and functioning of IP networks with route parallelism, as well as the method of express analysis of their stability.

Multiple Access in Cognitive Radio Networks: From Orthogonal and Non-Orthogonal to Rate-Splitting

Due to the increasingly complicated communication scenarios and network architectures as well as growing traffic demands for high speed connectivity, dynamic spectrum allocation in fifth generation (5G) networks becomes insufficient to guarantee the satisfaction of main network requirements in terms of spectrum efficiency (SE), scalability, delay, and energy efficiency (EE). Enormous multiple access schemes and cognitive radio (CR) network scenarios come to fulfill these requirements and enhance network functionalities. With multiple access schemes, users are able to transmit their data streams simultaneously under maximum capacity constraints. On the other hand, vacant spectrum holes are exploited in an opportunistic manner via CR and software defined radio. In order to exploit these spectrum holes as well as meeting different network requirements, several multiple access techniques have been presented that have been initiated through the adoption of orthogonal multiple access (OMA) scheme. Additionally, non-orthogonal multiple access (NOMA) and space division multiple access (SDMA) are presented to achieve a promising multiplexing gain as well as to address the inefficient spectrum utilization incurred with OMA schemes. However, such multiplexing gain is limited as it depend on the channel conditions. Accordingly, a generalized multiple access scheme has been presented recently, namely rate splitting multiple access (RSMA), to further enhance the SE. In this paper, we provide a comprehensive study regarding the key multiple access schemes presented for CRNs to further enhance the use of spectral resources, and additionally highlights the key implementation challenges and the enabling techniques addressed to overcome it. We have given a special attention to the enhances provided by RSMA as compared with OMA, SDMA, and NOMA techniques. Finally, some open issues are spotted to shed lights on the need for further studies and future research efforts.

Опыт организации коммуникационных сетей передачи данных СВИ в системах мониторинга и управления

Changing the characteristics of modern power system associated with the introduction of renewable energy sources and technologies for flexible control of the power system operation mode. This necessitates changing requirements to the functionality of Protection, Automation and Control Systems (PACS). These requirements are based on the need to adapt the PACS algorithms to the new operating conditions of the power system and consider advances in digital technology and information and communication technology. One of the most important conditions for solving this problem is the need to use in PACS the information about the processes of new quality occurring in the power system. Currently, the technology that provides measurement of electric modes parameters of power system with standardized accuracy and time synchronization not exceeding 1 µs, as well as data transmission over arbitrarily long distances with minimal delay and data losses is synchrophasor technology. Development of software based on synchrophasor technology and its implementation for monitoring and control of the electric mode of the power system leads to a constant increase in the amount of data transmitted to the control centers of the System operator and puts forward additional requirements to improve the quality of information received. Therefore, there is a task of maximum use of the resource of existing communication networks, which requires the adoption of complex technical solutions related to the optimization of the architecture of communication networks, improvement of information transfer technologies, organization of automatic life cycle monitoring of PACS (WAMPAC). The paper presents the practical experience and research results of the System operator on the organization of communication networks, providing reliability in the transmission of a large amount of data in real time with the necessary quality for their application in monitoring and control tasks in real time.

Impact of Quality of Repairs and Common Cause Failures on the Reliability Performance of Intra-Bay IEC 61850 Substation Communication Network Architecture Based on Markov and Linear Dynamical Systems

Modernisation of substations using digital-based Substation Communication Networks (SCN) enables the automation of substations, allowing effective and efficient monitoring of substation equipment and implementing complex control and protection schemes. The IEC 61850 standard for SCN’s objective is to integrate substation devices from different vendors, enabling peer-to-peer communication between the devices. The reliability investigation of the IEC 61850 based SCN architecture continues since it is left to the system designer to determine based on the network’s applications and functions. In all endeavours to designing highly available SCN architectures, redundant systems are employed in mission-critical applications. In this paper, the impact of Common Cause Failures (CCF) and the quality of repairs on the reliability performance of IEC 61850 based architecture are investigated using the Markov process and Linear Dynamical Systems, where the diagnostic coverage level of the system is based on the ISO 13849-1. The results of the case studies indicate that common engineering design and coupling factors have a negative impact on the system reliability performance, notably for systems with high diagnostic coverage. The results also indicate that the factors have less impact when the system diagnostic coverage is low, specifically at low repair efficiency levels. However, the impact becomes more pronounced as the repair efficiency increases, as observed from the responses of the transition probability matrix’s eigenvalue magnitudes. Thus, it is critical to ensure the minimum impact of common engineering design and coupling factors by diversifying the system’s subsystems to ensure a high independence level.

Comparison of secondary equipment redundancy configuration of smart substations in China and overseas

This paper introduces the overseas smart substation technology scheme, describes the communication network architecture and equipment redundancy configuration in the typical overseas test smart substation scheme, and compares the similarities and differences between China’s smart substation redundancy configuration technology and the overseas smart substation configuration technology. The distribution of measurement and control functions of overseas smart substations that are different from China’s designs are explained in detail. The different architectures of overseas smart substations and China’s smart substations are illustrated. Finally, the suggestions of overseas Smart Substation and China’s smart substation are summarized.

AI-Enabled Next-Generation Communication Networks: Intelligent Agent and AI Router

Nowadays, network users' demands for low latency services and individual data security grow rapidly. In this article, we conceive a new communication network architecture based on the concept of intelligent agents. The proposed intelligent agent serves as a virtual secretary of the corresponding user to request desired service from Internet companies or neighboring agents, which can reduce Internet surfing latency and prevent privacy leakage. Moreover, to improve the forwarding efficiency of data packages, a new mixed routing structure and the AI router are also introduced, to support various on-demand services with low latency. Overall, the proposed communication network architecture is expected to be more efficient than the existing one, and inspire readers to deliberate the revolution of future communications networks.

Performance of Communication Network for Monitoring Utility Scale Photovoltaic Power Plants

The grid integration of large scale photovoltaic (PV) power plants represents many challenging tasks for system stability, reliability and power quality due to the intermittent nature of solar radiation and the site accessibility issues where most PV power plants are located over a wide area. In order to enable real-time monitoring and control of large scale PV power plants, reliable two-way communications with low latency are required which provide accurate information for the electrical and environmental parameters as well as enabling the system operator to evaluate the overall performance and identify any abnormal conditions and faults. This work aims to design a communication network architecture for the remote monitoring of large-scale PV power plants based on the IEC 61850 Standard. The proposed architecture consists of three layers: the PV power system layer, the communication network layer, and the application layer. The PV power system layer consists of solar arrays, inverters, feeders, buses, a substation, and a control center. Monitoring parameters are classified into different categories including electrical measurements, status information, and meteorological data. This work considers the future plan of PV power plants in Saudi Arabia. In order to evaluate the performance of the communication network for local and remote monitoring, the OPNET Modeler is used for network modeling and simulation, and critical parameters such as network topology, link capacity, and latency are investigated and discussed. This work contributes to the design of reliable monitoring and communication of large-scale PV power plants.

Wireless network architecture for evacuated tube transportation system

Evacuated Tube Transportation (ETT) systems have been claimed to have considerable strengths, including ultra-highspeed, safety, and environmentally-friendly. However, the frequent handover caused by the high-speed brings a challenge for ETT mobile wireless communication to preserve steady link performance. Moreover, in such a special scenario, the wireless link between the base station and the passengers on the train needs to experience fading from both metal pipe and train, thus the free-wave coverage with antennas in traditional high-speed rail wireless communication systems is not suitable for ETT. Based on the characteristics of ETT, an improved architecture of wireless communication network is proposed, using distributed base stations with remote radio units (RRUs) and baseband units (BBUs) and leaky waveguides to form stable coverage. And a redundant BBUs or RRUs structure is designed for coverage enhancement. Based on this redundant architecture, a fast handover scheme is proposed to resolve the handover problem. The analytical and simulation results show that the proposed scheme is capable of reducing communication outage probability and handover failure probability remarkably.

COMMUNICATION NETWORK AND QOS EVALUATION FOR FORMATION CONTROL OF UNMANNED SURFACE VEHICLES

The main purpose of this article is to design efficient communication networks for the formation control of multiple distributed Unmanned Surface Vehicles (USVs). First, a hybrid communication network architecture, combining remote communication and wireless Ad hoc network technology is proposed. Second, an improved Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is adopted to prolong the life cycle of the communication network of the USV fleet. Subsequently, some QoS indicators of the USV communication network are evaluated by establishing wireless network channel model and Signal to Interference and Noise Ratio (SINR) model. In particular, the packet error ratio, average time delay and connectivity under different formation architecture are investigated. Finally, some discussions and future work on the QoS of the USV communication network are concluded.

Analyzing control properties of multi-agent linear systems

The networked multi-agent systems that they are interconnected via communication channels have great applicability in multiple areas, such as power grids, bioinformatics, sensor networks, vehicles, robotics and neuroscience, for example. Consequently, they have been widely studied by scientists in different fields in particular in the field of control theory. Recently an interest has grown to analyze the control properties as consensus controllability and observability of multi-agent dynamical systems motivated by the fact that the architecture of communication network in engineering multi-agent systems is usually adjustable. In this paper, we analyze how to improve the control properties in the case of multiagent linear time-invariant dynamical systems.

Game Theory-Based Multi-Objective Optimization Interference Alignment Algorithm for HSR 5G Heterogeneous Ultra-Dense Network

The high-speed railway wireless communication network architecture is gradually transforming from a traditional GSM-Railway (GSM-R) cellular network to a 5G heterogeneous ultra-dense communication network. How to effectively deal with the interference while obtaining the capacity gain has become an inevitable problem. This article proposes a power allocation interference alignment algorithm based on game equilibrium with the goal of joint optimization about throughput and energy efficiency for imperfect channels in high-speed railway communication. Firstly, the imperfect Channel State Information including delay and fading is calculated. Then, in order to improve system throughput and energy efficiency, we establish a game model and prove the existence of Nash equilibrium in the model. At the same time, a power allocation iterative algorithm based on Recurrent Neural Network is proposed. Finally, combined with the interference alignment algorithm based on a maximal signal-to-noise ratio, the optimal power matrix is calculated by iteration to achieve interference management optimization. The simulation results prove that our algorithm has superior performance in improving the system throughput, energy efficiency and transmission reliability in high-speed railway wireless communication with imperfect channels.

Mobile neural intelligent information system based on edge computing with interactive data

With the increasing popularity of smart mobile terminals, smartphones, tablet computers and other mobile devices will gradually replace personal computers and become the most important computing platform for consumers. Mobile edge computing (MEC), as a key technology for the evolution of communication network architecture, can meet the requirements of the system for throughput, delay, network scalability and intelligence. Based on the MEC, the content and services provided by information system are closer to users to increase mobile network speed, reduce latency and improve connection reliability. In this paper, we propose an interactive data information system based on mobile edge detection, which is divided into client and server. The server mainly provides services such as content and user login and rights management for the client. The client needs to log into the server to run normally. Among them, the interactive data server is a favorable support and guarantee for the client. The experimental results show that the proposed method has higher efficiency and fault tolerance.

Consensus‐based operational framework for self‐healing in multi‐microgrid systems

Recently, microgrids (MGs) present a vital role in the transformation of the existing power networks to the smart grids. Connecting MGs to construct the multi-microgrid (MMG) system enhances the robustness of the system against disturbances and upgrades overall network performance. In this paper, the MMG, as a source of self-healing support to the distribution networks, is analysed extensively. In fact, the MMG strengthens the self-healing of the network by participating in the restoration of disturbed loads. In this study, an operational framework is proposed for the self-healing problem in radial interconnected MGs based on two-stage cyber communication network architecture. In the first stage, the local control system (LCS) within each MG, schedules the accessible resources according to the local power consumption target. In the second stage, a number of LCSs are communicated globally to perform self-healing action. The communication of LCSs is accomplished using a consensus algorithm. Nevertheless, when a fault takes place in MG and a line is eliminated, the healthy MGs, due to demand and supply information in the first stage, supply the on-outage loads as far as possible. To validate the effectiveness of the proposed framework, two benchmark distribution networks (the 33-bus and the 119-bus) are employed.

5G Key Technologies for Smart Railways

Railway communications has attracted significant attention from both academia and industries due to the booming development of railways, especially high-speed railways (HSRs). To be in line with the vision of future smart rail communications, the rail transport industry needs to develop innovative communication network architectures and key technologies that ensure high-quality transmissions for both passengers and railway operations and control systems. Under high mobility and with safety, eco-friendliness, comfort, transparency, predictability, and reliability. Fifth-generation (5G) technologies could be a promising solution to dealing with the design challenges on high reliability and high throughput for HSR communications. Based on our in-depth analysis of smart rail traffic services and communication scenarios, we propose a network slicing architecture for a 5G-based HSR system. With a ray tracing-based analysis of radio wave propagation characteristics and channel models for millimeter wave (mmWave) bands in railway scenarios, we draw important conclusions with regard to appropriate operating frequency bands for HSRs. mymargin Specifically, we have identified significant 5G-based key technologies for HSRs, such as spatial modulation, fast channel estimation, cell-free massive multiple-input-multiple-output (MIMO), mmWave, efficient beamforming, wireless backhaul, ultrareliable low latency communications, and enhanced handover strategies. Based on these technologies, we have developed a complete framework of 5G technologies for smart railways and pointed out exciting future research directions.

Analysis of network topology and deployment mode of 5G wireless access network

Aiming at the characteristics of high-density and random deployment of 5G cellular networks, through efficient network-level deployment methods, the network can quickly and efficiently adapt to large-scale dynamic changes in user traffic. Aiming at the need for 5G systems to meet the requirements of high-speed mobile environment communications, this paper deeply studies the factors that affect communication quality in mobile scenarios and their relationships. Based on this, around the content transmission and distribution of information, a 5G mobile communication network architecture based on content-centric network technology is proposed. To meet the deployment requirements of cross-domain VNF (Virtual Network Function) during the deployment phase, in order to solve the problem that the existing cross-domain deployment algorithms do not take into account node computing resources and link bandwidth resources, this paper proposes a DPSO-K (Discrete Particle Swarm Optimization—Kruskal) 5G cross-domain virtual network function deployment method. Compared with the traditional method, the overall cost is reduced, and the cost is least affected by the number of data fields. In different practical scenarios, the resource reduction gain of the strategy is evaluated. Simulation results verify the impact of different system parameters on the energy efficiency of the network. The results show that this method has obvious advantages in optimizing the energy spectrum efficiency of randomly deployed networks.

Edge Computing-Based Privacy-Preserving Authentication Framework and Protocol for 5G-Enabled Vehicular Networks

Based on the functional characteristics of inter-vehicle communication networks under the current framework, a privacy-preserving authentication framework that combines fifth-generation communication technology (5G) and edge computing technology is proposed. The proposed framework is different from that used in the previous 802.11p-based inter-vehicle communication network architecture, and we use device-to-device technology to achieve communication between vehicles. One difference between a 5G-enabled model and a traditional model for vehicle ad hoc networks is that secure communication between vehicles in a 5G-enabled model is challenging. The authentication protocol proposed in this study can be divided into two parts. The first part involves authenticating and selecting an edge computing vehicle, wherein a fuzzy logic mathematical method is used in the selection process. The second part is the mutual authentication between edge computing and ordinary vehicles. In this process, the exchange of security information between vehicles in a group is possible. Simultaneously, the identity privacy and traceability of the vehicle are ensured. Moreover, the proposed signature scheme is proved to be secure under a random oracle model. Performance evaluation results demonstrate that our proposed scheme has relatively lower computational and communication overhead than existing schemes.

A Zeno-Free Event-Triggered Secondary Control for AC Microgrids

This paper proposes a secondary voltage, frequency, and active power sharing control for autonomous inverter-based microgrids with event-triggered communications. A proportional-integral consensus-based control scheme is introduced which benefits from need-based (event-triggered) data exchange among distributed generators. The employed event-triggering condition i ) ensures the system stability, ii ) ensures that the system is Zeno-free and there exists a controllable minimal inter-event time, iii ) removes the redundant communications during both transient and steady-state stages, iv ) accounts for directed communication network architectures, and v ) is fully distributed from both design and implementation standpoints. Effectiveness of the proposed controller for various case studies is verified via MATLAB/Simulink-based simulations. Comparison between different cases and conventional strategies are also included.

An Energy Efficient Network Architecture and Spectrum Sharing Technique for Cognitive Radio Based Smart Grid Communications

With the introduction of an automated electric power system known as smart grid, issues relating to power quality, shortages and inefficiency have been solved. Two vital foundations necessary for the sustainability and the stability of Smart Grids (SG) are a resourceful and reliable communication between users in a smart grid network and an energy efficient Smart Grid Communication Network (SGCN) architecture. On the other hand, Cognitive radios (CR) are equipped with the capability of exploiting unused licensed spectrum resources for effective spectrum utilization. The objective of this paper is to integrate cognitive radio into smart grid communication network in order to make the network a lot smarter and provide spectrum sharing solutions in SGCN. In this paper, an energy efficient SGCN architecture that is layered into the Home Area Network (HAN), Neighbourhood Area Network (HAN) and the Wide Area Network (WAN) has been proposed. Furthermore, in order to achieve a fair spectrum sharing amongst users in the network, CR users in the HANs estimate the need of its neighbouring users to transmit data. Then it uses this information to predict the vacant channels that will be utilized by any node in the network using a Markov chain process. In the NANs, a model is also proposed where every user sensor node access the spectrum based on the buffer occupancy estimates of its neighboring nodes. Simulation results show that there is a higher throughput in the network and also an increase in the quantity of data packets successfully transmitted using the proposed model.

Comparative Analysis of 5G Mobile Communication Network Architectures

Mobile communication technology is evolving from 4G to 5G. Compared to previous generations, 5G has the capability to implement latency-critical services, such as autonomous driving, real-time AI on handheld devices and remote drone control. Multi-access Edge Computing is one of the key technologies of 5G in guaranteeing ultra-low latency aimed to support latency critical services by distributing centralized computing resources to networks edges closer to users. However, due to its high granularity of computing resources, Multi-access Edge Computing has an architectural vulnerability in that it can lead to the overloading of regional computing resources, a phenomenon called regional traffic explosion. This paper proposes an improved communication architecture called Hybrid Cloud Computing, which combines the advantages of both Centralized Cloud Computing and Multi-access Edge Computing. The performance of the proposed network architecture is evaluated by utilizing a discrete-event simulation model. Finally, the results, advantages, and disadvantages of various network architectures are discussed.

FDIPP: False Data Injection Prevention Protocol for Smart Grid Distribution Systems.

In this paper, a false data injection prevention protocol (FDIPP) for smart grid distribution systems is proposed. The protocol is designed to work over a novel hierarchical communication network architecture that matches the distribution system hierarchy and its vast number of entities. The proposed protocol guarantees both system and data integrity via preventing packet injection, duplication, alteration, and rogue node access. Therefore, it prevents service disruption or damaging power network assets due to drawing the wrong conclusions about the current operating status of the power grid. Moreover, the impact of the FDIPP protocol on communication network performance is studied using intensive computer simulations. The simulation study shows that the proposed communication architecture is scalable and meets the packet delay requirements of inter-substation communication as mandated by IEC 61850-90-1 with a minimal packet loss while the security overhead of FDIPP is taken into account.