Operation Of Communication Network Research Articles

Метод децентралізованого управління мережевими ресурсами інформаційно-комунікаційних мереж

The paper presents a theoretical description of the proposed method of synthesis of wireless information and communication networks by clustering nodes and the allocation of the main elements of functioning: cluster controllers, nodes-gateways and clustering nodes to ensure a reduction of service traffic in solving problems of improving the quality of service and functioning of mobile networks. To synthesize the network based on the analysis, the k-means algorithm was chosen, based on its simplicity of implementation and a pre-known number of network clusters, on which it is necessary to distribute (cluster) nodes. The main metric used in the clustering and distribution of wireless information and communication network on the cluster zone chosen metric (Euclidean) distance between network nodes. During the initialization of the synthesized network, the volume of service traffic increases (by 10–12 %) due to the allocation of service information to determine the main structural elements of the network (cluster controllers, gateway nodes, node clustering, and the like). It is shown that the application of the method provides a significant reduction in service traffic compared to the known methods of network resources management during the actual transmission of information, and the gain of the advantage depends on the number of cluster zones on which the information and communication network is distributed. The proposed method of synthesis should be used to ensure high-quality and reliable operation of wireless information and communication networks, including global/local mobile networks, in conditions of limited network resources and missing or destroyed network infrastructure.

Cascading risk assessment in power-communication interdependent networks

With the expansion of power system scale, more and more network systems are interconnected to form a huge interdependent network. The most notable of these is the power-communication interdependent network. Modern power systems rely heavily on being controlled via communication networks; in reverse, power supply is the foundation of maintaining the normal operation of communication network. In such an interdependent network, a failure in one layer will not only disrupt its own stability, but may also cause a cascading failure between multiple layers. Therefore, developing an advanced method that can assess the cascading risk in power-communication interdependent network is essential. In this paper, an improved Complex Network model for power-communication interdependent network risk assessment is proposed. Firstly, a model of power system coupled with communication network is developed. Then data exchange rules which is improved from the existing ”point-wise” interdependent model are introduced. In addition, the interactions between the power system and communication network are provided. The simulation results demonstrate that the proposed method is effective for a power-communication interdependent network cascading risk assessment.

Time-Space Domain Availability Analysis Under Reliability Impairments

Availability and reliability are two essential metrics for the design, deployment, and operation of future ultra-reliable low latency communication (URLLC) networks. Despite a vast amount of research efforts toward URLLC, very little attention has been made on the ultra-reliable communication (URC) aspect of URLLC from a dependability perspective. As an effort toward achieving anytime and anywhere communication, this letter consolidates a dependability theory-based availability concept for individual users by taking into account reliability impairments that affect URC in both spatial and temporal domains . To this end, we perform per-user availability analysis by considering channel status and user mobility patterns in a Poisson Voronoi network.

Enhancing Cyber Security in Power Sector using Machine Learning

Nowadays, our lives have become very much dependent on the power systems, whether it is in home or in offices or anywhere. Any failure in the power systems can bring our lives to a halt. To ensure no power fault, a continuous and remote monitoring, control and automation are needed. The implementation of constraints increases the efficiency of the power systems. But, to put monitoring, control and automation into practice we need network, and with this come the threat of cyber-attacks. With more open standard-based communication network, the automated power systems have become the target of the cyber-attacks. By exploiting the cyber components in networks, critical cyber components can be manipulated. Intruders can tamper the communication links by injecting false or modified data. To come up with security measures against these attacks, vulnerabilities of the power systems are being assessed to analyze the impacts of the cyber-attacks. Several techniques have been implemented so far to make the power systems less prone to threats. In this paper, technology like Machine Learning is used as anomaly discriminator and to provide security to the power system against the cyber threats.

Evaluation of Efficiency of Random Multiple Access to ALOHA Type Environment with Voice Connections, Transfer of Service Commands, Text Messages and Multimedia Files in Destructive Impact Conditions

Assessing the security of digital radio networks in destructive impact conditions is an important task. However, such an assessment for random multiple access to the ALOHA-type environment in digital radio networks was not carried out. The paper presents an analytical model of random multiple access for the environment of digital radio networks of the ALOHA type in destructive impact conditions. In this model, acomplex measure, including the probability of a successful voice connection, the transfer of a service command, a text message or a multimedia file, the degree of filling and the degree of overflow of digital radio network data packets, serves as the resultant indicator for evaluating the effectiveness of random multiple media access. The new complex indicator of the probability of a successful voice connection, the transfer of a service command, a text message or a multimedia file takes into account the known probabilities of successful delivery of data packets, creation of a collision and a free channel, as well as new average transmission times for a sequence of data packets and a collision formed during such transmission. New indicators are the degree of filling and the degree of overflow of digital radio communications network data packets. They determine in saturated and supersaturated data networks of such a network how close (far) to maximum is the probability value of a successful voice connection, transmission of a service command, test message or multimedia file. The model takes into account the potential destructive effects of the attacker by refining the analytical expressions for the known probabilistic and new temporal characteristics. First, a quantitative relationship between the probability of a successful voice connection, the transfer of a service command, a text message or a multimedia file and the average duration of a data channel collisions is established./ Secondly, for guaranteed disabling a digital radio network with random multiple access to the medium ALOHA type attacker must constantly carry out a destructive impact. The results are applied in design of digital radio communications networks operating under destructive impacts, as well as in development of automatic systems for optimizing the operation of digital radio communications networks and protecting them from such impacts.

Delay-Dependent Stability Analysis of Network-Based Load Frequency Control of One and Two Area Power System with Time-Varying Delays

Network-based load frequency control (LFC) requires data transmission from the plant site to the control center and control center to the plant site. Communication delays resulting from an open communication network impart time-varying nature to network delay. This time-varying delay may debase the dynamic performance or instability of the LFC systems. Stability of the LFC system is investigated by Lyapunov–Krasovskii functional (LKF) analysis and linear matrix inequalities (LMIs) techniques. In this paper, a less conservative delay-dependent stability criterion is derived for the time-delay system by proper constructing of LKF and imposing tighter bounding of integral terms on time-derivative of LKF. Delay margin is obtained by solving proposed stability criterion for a time-delay LFC system equipped with a proportional-integral controller. The adequacy of the proposed result is confirmed using simulation studies.

Research on Key Elements of Safety Problems in Power Automation Communication Network

This paper briefly introduces the power communication system, expounds the power communication security protection technology, analyzes the security problems existing in the automation communication network, and conducts in-depth research and analysis on the security of the power automation communication network, hoping to secure the power automation communication network. Rationally utilizes the power automation communication network technology, improves the operation safety and stability of the power automation communication network, better meets the needs of the continuous and stable operation of the power automation communication network.

Simulations for Resource-Allocation Protocol Optimization for MIL-STD-188-186 over a UHF SATCOM Network

A simple simulation tool was previously developed to simulate the operation and performance of demand-assigned communication networks having time-varying data traffic patterns. Such networks use protocols to increase or decrease the resources allocated to a network node as the resource needs at that node change. These resource-allocation protocols have parameters such as numerical thresholds for requesting or releasing resources. The additional simulator development and execution described herein allows a comparison of performance metrics that result when using the existing MIL-STD-188-186 protocol versus using a proposed alternative protocol. The network behavior revealed by the simulation results also allows examining network performance trade-offs as values for the protocol parameters are adjusted. Although commercially available simulation tools could be used for these simulations, such tools are often expensive and sometimes complicated to adapt to new and not yet standardized protocols. The simple simulation tool that was previously developed is described in an earlier paper and is programmed as an Excel spreadsheet. It has now been adapted to allow comparing an existing resource-allocation protocol versus a proposed protocol for MIL-STD-188-186. The simulator allows examination of performance metrics such as the average number of assigned time slots per frame assigned to a transmitting node that has a specified message generation rate, the percentage of generated messages that are discarded prior to transmission due to being queued for an excessive time, and a histogram showing the percentage of messages transmitted with each possible message delivery time.

Modeling of Decision-making Processes to Ensure Sustainable Operation of Multiservice Communication Network

This paper shows the modeling of decision-making processes to ensure stable operation of multiservice communication networks (MCNs) using the mathematical apparatus of fuzzy logic models. A classification of the main factors affecting the stability of an MCN is given. The main factors affecting the structural stability of MCNs are external factors, internal factors, energy factors, and maintenance factors. A decision-making strategy (DM) was chosen. The main factors that affect the stability of the functioning of an MCN are characterized by heterogeneity. Therefore, the task of the DM to ensure stability of the functioning of the MCN was reduced to producing a sequential solution of the following interrelated tasks: identification of the MCN by a systematic analysis of the main factors affecting the stability of the MCN, ranking the states of the MCN, and definition of the decision-making criteria. The first point is implemented by setting up a complex model of the MCN based on integration of the principles of fuzzy set theory (FST). A promising method for choosing a rational alternative is the method of non-dominated alternatives (MNDA), based on the aggregation of fuzzy information to characterize the relationship between the alternatives according to certain criteria.

Проблемы оптимизации коммуникационных процессов в организации

The problems of information interaction of the company’s employees in the system of professional activity by means of communication are discussed in the article. Empirically established networks of communicative interaction and their differences from formal communication channels are mentioned in the article. The processes of dissemination of information for various types of communication networks are discussed in the article, the influence of strength and proximity of connections on the process of dissemination of information is analyzed. The impact of internal organizational interactions on the dissemination of information in closed and open communication networks are shown. An analysis of the communication network of a real organization are presented.

Wireless Networks Design in the Era of Deep Learning: Model-Based, AI-Based, or Both?

This paper deals with the use of emerging deep learning techniques in future wireless communication networks. It will be shown that the data-driven approaches should not replace, but rather complement, traditional design techniques based on mathematical models. Extensive motivation is given for why deep learning based on artificial neural networks will be an indispensable tool for the design and operation of future wireless communication networks, and our vision of how artificial neural networks should be integrated into the architecture of future wireless communication networks is presented. A thorough description of deep learning methodologies is provided, starting with the general machine learning paradigm, followed by a more in-depth discussion about deep learning and artificial neural networks, covering the most widely used artificial neural network architectures and their training methods. Deep learning will also be connected to other major learning frameworks, such as reinforcement learning and transfer learning. A thorough survey of the literature on deep learning for wireless communication networks is provided, followed by a detailed description of several novel case studies wherein the use of deep learning proves extremely useful for network design. For each case study, it will be shown how the use of (even approximate) mathematical models can significantly reduce the amount of live data that needs to be acquired/measured to implement the data-driven approaches. Finally, concluding remarks describe those that, in our opinion, are the major directions for future research in this field.

Ideas of the cosmism philosophy natural-scientific direction within media space and social-economic space

The article examines the influence of cosmism ideology and its orientation at principles of total interconnection, unity, obligatory coordination of human activity with the principle of world integrity on the formation of media space and socio-economic space of the information society. It displays that inwardness within the formation of humanity unity has been emphasised by the cosmism representatives Vladimir Solovyov, Nikolai Fedorov, Nikolai Berdyaev, Konstantin Tsiolkovsky, Vladimir Vernadsky, Edouard Le Roy, Pierre Teilhard de Chardin who manifested the world view position considering human, their past, present, and future through the lens of correlation with space. The research distinguishes the crucial role of cosmism ideology in development of modern media culture. It highlights the fact that, within the information society where formation of network communication systems provides the opportunity to shape global interaction systems enabling integrity of world culture or any national culture, priorities of cooperation and mutual aid ought to become dominant for mass media activity regardless of the civilisations, nations, regions, communities they represent. Policy in the sphere of media culture must be directed at the operation of communication network in the interchange mode, prevention of the situation when demassification of mass media may lead to localising, closing cultures of certain ethnic or religious groups.

Diskurs o nasilju prema ženama u srpskim onlajn medijima - dominantne komunikacijske strategije

This research aims to identify dominant communication strategies which are being used by the media to shape the topic of violence against women in Serbia. The media discourse on violence against women is the subject of this investigation, and it is located within: (1) media articles published in online editions of daily newspapers, (2) supplementary media text such as readers' comments on online news-portals and (3) post and comments on the Twitter social network (tweets). The first part of the research systematizes the main characteristics of media reporting on violence against women in Serbia that was present within last five years, which is accompanied by a review of relevant literature. The second part of the article presents the empirical findings on the conducted research which is based on an adequate sample which covers the first two months of the year 2019. The research hypothesis - which states that there is a difference between the discourse concepts utilized by traditional and social media when it comes to the subject of violence against women, as social media content is created outside of the classical editorial bounds - was tested using the discourse analysis and content analysis methods. The research specifically concentrates on verbal violence, and in that sense the research exemplifies how the recent phenomenon of open social network communication, which promotes the freedom of speech, produces the kind of communication that correlates with the misogynistic discourse that is embedded within a particular society. The following communication strategies were identified: the promotion and legitimization of misogyny as a form of public discourse; astroturfing; condemnation of misogyny as a form of public discourse; Ad hominem, and the political instrumentalization of the topic of violence against women.

COMPREHENSION OF WORLD'S WHOLENESS IN COSMISM PARADIGM

obligatory coordination of human activity with the principle of world integrity on the formation of media space and social space of the information society. It displays that inwardness within the formation of humanity unity has been emphasised by the cosmism representatives Vladimir Solovyov, Nikolai Fedorov, Nikolai Berdyaev, Konstantin Tsiolkovsky, Vladimir Vernadsky, Edouard Le Roy, Pierre Teilhard de Chardin who manifested the world view position considering human, their past, present, and future through the lens of correlation with space. Aim and tasks.The research distinguishes the crucial role of cosmism ideology in development of modern media culture. Reserch results. It highlights the fact that, within the information society where formation of network communication systems provides the opportunity to shape global interaction systems enabling integrity of world culture or any national culture, priorities of cooperation and mutual aid ought to become dominant for mass media activity regardless of the civilisations, nations, regions, communities they represent. Policy in the sphere of media culture must be directed at the operation of communication network in the interchange mode, prevention of the situation when demassification of mass media may lead to localising, closing cultures of certain ethnic or religious groups. Conclusions. Since mass media are intermediaries between state and society, power and human, cosmism ideas directed at cosmic prospects of humanity development, recognition of its mission obtain particular topicality when states conduct their policies in the sphere of media culture.

Impact of cyber dependencies in critical infrastructures: The reliability of grid splitting in power systems

The growing presence of cyber interdependencies in critical infrastructures can be exemplified by grid splitting, which is an application in power system stability and control dependent on communication services. It involves the controlled separation of a power system into islands in reaction to an imminent instability. Communication is necessary for gathering system-wide synchronized measurements for state estimation as well as for the dispatch of line switch-opening signals. However, grid splitting may become ineffective due to a degradation in communication, which is accrued by the use of non-dedicated, open communication networks. To address this issue, this article aims to quantify the reliability of grid splitting under degraded communication conditions. A simulation framework is developed that allows the integration of a transient electrical model and a stochastic communication delay model that captures the effects of congestion and traffic uncertainty. The application to the IEEE 39-Bus Test System shows that the reliability of grid splitting is reduced under the influence of degraded communication leading to increased time delays. Furthermore, the results identify a critical transition range in the grid splitting reliability for a very narrow range of external interfering traffic and network data rate. Finally, the interdependency of the electric and the communication network is quantified by the expected efficiency of the communication network subject to degraded communication following the grid splitting action. The decrease in the expected communication efficiency under degraded communication is driven by increased congestion levels and by failures of electrical and co-located communication nodes and is related to the critical transition range for reliability. The developed methodology allows identifying the communication requirements for a reliable grid splitting execution under traffic uncertainty and congestion.

Control and Monitoring of Electrical Variables of a Level Process using Modbus RTU-TCP/IP Industrial Communication

Background/Objectives: To develop an open protocol industrial communication network that allows the supervision, control and data acquisition of a frequency converter and an energy meter, which are connected to a pumping and level control system; this process will be carried out from a local, remote control - Human Machine Interface (HMI) and from the web, using Modbus RTU - TCP/IP. Methods: The implementation and configuration of equipment and devices of the Communication Network was carried out according to the three main layers that make up an Industrial OSI system, such as: the two-tier environment and connectivity in TCP/IP as well as in the Scada System RTU, controllers, meters, converters and field elements; the Configuration and Linking stage, both in TCP and serial and finally for the Application stage for both the Scada system and for the HMI. Findings: The configuration of the devices in TCP/IP used a 24 mask, while in RTU the identifier used was Id 15; the PC_System for the Scada System, the Delta display for the HMI, the PLC S7-1200 for programming the control system, as well as the Sentron Pac 3200 energy meter, monitor and control variables such as line and motor frequency, voltages and currents between lines, power and energy consumption of the industrial system and at the same time it will be possible to generate a record (Web, Server), of data in an Excel format, from any electronic device with internet access, entering through the IP address of the PLC previously configured with a user name and password that allows total access to the readings registered by the PLC. Applications/Improvements: In supervision, control and data acquisition systems of industrial processes of any type of variable, with controllers and field devices, both with TCP and RTU connectivity, of multiple brands of recognition or not in the market, improving the control and monitoring in real time, for the analysis, diagnosis and decision making, both local and remote, by maintenance, operation and management personnel. Keywords: Frequency Inverter, Human Machine Interface (HMI), Modbus TCP/RTU, Sentron PAC 3200, Web Server

Stability Robustness for Secondary Voltage Control in Autonomous Microgrids With Consideration of Communication Delays

The future extensive usage of open communication networks for secondary voltage control in autonomous microgrids (MGs) inherently introduce time delays, which would degrade the system performance or even cause instability in the worst case. However, existing literatures have largely ignored these communication delays between the microgrid central controller and primary local controllers. To fill the knowledge gap, this paper proposes an analytical method to determine the stability robustness of secondary voltage control in MGs by taking into account the communication latency effect. Based on static output feedback, a closed loop small-signal model of an MG installed with proportional-integral secondary voltage controllers is first derived. Delay-dependent criteria are then formulated to detect the stability posture of MG system by tracing critical eigenvalues and cluster treatment of characteristic roots, in the forms of delay margin for a single delay and stability tableau over the delay domain for multiple delays, respectively. By a series of trial declarations, the qualitative impact of secondary controller gains on system stability regions against uncertain delays is investigated, from which it can be observed that generally the increase of integral gains would yield to a less delay-dependent stability of control system and the results can be utilized to guide the controller design for a compromise between the dynamic performance and stability robustness. The effectiveness of the proposed methodology is verified by a simulation study.

Optimal orchestration of virtual network functions

The emergence of Network Functions Virtualization (NFV) is bringing a set of novel algorithmic challenges in the operation of communication networks. NFV introduces volatility in the management of network functions, which can be dynamically orchestrated, i.e., placed, resized, etc. Virtual Network Functions (VNFs) can belong to VNF chains, where nodes in a chain can serve multiple demands coming from the network edges. In this paper, we formally define the VNF placement and routing (VNF-PR) problem, proposing a versatile linear programming formulation that is able to accommodate specific features and constraints of NFV infrastructures, and that is substantially different from existing virtual network embedding formulations in the state of the art. We also design a math-heuristic able to scale with multiple objectives and large instances. By extensive simulations, we draw conclusions on the trade-off achievable between classical traffic engineering (TE) and NFV infrastructure efficiency goals, evaluating both Internet access and Virtual Private Network (VPN) demands. We do also quantitatively compare the performance of our VNF-PR heuristic with the classical Virtual Network Embedding (VNE) approach proposed for NFV orchestration, showing the computational differences, and how our approach can provide a more stable and closer-to-optimum solution.

Process Analytical Technology for Advanced Process Control in Biologics Manufacturing with the Aid of Macroscopic Kinetic Modeling.

Productivity improvements of mammalian cell culture in the production of recombinant proteins have been made by optimizing cell lines, media, and process operation. This led to enhanced titers and process robustness without increasing the cost of the upstream processing (USP); however, a downstream bottleneck remains. In terms of process control improvement, the process analytical technology (PAT) initiative, initiated by the American Food and Drug Administration (FDA), aims to measure, analyze, monitor, and ultimately control all important attributes of a bioprocess. Especially, spectroscopic methods such as Raman or near-infrared spectroscopy enable one to meet these analytical requirements, preferably in-situ. In combination with chemometric techniques like partial least square (PLS) or principal component analysis (PCA), it is possible to generate soft sensors, which estimate process variables based on process and measurement models for the enhanced control of bioprocesses. Macroscopic kinetic models can be used to simulate cell metabolism. These models are able to enhance the process understanding by predicting the dynamic of cells during cultivation. In this article, in-situ turbidity (transmission, 880 nm) and ex-situ Raman spectroscopy (785 nm) measurements are combined with an offline macroscopic Monod kinetic model in order to predict substrate concentrations. Experimental data of Chinese hamster ovary cultivations in bioreactors show a sufficiently linear correlation (R2 ≥ 0.97) between turbidity and total cell concentration. PLS regression of Raman spectra generates a prediction model, which was validated via offline viable cell concentration measurement (RMSE ≤ 13.82, R2 ≥ 0.92). Based on these measurements, the macroscopic Monod model can be used to determine different process attributes, e.g., glucose concentration. In consequence, it is possible to approximately calculate (R2 ≥ 0.96) glucose concentration based on online cell concentration measurements using turbidity or Raman spectroscopy. Future approaches will use these online substrate concentration measurements with turbidity and Raman measurements, in combination with the kinetic model, in order to control the bioprocess in terms of feeding strategies, by employing an open platform communication (OPC) network—either in fed-batch or perfusion mode, integrated into a continuous operation of upstream and downstream.

Design and Implementation of Carrier Aggregation in LTE—An Air-Interface Analyzer

Focusing on difficulties in communication networks test and optimization since some key technologies like carrier aggregation applied in communication networks, a LTE-An air-interface analyzer design scheme was proposed, which supports 3GPP R10/11 protocol standards and carrier aggregation. Firstly, the physical and logical architecture of LTE-A air-interface analyzer was introduced, and the relationship between them, the function of each module in them was illustrated. The application of the scheme can accelerate the commercialization of carrier aggregation in communication network, speed up the network deployment process and shorten the network construction cycle, and it will play an indispensable role in communication network operation and maintenance.