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This paper presents a time-dependent reliability analysis created for a critical energy infrastructure use case, which consists of an interconnected urban power grid and a communication network. By utilizing expert knowledge from the energy and communication sectors and integrating the renewal theory of multi-component systems, a representative reliability model of this interconnected energy infrastructure, based on real network located in the Czech Republic, is established. This model assumes reparable and non-reparable components and captures the topology of the interconnected infrastructure and reliability characteristics of both the power grid and the communication network. Moreover, a time-dependent reliability assessment of the interconnected system is provided. One of the significant outputs of this research is the identification of the critical components of the interconnected network and their interdependencies by the directed acyclic graph. Numerical results indicate that the original design has an unacceptable large unavailability. Thus, to improve the reliability of the interconnected system, a slightly modified design, in which only a limited number of components in the system are modified to keep the additional costs of the improved design limited, is proposed. Consequently, numerical results indicate reducing the unavailability of the improved interconnected system in comparison with the initial reliability design. The proposed unavailability exploration strategy is general and can bring a valuable reliability improvement in the power and communication sectors. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive overview of the microgrid (MG) concept, including its definitions, challenges, advantages, components, structures, communication systems, and control methods, focusing on low-bandwidth (LB), wireless (WL), and wired control approaches. Generally, an MG is a small-scale power grid comprising local/common loads, energy storage devices, and distributed energy resources (DERs), operating in both islanded and grid-tied modes. MGs are instrumental to current and future electricity network development, such as a smart grid, as they can offer numerous benefits, such as enhanced network stability and reliability, increased efficiency, an increased integration of clean and renewable energies into the system, enhanced power quality, and so forth, to the increasingly growing and complicated power systems. By considering several objectives in both islanded and grid-tied modes, the development of efficient control systems for different kinds of MGs has been investigated in recent years. Among these control methods, LB communication (LBcom)-based control methods have attracted much attention due to their low expenses, recent developments, and high stability. This paper aims to shed some light on different aspects, a literature review, and research gaps of MGs, especially in the field of their control layers, concentrating on LBcom-based control methods. [ABSTRACT FROM AUTHOR]

Battlefield of Things (BoT) is a modern defense network that connects smart military devices to strategic networks. Cybersecurity plays a vital role in maintaining the security of BoT networks and provides encrypted communication networks with combat devices on an end-to-end or peer-to-peer basis. This paper proposes approaches to BoT networks that operate on a three-tier architecture, starting with an application and service layer, a network and cybersecurity layer, and finally, a battlefield layer; implements CNN-YOLO-based target detection; and also formulates information security policies, privacy, and IT laws to maintain algorithmic data access and authorization. It connects a battlefield combat equipment network to a command data center's ground base station wireless, Bluetooth, sensor, radio, and ethernet cable. This paper analyzes prior Internet of Things (IoT) device attack strategies by collecting data sets of IoT security breaches from external sources. How the system security works, what breach techniques an attacker can use, how to avoid these, and how our systems can be strengthened to protect us from future attacks are discussed in detail. [ABSTRACT FROM AUTHOR]

The packet loss during transmission of load control commands can lead to regulation errors in the smart grid and increase the cost of utility agencies due to the purchase of additional automatic generation control (AGC) services. In this paper, a two-layer cooperative communication network between the utility company and relays is presented. The utility company rents the relay to assist with the downlink transmission to improve the reliability of communication and reduce the data transmission cost due to packet loss. Furthermore, the uncertainty of channel gain is considered, and a two-tier game model is established. A distributed robust power control algorithm based on the continuous convex approximation method is proposed to obtain the optimal relay power allocation and price. Through the simulation analysis of the proposed scheme and the two comparison schemes, the cost of the utility company was reduced by 6% and 21%, and the standard deviation of income value between the relays was reduced by 40% and 48%, respectively. [ABSTRACT FROM AUTHOR]

Modern communication networks and digital control techniques are used in a smart grid. The first step is to classify the features of several communication networks and conduct a comparative investigation of the communication networks applicable to the smart grid. The integration of distributed generation has significantly increased as the global energy demand rises, and sustainable energy for electric vehicles and renewable energies worldwide are being pursued. Additional explanations for this surge include environmental concerns, the reforming of the power sector, and the advancing of small-scale electricity generation technologies. Smart monitoring and control of interconnected systems are required to successfully integrate distributed generation into an existing conventional power system. Electric-vehicles-based smart grid technologies are capable of playing this part. Smart grids are crucial to avoid becoming locked in an obsolete energy infrastructure and to draw in new investment sources and build an effective and adaptable grid system. To achieve reliability and high-quality power systems, it is also necessary to apply intelligent grid technologies at the bulk power generation and transmission levels. This paper presents smart grid applicable communication networks and electric vehicles empowering distributed generation systems. Additionally, we address some constraints and challenges and make recommendations that will give proper guidelines for academicians and researchers to resolve the current issues. [ABSTRACT FROM AUTHOR]

Traditional substation automation system mostly uses single-chip computer as its internal core processor. This system not only has simple functions, but also has poor ability to deal with complex problems. In order to solve the above problems, a set of substation integrated automation control system based on DSP is developed in this paper. The system can monitor, measure, controls and coordinate the real-time operation status of substation equipment by analyzing and processing the collected data by DSP combined with communication and computer technology. Experiments and test results show that the automation system can better complete the functions of automatic monitoring and control of secondary equipment in substation, and significantly improves the efficiency of data transmission and sharing among electrical equipment in substation. [ABSTRACT FROM AUTHOR]

The minimum stretch spanning tree problem for a graph G is to find a spanning tree T of G such that the maximum distance in T between two adjacent vertices is minimized. The minimum value of this optimization problem gives rise to a graph invariant (G), called the tree-stretch of G. The problem has been proved NP-hard. In this paper we present a general approach to determine the exact values (G) for a series of typical graphs arising from communication networks, such as Hamming graphs and higher-dimensional grids (including hypercubes). [ABSTRACT FROM AUTHOR]

Digital closed-loop manufacturing technique, as a significant component of spiral bevel gear manufacturing system, has provided significant guarantee for improving the quantity and efficiency of spiral bevel gear tooth surfaces. The continuous fusion of digital closed-loop manufacturing and network technologies open a new route for the high-efficiency and high-precision manufacturing of spiral bevel gears. In order to realize the integrated operation and the information management in closed-loop manufacturing process of spiral bevel gears, this paper presents a universal networked closed-loop manufacturing model for spiral bevel gears by combining gear digital closed-loop manufacturing technologies and network technologies, which offers better support for the integrated design and machining of spiral bevel gear tooth surfaces. In this paper, the typical digital closed-loop manufacturing process of spiral bevel gears is deeply analyzed, and the framework of networked closed-loop manufacturing model is proposed. Furthermore, the integrated operation mechanism of networked closed-loop manufacturing model is established. On this basis, the key implementation mechanism of networked closed-loop manufacturing model such as the communication network construction, manufacturing information integration mechanism, and networked closed-loop manufacturing integration system development is elaborated respectively. Finally, an actual application experiment of spiral bevel gear pair networked closed-loop manufacturing is provided to demonstrate the feasibility and practicability of the proposed model. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) couplings between a motor drive and an adjacent communication network induce a considerable common-mode (CM) current in a communication cable, which has a serious impact on the performance of the communication network. In order to estimate the CM current, it is necessary to study the coupling mechanism between the motor drive and the communication network. In this paper, a commercial motor drive system with an RS485 communication circuit is used for analysis. The conducted and near-field coupling paths are analyzed and modeled. By integrating the models of coupling paths with the EMI models of the motor drive and the dc/dc converter, an estimation model of the CM current coupled to the communication cable is built. Furthermore, online measurement methods and numerical simulation are presented to extract the impedance parameters of the conducted and near-field coupling paths. The estimation model is validated by comparing the simulated currents with the measured currents in the two configurations. This model is applicable for estimating the CM current coupled to the communication cable in various configurations. [ABSTRACT FROM AUTHOR]

Power systems have been dramatically changing with cutting-edge information technologies. The new power system infrastructure has evolved and has been studied by many institutes and companies. Future power systems are bound up quietly with customer-side activities such as real-time pricing and distributed generators (DGs). To deploy those services on the power system, independent and hierarchical communication network architecture is proposed by information hiding and suppressing data exchange in this paper. The function of self-healing and resist attack will be easily implemented by this proposed network. This paper especially focuses on communication bandwidth and topology for power distribution areas as a backbone network for DGs. [ABSTRACT FROM AUTHOR]

Wu, W., 2018. Ship communication network intrusion signal identification based on Hidden Markov model. In: Liu, Z.L. and Mi, C. (eds.), Advances in Sustainable Port and Ocean Engineering. Journal of Coastal Research, Special Issue No. 83, pp. 868–871. Coconut Creek (Florida), I SSN 0749-0208. The current intrusion signal recognition method cannot effectively suppress the noise signal interference in the ship communication network environment, and is sensitive to the initial parameters, which results in low recognition accuracy. To address this problem, an identification method based on hidden Markov model is proposed for ship communication network intrusion signal in this paper. The eigenvalue of the collected network signal CSI (channel state information) is denoised and classified. The genetic algorithm is used to optimize the initial parameters of HMM and to solve the problem that the model is sensitive to the initial parameters. The classified signal is trained by hidden Markov model, and the network intrusion signal is identified by the trained HMM. Experimental results show that the maximum recognition accuracy of the proposed method is up to 97.58%, an d it has a lower error rate. [ABSTRACT FROM AUTHOR]

The conventional hierarchical control in an islanded microgrid (MG) does not consider the long time‐span dynamics of distributed storages (DSs). The main challenge in control of battery energy storage systems (BESSs) is different levels of stored energy in terms of state of charge (SoC). In power droop control, the energy of the BESSs with lower initial SoC is drained earlier, and their capacities become unachievable. Moreover, using droop control to balance the SoC of BESSs, deviates the steady state frequency and voltage from the nominal values. However, restoration of the MG frequency employing the conventional distributed secondary controllers disturbs SoC‐balancing, since SoC of BESSs are ignored. In this paper, a new distributed storage secondary controller (DSSC) scheme is designed for restoration of the voltage and frequency of a stand‐alone MG, and to provide power‐sharing and SoC‐balancing, using a distributed cooperative architecture. The cooperative DSs are controllable and exchange the information with neighbor DSs through a communication network. The unknown output power of the uncooperative renewable distributed generation (DG) is considered as external disturbance to the DSSC. The designed DSSC is robust against the variation of the communication configuration, and eliminates the necessity to communicate with uncontrollable DGs and loads. [ABSTRACT FROM AUTHOR]

Data collection is an important operation in a wireless sensor network (WSN). During data collection, the interference among nodes cannot be ignored. In a multi-hop WSN, one conventional way of defining interference neighbors is to prohibit a node from using the same time slot as those of its 1-hop and 2-hop neighbors. Recently, it is proved that for data collection in a WSN, since the set of communication nodes is limited and the transmission directions are toward the sink, a less strict set of interference neighbors can be defined [16] . The interference problem in a duty-cycle WSN (DC-WSN) with a corona structure is studied in [7] . In this paper, we solve the same problem by using the relaxed interference set defined in [16] . In particular, we give a complete classification of non-interference sets in 2-hop neighbors. We also propose a distributed 6-coloring algorithm. We prove a lower bound of six colors that every tree-based data collection algorithm requires in a dense DC-WSN, which proves our algorithm to be optimal. [ABSTRACT FROM AUTHOR]

In this paper, we exploit the cyber-physical testbed developed within the EU Project FACIES to analyze how monitor systems, typically used in Industrial Control Systems, may be prone to fail when facing cyber-attacks. Specifically, through several experimental trials, we test the poor ability of a Fault Diagnosis module to correctly manage cyber-attacks, which generally turn to be considered physical faults, forcing operators to perform erroneous countermeasures. To conclude, we outline how the presence of a cyber Intrusion Detection System improves the effectiveness and the reliability of the protection schema. The experimental validation has been carried out on an emulated water distribution system. [ABSTRACT FROM AUTHOR]

This paper addresses the event‐triggered consensus for heterogeneous multi‐agent systems (He‐MASs) via a distributed cooperative compensation control (D3C) strategy. The proposed D3C law involves two dynamics: (i) a pre‐given virtual leader, which specifies the synchronisation trajectory for whole He‐MASs; (ii) two intermediate compensation system, whose system state is broadcasted to neighbour agents through communication network for facilitating the consensus. To further reduce data exchanging frequency so as to alleviate communication burden, an exponential event‐trigger is employed to determine whether the current sampled data need to be broadcasted or suspended. By two concise algebraic Riccati inequalities and some supplement conditions, a sufficient collaborative design method is presented for obtaining the values of D3C gains and the thresholds of event‐trigger, while the Zeno phenomena is also excluded. The proposed strategy guarantees the consensus of He‐MASs and significantly reduces data exchanging amounts. Finally, some illustrative examples are given to validate effectiveness of the proposed results. [ABSTRACT FROM AUTHOR]

In communication networks, the volume of traffic, the number of connected devices and users continues to grow. As a result, the energy consumption generated by the communication infrastructure has become an important parameter that needs to be carefully considered and optimized both when designing the network and when operating it in real-time. In this paper, the methodology of calculation of complex parameters of energy consumption for transport telecommunication networks is proposed. Unlike the known techniques, the proposed methodology takes into account heterogeneity and multilayer networks. It also takes into account the energy consumption parameter during the downtime of the network equipment in the process of processing the service data blocks, which is quite an important task for improving the accuracy of energy consumption at the stage of implementing the energy-saving network. We also developed simulation software to estimate and manage the energy consumption of the optical transport network using the LabVIEW environment. This software tool allows telecommunication network designers to evaluate energy consumption, which allows them to choose the optimal solution for the desired projects. The use of electro-and acousto-optical devices for optical transport networks is analyzed. We recommended using electro-optical devices for optical modulators and acousto-optical devices for optical switches. The gain from using this combination of optical devices and the parameter of rij electro-optical coefficient and M2 acousto-optical quality parameter found in the paper is about 36.1% relative to the complex criterion of energy consumption. [ABSTRACT FROM AUTHOR]

In this paper, a tuned controller of variable reactors is developed to realize a reliable tieline reconnection of microgrids. It is very useful to solve the problem caused by a synchronization issue during the tieline reconnection, particularly the absence of a large-area communication network to cover all microgrids. The theoretical fundamental of this method is analyzed, based on which a set of tuning processes of the variable reactors' controller is derived. The feasibility and effectiveness of this tieline reconnection method with the tuned controller is analyzed and verified by simulations. This method can greatly improve the transient stability of a nonconventional grid, which consists of multiple microgrids, require the ability of frequent reliable reconnections, and limit system oscillation to less than 50%. The tieline reconnection controller can be easily integrated with power flow control into existing variable reactor devices at low cost. Moreover, the tuning process of the controller is simple and suitable for industrial applications. [ABSTRACT FROM AUTHOR]

Developments in the wind power industry have enabled a new generation of wind turbines with longer blades, taller towers, higher efficiency, and lower maintenance costs due to the maturity of related technologies. Nevertheless, wind turbines are still blind machines because the control center is responsible for managing and controlling individual wind turbines that are turned on or off according to demand for electricity. In this paper, we propose a communication network architecture for smart-wind power farms (Smart-WPFs). The proposed architecture is designed for wind turbines to communicate directly and share sensing data in order to maximize power generation, WPF availability, and turbine efficiency. We also designed a sensor data frame structure to carry sensing data from different wind turbine parts such as the rotor, transformer, nacelle, etc. The data frame includes a logical node ID (LNID), sensor node ID (SNID), sensor type (ST), and sensor data based on the International Electrotechnical Commission (IEC) 61400-25 standard. We present an analytical model that describes upstream traffic between the wind turbines and the control center. Using a queueing theory approach, the upstream traffic is evaluated in view of bandwidth utilization and average queuing delay. The performance of the proposed network architectures are evaluated by using analytical and simulation models. [ABSTRACT FROM AUTHOR]

Nowadays, large-scale wind power farms (WPFs) bring new challenges for both electric systems and communication networks. Communication networks are an essential part of WPFs because they provide real-time control and monitoring of wind turbines from a remote location (local control center). However, different wind turbine applications have different requirements in terms of data volume, latency, bandwidth, QoS, etc. This paper proposes a hierarchical communication network architecture that consist of a turbine area network (TAN), farm area network (FAN), and control area network (CAN) for offshore WPFs. The two types of offshore WPFs studied are small-scale WPFs close to the grid and medium-scale WPFs far from the grid. The wind turbines are modelled based on the logical nodes (LN) concepts of the IEC 61400-25 standard. To keep pace with current developments in wind turbine technology, the network design takes into account the extension of the LNs for both the wind turbine foundation and meteorological measurements. The proposed hierarchical communication network is based on Switched Ethernet. Servers at the control center are used to store and process the data received from the WPF. The network architecture is modelled and evaluated via OPNET. We investigated the end-to-end (ETE) delay for different WPF applications. The results are validated by comparing the amount of generated sensing data with that of received traffic at servers. The network performance is evaluated, analyzed and discussed in view of end-to-end (ETE) delay for different link bandwidths. [ABSTRACT FROM AUTHOR]

Abstract: Transmission and betweenness centrality are key concepts in communication networks theory. In this paper, a series of network descriptors based on betweenness centrality and transmission are proposed. Their extremal values as well as some graphs to which they correspond are given. [Copyright &y& Elsevier]

The paper presents a distributed algorithm that regulates the power outputs of multiple dispersed energy storage systems (DESS), which can be used to provide desirable services for power systems, such as renewable generation output smoothing and secondary control. The algorithm is based on the cooperative control principle of network control theory and it satisfies both the power balance requirement of power systems and the fair utilization among the DESS. The most distinct feature of the algorithm is that each DESS only requires the information from its neighbors through some local communication networks (CN), utilizing a virtual leader embedded in one or several DESS to receive a power command signal. In addition, to improve the robustness of the CN among DESS, two optimization models are formulated to design the so-called “N-1” redundant network, while considering both economic issues and convergence rate. These features enable the DESS under the algorithm to have both self-organizing and adaptive coordination properties under some adverse conditions. Simulation on the IEEE 123-bus distribution system validates the effectiveness of the proposed algorithm. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper we present a new framework to identify leaders in a Social Network Site using the Personalized PageRank vector. The methodology is based on the concept of Leadership group recently introduced by one of the authors. We show how to analyze the structure of the Leadership group as a function of a single parameter. Zachary’s network and a Facebook university network are used to illustrate the applicability of the model. [Copyright &y& Elsevier]

This paper presents a real-time simulation platform for smart grid applications. The developed platform is capable of simulating complex smart grid models with large numbers of high-speed switching devices at real time. Furthermore, an integrated approach is adopted to combine real-time simulations of communication systems and electric power systems together, which provides an effective approach to examine communication and distributed control related issues in smart grids. With the flexibility in representing a wide range of communication network configurations, the developed platform can also be used to evaluate reconfiguration strategies of communication networks in smart grids. A case study is demonstrated based on this platform. Simulation results validate the capability of the platform and also show the importance of the proposed comprehensive approach for the study of smart grids. [ABSTRACT FROM AUTHOR]

This paper presents the qualitative nature of communication network operations as abstraction of typical thermodynamic parameters (e.g., order parameter, temperature, and pressure). Specifically, statistical mechanics-inspired models of critical phenomena (e.g., phase transitions and size scaling) for heterogeneous packet transmission are developed in terms of multiple intensive parameters, namely, the external packet load on the network system and the packet transmission probabilities of heterogeneous packet types. Network phase diagrams are constructed based on these traffic parameters, and decision and control strategies are formulated for heterogeneous packet transmission in the network system. In this context, decision functions and control objectives are derived in closed forms, and the pertinent results of test and validation on a simulated network system are presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper discusses the communication and control co-design and co-simulation of wireless networked control systems. The interactions between the network and the control system are considered, and general networking and control co-design solutions are proposed for wireless control applications. The PiccSIM simulator for wireless control system simulation is used to study the effects of specific network protocol and control algorithms in practice. Packet loss models based on measurements of real industrial radio environments are incorporated into the simulator. This allows the realistic evaluation of the suitability of the network protocols for wireless control applications. A network quality of service measure is introduced, which gives a direct relationship between the network and control performances. Two simulation cases show the capabilities of PiccSIM for wireless control application research and development, where the co-design issues and solutions are demonstrated in detail. [Copyright &y& Elsevier]

Smart grids heavily depend on communication in order to coordinate the generation, distribution, and consumption of energy–even more so if distributed power plants based on renewable energies are taken into account. Given the variety of communication partners, a heterogeneous network infrastructure consisting of IP-based and suitable field-level networks is the most appropriate solution. This paper investigates such a two-tier infrastructure and possible field-level networks with particular attention to metering and supervisory control and data acquisition applications. For the problem of network integration, a combination of gateway and tunneling solutions is proposed which allows a semitransparent end-to-end connection between application servers and field nodes. The feasibility of the approach and implementation details are discussed at the example of powerline communication and IP-based networks investigated in the European research project on real-time energy management via powerlines and internet. Nevertheless, it is shown that the communication architecture is versatile enough to serve as a generic solution for smart grids. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a new method to classify the users of an SNS (Social Network Site) into groups is shown. The method is based on the PageRank algorithm. Competitivity groups are sets of nodes that compete among each other to gain PageRank via the personalization vector. Specific features of the SNSs (such as number of friends or activity of the users) can modify the ranking inside each Competitivity group. The concept of Leadership Group is also presented. Some numerical examples are shown. These concepts can also be applied to general complex networks. [ABSTRACT FROM AUTHOR]

As a key technology in smart grid, the wide-area measurement system (WAMS) will gradually become an important guarantee for security and stability of future power systems. This paper presents a quantified reliability evaluation method for the backbone communication network in WAMS and the overall WAMS from a hardware reliability viewpoint. The whole WAMS is modeled using a hierarchical structure. Markov modeling and state enumeration techniques are combined to perform the reliability evaluation. The WAMS in the IEEE 14-bus system is used as an example to demonstrate the application of the presented method in reliability assessment of overall WAMS. [ABSTRACT FROM AUTHOR]

This paper describes a simple and cost-effective method of frequency dissemination. In current digital communication networks, node clocks are hierarchically synchronized to the atomic master clock through fiber links. This synchronized network is used as an intermediate link for remote calibration services like the global positioning system common-view method. A prototype reference signal generator has been developed for recovering the communication clock signal and synthesizing a 10-MHz signal from it. The generator output frequency at the client site can be traced to coordinated universal time (UTC) National Metrology Institute of Japan (NMIJ) with some uncertainty, depending on the stability of the node clocks and the distance from the master clock. The stability performance of the generated reference signal has been tested at Okinawa-the farthest prefecture from Tokyo, where the master clock is located (baseline distance of 1500 km). The primary rate (1.544 MHz) for telecommunication services was chosen for the 10-MHz signal generation in the experiment. A sinusoidal phase fluctuation within a one-day period is dominantly observed. This fluctuation is mainly caused by fiber expansion and contraction due to normal daily temperature changes. It degrades the stability (Allan deviation) to the level of 5 × 10-13 τ = 40 000 s, which is almost half a day). However, the major part of the phase fluctuation can be canceled by averaging a full day's data. In this case, the Allan deviation becomes 1 ×-13 which is obtained at Okinawa over ten consecutive days of measurement. The worst average frequency offset relative to UTC (NMIJ) (one-day averaging) is -6.3 × 10-13. The results indicate that this method promises to be suitable for most applications, providing an uncertainty of less than 1 × 10-12 at an averaging time of one day. [ABSTRACT FROM AUTHOR]

Abstract: This paper is concerned with the design of improved active queue management (AQM) control schemes for time-delay systems taking into account explicitly the presence of delays in the controller design. A robust controller coping with uncertainties on the network parameters such as round-trip time and load variations is proposed. This is based on an appropriate robust reduction method for time-delay systems. A robust observer for time-delay systems is used to estimate online the average transmission window resulting in a robust output feedback stabilization scheme for AQM. The resulting control law is validated and tested firstly through numerical simulations and then pseudo-experimentally by network simulator (NS-2). [Copyright &y& Elsevier]

This paper presents an efficient cutset approach to compute the reliability of a large communication network having heterogeneous link capacities. The reliability measure has been defined as capacity related reliability (CRR). The proposed method, subset cut technique (SCT), requires the cutset information of the network. For each minimal cut Ci, and a given minimum band- width requirement Wm in, the method enumerates all nonredundant subset cut (SC), where each SC relates link capacities & minimum bandwidth requirements. Note that if all links in an SC fail, the capacity of the induced cut Ci will be less than Wm in. Given the failure probability of each link, and the nonredundant SC, any Boolean technique for generating mutually disjoint terms can be utilized to obtain a capacity related unreliability (CRU) of the net- work. Thus, the CRU for an (s, t) node pair is the probability that the network has a capacity of less than Wm in for the given node pair. Note that CRR = 1 - CRU. Two SCT algorithms are proposed: Algorithm-1, and Algorithm-2; and the suitability of using either algorithm is also discussed. Examples are given to illustrate the techniques. The time complexity, and the proof of correctness for the proposed algorithms are also included. It is shown empirically that the time complexity of generating the nonredundant SC of a network is polynomial in the order of the number of cuts of the network. The proposed SCT algorithms have been implemented in C. We have utilized the SCT to generate the CRR of some large communication networks with various Wm in values. [ABSTRACT FROM AUTHOR]

Communication networks have been characterized by high levels of service reliability. Links cuts, node interruptions, software errors or hardware failures, and transmission failures at various points can interrupt service for long periods of time. In communication networks, greater degrees of stability or less vulnerability is required. The vulnerability of communication network measures the resistance of the network to the disruption of operation after the failure of certain stations or communication links. If we think of a graph $G$ as modeling a network, many graph-theoretic parameters can be used to describe the stability of communication networks, including connectivity, integrity, and tenacity. We consider two graphs with the same connectivity, but with unequal orders of theirs largest components. Then these two graphs must be different in respect to stability. How can we measure that property? The idea behind the answer is the concept of integrity, which is different from connectivity. Total graphs constitute a large class of graphs. In this paper, we study the integrity of total graphs via some graph parameters. [ABSTRACT FROM AUTHOR]

A communication network management system takes the measurements of its state variables at specific instants of time, considering them constant in the interval between two consecutive measurements. Nevertheless, this assumption is not true, since these variables evolve in real time. Therefore, uncertainty is inherent in the processing of the measurements during the intervals so that they cannot be efficiently managed using crisp variables. In this paper, we face this problem by modeling the communications network as a type-V fuzzy graph, where both the nodes and the links are described with precision, but the cost of each link is modeled as a triangular fuzzy number. Different fuzzy cost allocation functions and fuzzy optimization strategies are described and applied to the search for the shortest path between two nodes. An experimental study has been conducted using two representative networks: the backbone network of Nippon Telegraph and Telephone Corporation (NTT) and the National Science Foundation's Network (NFSNET). In these networks, our fuzzy cost functions and strategies have been compared with the well-known crisp equivalents. The optimal search strategies are based on the proposed Fuzzy Dijkstra Algorithm (FDA), which is described deeply. The simulation results demonstrate that in all cases the fuzzy alternatives surpass or equal the crisp equivalents with statistically significant values. Specifically, the so-called Strategy 8 presents the best throughput, as it significantly exceeds the performance of all those evaluated, achieving a Global Mean Delivery Rate (GMDR) close to 1. [ABSTRACT FROM AUTHOR]

This paper primarily deals with the design of an Information and Control Technology (ICT) network for an advanced metering infrastructure (AMI) on the IEEE 34 node radial distribution network. The application is comprised of 330 smart meters deployed in the low voltage system and 33 data concentrators in the medium voltage system. A power line carrier (PLC) communication system design is developed and simulated in Network Simulator 3 (NS-3). The simulation result is validated by comparing the communication network performance with the minimum performance requirements for AMI. The network delay of a single data frame is calculated and compared with the simulation delay. The design methodology proposed in this article may be used for other smart grid applications. The secondary goal is to provide AMI network traffic based on the IEC Std. 61968 and a discussion on whether or not AMI could possibly be a source of big data on the future power grid. [ABSTRACT FROM AUTHOR]