Interconnected communication networks

Review of Medical Implant Communication System (MICS) band and network

Modern hospitals are beginning to adopt E-HEALTH as efficient complements to the traditional healthcare services. To support the E-HEALTH services, a locatable, radiation-free and high-capacity communication system is urgently needed in hospitals. Power line communication (PLC) system can use the ubiquitous power line network to power the light-emitting diode (LED) lights while serving as the backbone network for the indoor visible light communication (VLC) systems naturally. In this paper, an integrated broadband power line and visible light communication systems with OFDM modulation is proposed for the indoor hospital applications. This gives a brand-new solution to replace the conventional wireless communication systems in hospitals.

This paper focuses on cascading line failures in the transmission system of the power grid. Such a cascade may have a devastating effect not only on the power grid but also on the interconnected communication networks. Recent large-scale power outages demonstrated the limitations of epidemic- and percolation-based tools in modeling the cascade evolution. Hence, based on a linearized power flow model (that substantially differs from the classical packet flow models), we obtain results regarding the various properties of a cascade. Specifically, we consider performance metrics such as the the distance between failures, the length of the cascade, and the fraction of demand (load) satisfied after the cascade. We show, for example, that due to the unique properties of the model: (i) the distance between subsequent failures can be arbitrarily large and the cascade may be arbitrarily long, (ii) a large set of initial line failures may have a smaller effect than a failure of one of the lines in the set, and (iii) minor changes to the network parameters may have a significant impact. Moreover, we show that finding the set of lines whose removal has the most significant impact (under various metrics) is NP-Hard. Moreover, we develop a fast algorithm to recompute the flows at each step of the cascade. The results can provide insight into the design of smart grid measurement and control algorithms that can mitigate a cascade.

We propose a practical message-wise unequal error protection (UEP) scheme using low-density parity-check (LDPC) codes, where one or more special messages are more protected than other ordinary messages, which performs codeword flipping to separate the codewords of special and ordinary messages. To better distinguish the original and flipped codewords, the LDPC codes with all-odd degree check nodes are employed. The decoder performs message type detection and codeword flipping detection by tracking the number of unsatisfied check nodes in iterative decoding. We provide both finite-length and asymptotic performance analysis for the proposed coding scheme. Simulation results are provided to show that the proposed practical message-wise UEP schemes offer capacity-approaching protections to both types of messages as if only one type of message is transmitted.

While interconnected systems proliferate in nowadays computing and communications technology there are few reports investigating their security. In this paper, new efficient models are developed and evaluated for analyzing the security-related behavior of computing architectures and networks comprising complex interconnected communication systems adapted towards a generalized analysis. These models, based on Markov processes, allow calculation of critical security factors, related to intrusion detection, of such interconnected systems components and the evaluation of the associated security mechanisms. Although, at this step two interconnected systems are analyzed, the systematic model introduced allows for a generalized model of N interconnected systems. We herein show the principles of such an analysis. Security parameters calculation and Security mechanisms evaluation may support the risk analysis and the decision making process in resolving the trade-offs between security and quality of service characteristics corresponding to the complex interconnected computing and communication systems.

This paper is concerned with the microgrid communication systems and their impact on the microgrid control system. Regardless of the control structure, a microgrid cannot exist without a communication system. An efficient and reliable communication network ensures the possibility of implementing a secure, durable and cost-effective microgrid. The configuration of the communication network depends on many factors, like the structure of the microgrid, the control objectives, the implementation costs, the maintenance costs, etc. In the case of centralized control, all relevant data from the entire system is collected and processed in a single controller. The failure of a communication link in this central controller may cause the entire microgrid to fail. Therefore, the existence of a robust and reliable communication system is vital and the creation of redundant communication links is also recommended. The situation is different in the case of decentralized control, where communication is limited to local controllers, but this leads to limited performance, therefore it is preferable for such microgrids to have at least a very basic communication system composed of simple and inexpensive communication network. In the case of distributed control, each subsystem has its own local controller (LC) with the ability to communicate with other controllers for the purpose of exchanging information. Thus, the most advantageous communication network architecture is a hybrid one that consists of a combination of centralized and decentralized control methods.

Future power systems in terms of Cyber - Physical Energy Systems (CPES) apply the integration of IT and physical processes using local and wide area communication networks. The smart grid is a typical example of the application of CPES and poses additional challenges to the engineering as these networks consist of two components: the power system itself and an underlying communication network applied for transmitting monitoring and control information. Therefore, performance evaluations of CPES need to take into account both networks in detail in order to provide meaningful results. In this paper, we introduce our simulation environment INtegrated co-Simulation of Power and ICT systems for Real-time Evaluation (INSPIRE), which is based on the Hybrid Simulator Architecture [1] and capable of evaluating both power system and communication network within a co-simulation framework. Besides the simulator architecture, we detail our time synchronization approach, which is applied for interconnecting communication and power system simulation. Secondly, we present reference scenarios and configuration settings for the combined simulation system. Finally, we introduce the first performance evaluation carried out using INSPIRE, covering characteristics of the communication network and highlighting the retroactive effects on the power system using an exemplary control algorithm.

Performance analysis of coexistence of traditional communication system and emerging semantic communication system

Deep-ultraviolet (DUV) light communication can effectively resist solar noise and electromagnetic interference across complex electromagnetic scenarios. However, mobility is still a crucial issue that hinders its application. Here, we integrated visual-tracking features with DUV light communication systems, consequently proposing a mobile deep-ultraviolet light communication (MDUVLC) system under the transmission control protocol/Internet protocol (TCP/IP) scheme. The MDUVLC apparatus is finally employed on drones and land vehicles, with real-time video communication between these moving nodes experimentally demonstrated in sunlight. This apparatus can combine with other bidirectional communication systems to establish a complete mapping all-light communication network for seamless connectivity across different environments, in which all nodes are symmetric and decentralized.

The conventional power grid has gone into transition and converted into what is called "smart grid The smart grid helps to bring reliability, monitoring, controllability, and efficiency. It provides a bidirectional flow of energy and communication. The major element of the smart grid is the communication networks. The smart grid system is comprised of different types of smart devices and heterogeneous networks. These communication networks are prone to many kinds of attacks such as Distributed Denial of Service (DDoS), Man In The Middle (MITM) and replay attacks. As a result, the smart grid is becoming a major target for cybercriminals. In this paper, the vulnerabilities and security issues exist in the smart grid are presented. Finally, the solutions for mitigating the attacks are discussed. It provides an overview of security issues present in the communication system in the smart grid. With this paper, readers can gain more understanding of security issues present in the smart grid communication systems, networks, and devices.

Introduction While wireless communications standards may come and go with developments in the latest digital coding technology, or the liberation of new fragments of the electromagnetic spectrum, the common denominator among the various communications systems is the power amplifier. Over the last few decades, the transition from vacuum tubes and other forms of amplification to solid state devices has been almost complete, especially at power levels less than 1 kW. Nowadays, at the heart of the power amplifier, we find the power transistor. In the world of RF wireless communications, the base-stations and long range transmitters use silicon LDMOS (laterally-diffused MOS) high power transistors almost exclusively. In addition to modern cellular communication systems, LDMOS devices are also used in a wide range of applications requiring radio-frequency power amplification: HF, VHF, and UHF communications systems; pulsed radar; industrial, scientific and medical (ISM) applications; avionics; and most recently in WiMAX™ communication systems. The frequency range of these applications is from a few megahertz and up to 4 GHz. While LDMOS technology is pre-eminent in high-power RF and lower frequency microwave applications, a wide variety of compound (III–V) semiconductors are used as effective power amplification devices, especially for application frequencies above about 5 GHz, and also for lower power applications such as cellular handsets, Bluetooth™ and other wireless local area networks (WLANs), which generally demand output powers of about 1 watt or below.

Light Fidelity (Li-Fi) is an emerging optical wireless communication (owc) system that employ light-emitting diodes (LEDs) to acheive medium to high speed transmission using optical signals. Li Fi is a form of Visible light communication(VLC) technology i.e. lifi provides secure communication connectivity for under water communication,smart home, smart cities, classrooms and hospital,medicial equipment,traffic and vehicle communication. It strengthens security compared to modern radio-frequency (RF) communication systems. RF-based systems are sensitive to jamming, and the available spectrum is heavily occupied due to multiple devices operating on the same frequency band. This results in issues such as low data quality, collisions, and interference, particularly in indoor environments.In this work, a low-cost Li-Fi communication system is implemented to address these limitations while keeping the system affordable and simple. The proposed approach uses microcontrollers such as ESP8266 and ESP32 as the transmitter and receiver, respectively. At the transmitter side, text data are entered from a phone or laptop into the ESP8266 through a serial interface and transmitted using a laser diode.The laser diode is controlled via On-Off Keying (OOK) modulation, in which the light source alternates between ON and OFF states to represent binary data. By streamlining the encoding and decoding process, this method facilitates the receiver’s detection and interpretation of the transmitted text. At the receiver side, an ESP32 microcontroller is used to handle the received data, process it, and display the decoded text on an OLED screen. A high-sensitivity light dependent resistor (LDR) sensor module is used to sense the incoming light signal in real time, and threshold-based detection is applied to distinguish between logic levels. The system was tested indoors under normal lighting conditions, and successful text transmission was observed without noticeable interference during communication. The experimental result of Li-Fi demonstrate the high speed data transmission upto 100 Gbps.

Design of Digital Phase Shifters for Multipurpose Communication Systems aims to cover a new emerging need in designing digital phase shifters for modern communication systems. With the advancement of new generation mobile communication systems, directed beams save a substantial amount of RF-power, and improve the noise immunity. In this regard, beam-forming circuits, namely, digital phase shifters constitute essential parts the antenna arrays. Therefore, this book is devoted to design of digital phase shifters for various communications systems. In the good old days, phase shifter design requirements used to demand narrow bandwidth with no physical size constraints. Nowadays, they must be compact and suitable for Very Large Scale Integrated Circuits (VLSI) or Microwave Monolithic Integrated Circuit (MMIC) implementation with Wide Phase Range (WPR) and Wide Frequency Band (WFB). Since the 1980s, the author has been designing digital phase shifters for various applications. He started to work with loaded lines phase shifters, and then employed branch line couplers to achieve wider frequency bands. In order to reduce the physical size, he used a 3 element Symmetric LC ladder based T or PI configurations. In order to achieve broad frequency band with large phase range, usage of LC lattice structures is inevitable. Lately, the author designed phase shifters using both lowpass and highpass LC ladder and lattice based switched-structures, which are suitable for monolithic implementation. In the course of design, MOS transistors were employed as switching elements. This book includes several novel digital phase shifter topologies, which provides wide phase range and wideband operation. Technical topics discussed in the book include: • Basic Concept of Antenna Arrays • Concept of Digital Phase Bit • Scattering Parameters to analyze the electric performance of phase shifters • Transmission Lines as circuit elements to construct practical phase shifters • Loaded Line Digital Phase Shifters (DPS) • 180° - Lowpass Based T/PI Section DPS • 180° - Highpass Based T/PI Section DPS • 180° 3-Element LC T/PI Section DPS • 180° Wide Phase Range, Wide Frequency Band Symmetric Lattice Based DPS For each topology presented, explicit design equations are provided and programs to assess the electric performance of each topology is developed in a MatLab environment. It is expected that the reader will be self-sufficient to design and implement the digital phase shifters topologies presented in this book.

The subject of the research is the methods and schemes of user authentication in information and communication networks. The aim of the work is to develop a user authentication model in information and communication systems using the zero-watermarking method based on RGB images. Objectives: to examine the main issues arising during the integration of access control systems; to develop a user authentication model using zero-watermarking; to study potential characteristics and put forward proposals/recommendations for its application in authentication; to construct graphical schemes that illustrate processes and procedures. Methods used: modeling methods and formal description methods. Results achieved: an improved user authentication model based on the zero-watermarking algorithm has been proposed as an alternative to existing authentication schemes in information and communication systems; its potential characteristics have been studied, confirming the prospects of the development; graphical representations of processes and procedures have been constructed. Conclusions: in the course of the work, the main problems faced by owners of information and communication systems during the integration of authentication systems were briefly reviewed; an improved authentication model using zero-watermarking was proposed. The zero-watermarking method is based on RGB images employing K-means clustering and DWT, while a password is used as the second factor. Three operating modes are presented: registration, authentication, and modification of key authentication data. This model serves as an alternative to existing schemes and can potentially reduce the cost of authentication, lower Type I and Type II error rates compared to similar authentication schemes, and improve the convenience of authentication in information and communication systems. It also expands the range of authentication schemes available to system owners during integration.

The introduction of new technology in the wireless communication industry increases the number of frequency bands in the communication environment. Therefore, a communication system capable of functioning over several frequency bands, known as a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">multiband communication system</i> , is required. In addition, multiband communication systems support technology upgrades by smoothly bridging the migration from the existing technology to a newer technology. A multiband communication system can be developed with the help of two approaches. The first approach is a multiband communication system that contains multiple microwave circuits, with each circuit optimized for a single band; for example, a dual-band communication system has two low-pass filters and two power amplifiers. But this approach increases not only the size but also the cost of the system. In the second approach, rather than using a separate power amplifier and filter for each frequency band, a single power amplifier, filter, and other components are used that can support more than one frequency band. These circuits are known as <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">multiband microwave circuits</i> . Multiband circuits not only minimize size but also reduce the cost of designing the multiband communication system.