The impact of communication on microgrid control

Demands for very reliable and robust communications systems are becoming commonplace, and this is true for air-to-ground (AG) systems, which are seeing increased usage, particularly for unmanned aircraft. Available spectrum exists for AG communications systems in the L-band (960–1164 MHz). Two robust L-Band Digital Aeronautical Communication Systems (L-DACS) were recently defined, LDACS1 and LDACS2. The L-DACS1 scheme employs a fairly broadband (0.5 MHz) transmission using Cyclic-Prefix Orthogonal Frequency-Division Multiplexing (CP-OFDM) together with adaptive coding and modulation. In this paper we propose a new AG communication system based on OFDM-OQAM filter bank modulation, using features similar to those of the L-DACS1 physical layer, and show how better subcarrier filtering can improve spectrum efficiency in AG channels. Channel estimation (CE) in OFDM-OQAM systems must employ a pilot method completely different from classical pilot-based CP-OFDM systems, since in OFDM-OQAM the pilots should remove pilot subcarrier interference from neighboring subcarriers. We employ a low complexity pilot-based CE on the OFDM-OQAM signal, and show BER results for L-DACS1 and for comparable OFDM-OQAM based systems in an example AG channel. The AG channel we employ is one based upon a recent extensive measurement campaign. We also estimate channel throughput and mean square error (MSE) for these two systems, and show that for similar BER performance, both channel estimation and throughput of the new system are better than that for L-DACS1.

With the development of digital instrument and control technology for nuclear power plants in recent decades, communication networks have become an important part of safety digital control systems, which takes charge in data exchange between the various sub-systems, and extremely impact on the reliability and safety of the entire I&C system. Traditional communication systems where some special features, such as reliability, safety, real-time, certainty, and independence are not strictly required are various illustrated. However, how to implement a communication system in a safety I&C system is rarely stated in current research. In this research, a reliable safety communication system applied in nuclear power plants is designed and analyzed. The five key characteristics of nuclear safety communication networks are explained, followed by explanation of how to achieve these characteristics. The analysis and verification of the designed system are also stated in this paper, which contributes to proving that the designed nuclear safety communication system could applied in the nuclear power plants.

Underwater acoustic channels usually suffer from the extended multipath propagation which causes inter symbol interference (ISI). At the receiving end, serious ISI would result in the decrease of the reliability of underwater acoustic communication systems. In this paper, Turbo equalization is applied to increase the reliability of communication systems. The realization of the channel equalizer in Turbo equalization is the linear minimum mean-square error (MMSE) estimate. To avoid performance loss, Turbo equalization and factor graph are combined together which provides a full-window method. Moreover, a modified extrinsic information feedback mechanism of turbo equalization is proposed. The reliability of communication systems is further enhanced by using this mechanism. Simulation results show that the proposed algorithm performs well with low complexity. This demonstrates the potential of the suggested algorithm in practice.

Positive train control (PTC) provides a critical safety backup for train operations to protect against the consequences of human error. With the Rail Safety Improvement Act of 2008 mandating positive train control for most North American railroads, railroad community efforts are underway to develop an interoperable PTC communications system over a 220 MHz network. A robust, reliable, and interoperable communications system is one the most vital components to the success of the PTC technology. This paper presents the design and modeling of a 220 MHz interoperable PTC system. The paper introduces a communication protocol that is designed to efficiently meet PTC communications needs within the available 220 MHz spectrum. The paper also presents simulation system architecture for analyzing the performance of the 220 MHz PTC system. Extensive simulations are conducted to evaluate the system performance and validate the design.

As network centric operations (NCO) deploy in military missions on the land, sea and in the air, bandwidth demands dictate exploitation of available electromagnetic spectrum. This valuable warfighter resource must deliver timely information across various communication networks in the most efficient and reliable manner. Internet protocol version4/6 (IPv4/6) intends to achieve such bandwidth utilization but the more important question of latency and reliable information delivery stands paramount for swift and decisive actions. This bandwidth utilization comes to the warfighter in terms of available data rates and subsequent to that, information rates. Overall, the paper describes the major aspects desired in a reliable NCO communications system as well as the required element performances. This paper offers typical scenarios for various networked links, their associated data and information rates, expected latencies, and typical link closure distances. Analysis couples realistic example network formations to present a representative foundation for performance prediction, evaluation and measurement. This includes realistic constraints in representative environments producing analytical results suitable for communication system lay-downs. The paper concludes with system observations and a look to future efforts that would benefit the warfighter when completed.

Adaptive global coordination of local routing policies for communication networks

Li-Fi (light-fidelity) considers a new technology in the wireless communication domain that operates light for transmission free space; the end-user has employed Visible Light Communication based on Light Emitting Diodes. This study aims to investigate the performance of Li-Fi to transmit data like video and pictures using different data rates under atmospheric turbulence such as rain and dust that affect FSO, therefore it affects at end-user and verifies the reliability of the Visible Light Communication (VLC) system sending data at high-speed data transmission. The systems are simulated by Optisystem V 18; the proposed system is built as a VLC system linked with fiber optic and free space optic channels to transmit various video sizes and an image using data rates of about 100 Mbps and 600 Mbps, and 1 Gbps over a lengthy distance under different weather, System was estimated in phrases of bit error rate, quality factor, power of signal, signal to noise ratio, and variation in angles. Despite the harsh environmental conditions imposed on the communication network, VLC has proven its ability to transmit high-speed data transmission for user's requirement.

Development of Highly Reliable Power and Communication System for Essential Instruments Under Severe Accidents in NPP

HSR has been developed rapidly all over the world, which puts forward requirements for a reliable and efficient wireless communication system between the moving train and the ground. According to International Union of Railways (UIC) E-Train Project, the train-ground wireless communication services for HSR system mainly include the train control services, the train monitoring services, and the passenger services from/to Internet. The train control and monitoring services are special services for train needs and provided by train operators mainly using Global System for Mobile Communications-Railway (GSM-R), which is an international wireless communications standard for railway communication and applications. With the rapid growth of HSR services, GSM-R has been unable to support the broadband communication systems. Therefore, from GSM-R to long-term evolution for railway (LTE-R) is the essential trend to guarantee a reliable communication systems. By introducing and comparing the network architecture and key technologies of GSM-R and LTE-R system, this chapter discusses the development of the next-generation HSR broadband communication systems.

Recently, ultra-high frequency (UHF) radio frequency identification (RFID) technique has been studied for the application of internet of thing (IoT) sensor communication system whose recent requirements are very low power consumption, longer communication range, and robustness to interference channel. However, these communication systems easily affect by the fading or reflections at the receiver signal strength. In this paper, a new UHF RFID-based IoT sensor communication system is studied to overcome the interference and multipath fading by antenna nulling technology that can be made by beam forming control of electronically steerable parasitic array radiator (ESPAR) antenna instead of using patch antenna. In addition, the proposed electronically steerable antenna's localization of a passive RFID tag and a stationary reader is based on the direction of arrival (DoA) and angle of arrival (AoA). ESPAR antenna exhibits higher gain and proper radiation pattern. The work can be applied to the wireless electrocardiogram (ECG) monitoring system by providing better advantages such as higher accuracy, wider range, and longer battery life span. The antenna nulling is very good to enhance the signal-to-interference ratio (SIR) performance of the system. Thus, the proposed design is considered to be a reliable, robust, relatively long-distance, and low-power IoT sensor communication system.

Solving channel equalization problem in communication systems is based on adaptive ltering algorithms. Today,Mobile Agents (MAs) with Recurrent Neural Networks (RNNs) can be also adopted for e ective interferencereduction in modern wireless communication systems (WCSs). In this paper MAs with RNNs are proposed asnovel computing algorithms for reducing interferences in WCSs performing an adaptive channel equalization.The method to provide it is so called MAs-RNNs. We perform the implementation of this new paradigm forinterferences reduction. Simulations results and evaluations demonstrates the e ectiveness of this approach andas better transmission performance in wireless communication network can be achieved by using the MAs-RNNsbased adaptive ltering algorithm.Keywords: Wireless communication systems, Mobile Agents, Recurrent Neural Networks, interferences reduc-tion, channel equalization 1. INTRODUCTION New challenges in modern communication is to conceive highly reliable and fast communication system deprivedfrom problems caused by multipath fading in wireless channels. A very important problem in data commu-nications is channel equalization. i.e., the removal of interferences introduced by linear or nonlinear messagecorrupting mechanisms. Thus the originally transmitted symbols can be recovered correctly at the receiver.New techniques to provide the optimal detection under bad channel estimation and solving the channel equal-ization must be developed and evaluated. To achieve fast and reliable wireless digital communication, as forinter-symbol interference (ISI), studies must concern adaptive equalization to minimize the communication errors

With the development of power electronics technology and the promotion of changes from both the power supply side and the load side, distributed energy is increasingly being connected to the grid in the form of AC/DC hybrid micro-grid. The innovation will bring about a significant change on the network structure, new challenges to the design of the micro-grid control system, and also put forward new requirements for the simulation test method. Based on the control objects and target functions of different levels of the DC micro-grid control system, this paper proposes a typical design method of the DC micro-grid control system, and the corresponding performance indicators. Meanwhile, in order to solve the contradiction between simulation calculation time and equivalent modeling accuracy, this paper uses modular modeling design and simulation method to build three-level simulation models for components, devices and systems, and divides the grid-connected DC micro-grid system into control nodes in three categories, builds subsystems for corresponding simulation models and control function sub-modules, established closed-loop test platform based on RTDS, and then carried out hardware-in-loop test for micro-grid control system to verify the performances of the control strategy.

In the high-speed maglev transportation system, an efficient and reliable train ground communication system plays an important role in ensuring the safe operation of the train. And, the increasing demand for high-speed broadband services such as digital video services also puts forward higher requirements for wireless communication in high-speed transportation. The development of the fifth generation mobile communication (5G) is to meet the requirements of high reliability and super capacity of wireless communication system. However, the explosive growth of data, high-speed and low delay communication requirements have brought great challenges to the communication system. The organic integration of wireless communication and deep learning is expected to solve the technical problems of complex communication systems. Firstly, this paper describes the challenges of the 5G key technology - MIMO technology in channel estimation, beamforming and channel detection. Then it introduces a series of research on introducing deep learning into MIMO physical layer technology. The results show that deep learning is expected to solve the problems of MIMO technology.

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.

This paper presents a novel visual detection-based approach for predicting imminent blockages of wireless radio links in industrial ultra reliable low-latency communication (URLLC) systems. The solution is based on detecting the bounding box of the UE-object and deducing from the temporal behavior of the bounding box whether the object is about to be blocked by an obstacle. It is shown that such detection approach allows one to predict the blockage as the bounding box starts to become smaller much before the full blockage occurs. Simulation results indicate that the proposed visual blockage prediction scheme can significantly reduce the latency of URLLC networks by preventing packet errors due to blockage and the associated reduction in link quality. In macro cell scenarios, the latency reduction is as much as 5 ms. In addition, we also show that the detection range of the proposed solution is sufficient for most industrial applications; with a 4K camera, reasonably sized objects can be detected from as far as 130 m away.