Data Communication Link Research Articles

Continuous Power Management of Decentralized DC Microgrid Based on Transitional Operation Modes under System Uncertainty and Sensor Failure

Continuous power management for a decentralized DC microgrid (DCMG) is proposed in this study to achieve power balance and voltage regulation even under system uncertainty and voltage sensor failure. The DCMG system achieves continuous power management through only the primary controller to reduce the computational burden of each power agent. To enhance the reliability and resilience of the DCMG system under DC bus voltage (DCV) sensor failure, a DCV sensor fault detection algorithm is suggested. In this algorithm, DCV sensor failure is detected by comparing the measured DCV with the estimated DCV. If power agents identify the failure of the DCV sensor, it changes the operation properly according to the proposed control mode decision algorithm to guarantee the stability of the DCMG system. When uncertain conditions like sudden grid disconnection, DCV sensor failure, electricity price change, power variation in distributed generations, and critical battery status occur, the DCMG system is changed to transitional operation modes. These transitional operation modes are employed to transmit the power agent information to other agents without digital communication links (DCLs) and to accomplish power sharing even under such uncertain conditions. In the transitional operation modes of the DCMG system, the DCV levels are temporarily shifted to an appropriate level, enabling each power agent to detect the uncertainty conditions, and subsequently to determine its operation modes based on the DCV levels. The reliability and effectiveness of the proposed control strategy are confirmed via various simulation and experimental tests under different operating conditions.

Multilayer Graphene/Epitaxial Silicon Near‐Infrared Self‐Quenched Avalanche Photodetectors

Abstract2D materials and their heterostructures exhibit considerable potential in the development of avalanche photodetectors (APDs) with high gain, response, and signal‐to‐noise ratio. These materials hold promise in addressing inherent technical challenges associated with APDs, such as low light absorption coefficient, elevated noise current, and substantial power consumption due to high bias resulting in only moderate current gain. In this work, a macro‐assembled graphene nanofilm (nMAG)/epitaxial silicon (epi‐Si) vertical heterostructure photodetector with a responsivity of 0.38 A W−1 and a response time of 1.4 µs is reported. The photodetectors use high‐quality nMAG as the absorption layer and a lightly‐doped epi‐Si layer as the multiplication region under the avalanche mode to provide a high responsivity (2.51 mA W−1) and detectivity (2.67 × 109 Jones) at 1550 nm, which can achieve high‐resolution imaging. In addition, the APD displays a weak noise level and an avalanche gain of M = 1123. It can work with relatively low avalanche turn‐on voltages and achieve self‐quenching by switching from illumination to dark during avalanche multiplication, with a real‐time data transfer rate of 38 Mbps in near‐infrared light communication data links. The proposed structure enables the fabrication of high‐performance APDs in the infrared range using complementary‐metal‐oxide‐semiconductor (CMOS)‐compatible processes.

Predictive Modeling of Environmental Impact on Drone Datalink Communication System

In this study, we introduce an innovative model for evaluating the impact of environmental factors on drone-to-ground control station datalink communications. Our approach integrates both deterministic and stochastic processes to account for small-scale and large-scale fading effects, encompassing propagation attenuation, the Rician fading model, and Gaussian noise to accurately reflect real-world conditions. The model is implemented on signals transmitted using spread spectrum modulation. Through a comparative analysis of the model’s predictions against actual signals received in three distinct environments, the model’s efficacy in diverse scenarios is affirmed. Error metrics obtained from Monte Carlo simulations are employed to validate the theoretical results against experimental data. The proposed approach is pivotal for predicting the transmission range and understanding the electromagnetic susceptibility of the datalink, offering a substantial contribution to the optimization of remote drone control.

Development of Communication System for UAV Ground Control Station with ATC Based on Controller Pilot Data Link Communication

The technology of Unmanned Aerial Vehicles (UAVs), or drones, has rapidly evolved over the years, taking on various missions such as delivery, agriculture, mapping, surveillance, firefighting, and more. With the expanding functions of drones, the operational areas of UAVs also increase. However, there are restricted locations for UAV operations, one of which is an airport. Operating UAVs in controlled airspace requires permission from the government and local regulators. Moreover, a reliable communication system is crucial to support operations and prevent failures. This paper discussed the development of a communication system between UAV Ground Control pilots and Air Traffic Control (ATC) operators. The system utilizes strategic and tactical messages, developing the UAV communication system architecture based on the Controller Pilot Data Link Communication (CPDLC) standard operating procedures. This involved the design of the UAV Ground Control Station (GCS) communication system and the analysis of transmission power. The CPDLC system is a text-based communication system using the internet to send messages to ATC at an airport. The research methods included literature studies, collecting CPDLC messages based on documents (GOLD), developing the UAV communication system architecture, creating strategic communication standard operating procedures, designing the communication system interface on the GCS, and performing power calculations using link budget analysis. The research results indicate that the transmission power, calculated using the link budget at a distance of 100 km, is 17 dBm for payload communication and 15 dBm for telemetry communication, both meeting the minimum link margin standard of 15 dBm.

In-cabin and outdoor environmental monitoring in vehicular scenarios with distributed computing

Accurate environmental monitoring is becoming the basis for assuring sustainable development in administrations at different levels, including cities and industry as key actors. However, current techniques rely on static stations that may not be representative of larger areas, for the case of outdoor scenarios, or even not considering indoor spaces where people can remain for long periods. This is the case of vehicles. The COVID-19 pandemic has remarked the importance of measuring air quality indoors, for instance. With the aim of solving this two-fold issue, this work proposes an in-cabin and outdoor air pollution monitoring system to assure healthy conditions when travelling, driving and operating vehicles, and to analyse the evolution of environmental parameters in cities. This effort is carried out exploiting distributed computing with micro-services, betting for an on-board hardware solution provided with sensors for measuring particulate matter, CO, CO2, NO2, O3, temperature and humidity. While basic data pre-processing is carried out in this acquisition unit, edge processing is performed on a single board computer aboard and intermediary communication nodes in the network path from the vehicle to the cloud. Vehicle connectivity is provided by 4G cellular and Low-Power Wide-Area (LPWAN) networks. Global environmental perception is acquired by cloud-based software powered by machine learning and time series analysis. The whole solution has been validated and tested in the city of Cartagena (Spain), with good performance in terms of data collection, communication links and service offered.

Research on Transmission Control of Airborne Communication Data Link System Based on Artificial Fish Swarm Algorithm

Research on Transmission Control of Airborne Communication Data Link System Based on Artificial Fish Swarm Algorithm

Decentralized Power Flow Control Strategy Using Transition Operations of DC-Bus Voltage for Detection of Uncertain DC Microgrid Operations

To enhance the reliability and flexibility of DC microgrids (DCMGs), this paper presents a decentralized power flow control strategy (PFCS) by using the transition operation modes. The transition operation modes are introduced as an effective communication method among power units, eliminating the use of additional digital communication links (DCLs) for the purpose of ensuring the power balance as well as the voltage regulation even under uncertain conditions. During the transition operation modes, the power unit which transmits the information shifts the DC-link voltage level, and the power unit which receives the information continuously monitors the DC-link voltage with predetermined time. When uncertain conditions occur in a particular power unit, this power unit triggers the transition operation modes to send this information to all power units in the DCMG system. The proposed PFCS can maintain the DC-link voltage at the nominal value for steady-state conditions both in the grid-connected mode and islanded mode. Moreover, the proposed PFCS significantly enhances the overall reliability of the decentralized DCMG system by effectively addressing several uncertainties stemmed from electricity price fluctuations, grid availability, battery state-of-charge (SOC) levels, and wind power variations. The scalability of the DCMG system is also demonstrated by incorporating an electric vehicle (EV) unit as an additional energy storage system (ESS). The EV unit seamlessly cooperates with the existing battery unit, functioning as additional ESS to regulate the DC-link voltage when the battery SOC level is low. Simulation and experimentation results under various conditions demonstrate the effectiveness of the proposed PFCS.

AKAASH: A realizable authentication, key agreement, and secure handover approach for controller-pilot data link communications

Controller-Pilot Data Link Communications (CPDLC) are rapidly replacing voice-based Air Traffic Control (ATC) communications worldwide. Being digital, CPDLC is highly resilient and bandwidth efficient, which makes it the best choice for traffic-congested airports. Although CPDLC initially seems to be a perfect solution for modern-day ATC operations, it suffers from serious security issues. For instance, eavesdropping, spoofing, man-in-the-middle, message replay, impersonation attacks, etc. Cyber attacks on the aviation communication network could be hazardous, leading to fatal aircraft incidents and causing damage to individuals, service providers, and the aviation industry. Therefore, we propose a new security model called AKAASH, enabling several paramount security services, such as efficient and robust mutual authentication, key establishment, and a secure handover approach for the CPDLC-enabled aviation communication network. We implement the approach on hardware to examine the practicality of the proposed approach and verify its computational and communication efficiency and efficacy. We investigate the robustness of AKAASH through formal (proverif) and informal security analysis. The analysis reveals that the AKAASH adheres to the CPDLC standards and can easily integrate into the CPDLC framework.

INVESTIGATION OF THE APPLICATION OF CPDLC TO AERODROME AIR TRAFFIC CONTROL PROCEDURES

This paper analyzes the application of Controller Pilot Data Link Communication (CPDLC) technology to different air traffic control sectors. It also presents the analysis of the performed research and tests. A CPDLC program is being developed that is adapted for aerodrome flight control. The program takes into account the advantages and disadvantages of other software, as well as the recommendations of other authors. The program is developed using JAVASCRIPT and HTML programming languages. The tests of the developed CPDLC program are performed in the Expert NITA flight control simulator. The CAPAN method is used for data analysis. Analysis of changes in workload, language errors, and time saved using different communication methods during simulations is also performed.

Circularly polarized differential intra-oral antenna design validation and characterization for tongue drive system

Assistive devices are becoming increasingly popular for physically disabled persons suffering tetraplegia and spinal cord injuries. Intraoral tongue drive system (iTDS) is one of the most feasible and non-invasive assistive technology (AT), which utilises the transferring and inferring of user intentions through different tongue gestures. Wireless transferring is of prime importance and requires a suitable design of the intra-oral antenna. In this paper, a compact circularly polarized differential intra-oral antenna is designed, and its performance is analysed within heterogeneous multilayer mouth and head models. It works at 2.4 GHz in the Industrial, Scientific, and Medical (ISM) band. The footprint of the differential antenna prototype is 0.271 λgtimes 0.271 λgtimes 0.015 λg. It is achieved using two pairs of spiral segments loaded in diagonal form near the edges of the central rotated square slot and a high dielectric constant substrate. Its spiral-slotted geometry further provides the desired swirling and miniaturization at the desired frequency band for both mouth scenarios. Additionally, corner triangular slits on the radiating patch assist in tuning the axial ratio (< 3 dB) in the desired ISM band. To validate the performance of the proposed in-mouth antenna, the measurement was carried out using the minced pork and the saline solution for closed and opened mouth cases, respectively. The measured − 10 dB impedance bandwidth and peak gain values in the minced pork are from 2.28 to 2.53 GHz (10.39%) and − 18.17 dBi, respectively, and in the saline solution, are from 2.3 to 2.54 GHz (9.92%) and − 15.47 dBi, respectively. Further, the specific absorption rate (SAR) is estimated, and the data communication link is computed with and without a balun loss. This confirms that the proposed differential intraoral antenna can establish direct interfacing at the RF front end of the intraoral tongue drive system.

Cost- and Delay-Efficient Backhaul Selection for Time-Sensitive Maritime Communications

Extending the existing near-shore terrestrial infrastructure with non-terrestrial network capabilities helps maritime operators alleviate the high costs of communication and meet the requirements imposed by time-sensitive applications. Recognizing that the deployment of terrestrial and non-terrestrial networks necessitates selecting from the available wireless backhaul solutions, which have dissimilar data transmission costs and communication link qualities, it is essential to propose an appropriate backhaul selection policy. Specifically, in this letter, we coin a backhaul selection policy that manages the inherent trade-off between data transmission expenses and timely throughput guarantees for maritime communications. We formulate the backhaul selection problem as a Markov decision process and show that the proposed solution is not only more cost-efficient, but also satisfies the timely throughput requirements in contrast to currently used greedy strategies.

The Fifth Bioelectronic Medicine Summit Hosted by the Feinstein Institutes for Medical Research (Manhasset, NY) and Columbia Engineering (NY, NY) at The Garden City Hotel, Garden City, NY 11530 on October 11-12th, 2022- Bioelectronic Medicine: Today’s Tools, Tomorrow’s Therapies

The Fifth Bioelectronic Medicine Summit Hosted by the Feinstein Institutes for Medical Research (Manhasset, NY) and Columbia Engineering (NY, NY) at The Garden City Hotel, Garden City, NY 11530 on October 11-12th, 2022- Bioelectronic Medicine: Today’s Tools, Tomorrow’s Therapies

Retracted: To Improve the Real‐Time Performance of Airborne Data Link Communication System

Retracted: To Improve the Real‐Time Performance of Airborne Data Link Communication System

Investigation of optimum FSO communication link using different modulation techniques under fog conditions

The FSO communication system offers high data rate investigated over the last few decades because of extraordinary advantages like unlicensed frequency and bandwidth at low power consumption, simple design, hasty, and minimal installation cost, including no right of way. It is essential to investigate solutions against degrading factors like absorption and scattering caused by fog, dust, rain, smog, and uncertain temperature variation of environmental channels. In this work various modulation techniques (AM, CS-NRZ, CS-RZ, DB-NRZ, MDB-NRZ, MDB-RZ, RZ, NRZ) are simulated and used to mitigate the weather attenuation of the specific airfield of Lahore, Pakistan under fog conditions, to provide a reliable FSO communication link for high data rate up to 40 Gbps over a link distance from 1.2 to 1.8 km at transmitted power up to 34 dBm in congested region. The real-time visibility data was taken metrological department for the estimation of attenuation under fog conditions and simulated using Optisys software for further investigation. To choose an FSO communication link, analysis for data rate, link distance, SNR, BER and Q-factor are performed under fog conditions using eight different modulation techniques. An increase in signal channel loss has been observed under fog conditions and performance of the FSO communication system is degraded consequently. The 3 R’s (range, rate, and reliability) depend on each other if the link range is tarnished in a foggy condition that will also degrade the data rate and subsequently, reliability of the FSO system. It is observed that for maximum link distance, the performance parameters of AM modulation technique are prominent and more efficient, offering better Q-factor value at 6.08 dB, lower bit error rate at 7.03 × 10−10, and better SNR of 4.29 dB. The results also show that AM modulation technique offers better signal-to-noise power and has good SNR due to well-received signal power as compared to all other modulation techniques. This research will be helpful to design and implement an FSO communication system under foggy conditions in a metropolitan city to provide a high data communication link among different national institutions.

Seamless Power Management for a Distributed DC Microgrid with Minimum Communication Links under Transmission Time Delays

To maintain voltage stabilization under transmission time delays, this paper proposes a seamless power management scheme for a distributed DC microgrid (DCMG) with minimum digital communication links (DCLs). First, a DCL topology with minimum communication data is presented for the construction of distributed DCMG system not only to mitigate the communication burden but also to enhance the system’s flexibility and reliability. In addition, based on information gathered from nearby agents and local measurements, the operating modes of local agents in a DCMG system are determined properly to ensure a proper power balance under various conditions. During normal operation, the proposed scheme works as a distributed control scheme either in the grid-connected or islanded mode to take advantage of the distributed control method. To maintain seamless power management even under transmission time delays such as grid fault detection delays and grid recovery detection delays, the operating modes of each agent in a DCMG system are switched to a decentralized scheme based on the droop control method. When the utility grid information is properly identified by all power agents after a transmission time delay, the DCMG system returns to the distributed control scheme based on DC-link voltage (DCV) control to guarantee voltage stabilization. Furthermore, the scalability issue of a distributed DCMG system is also considered in this paper when an additional energy storage system (AESS) agent is involved in the DCMG system. For this purpose, a DCL topology with minimum communication data is designed for the AESS, which enables power units to participate in or to leave the distributed DCMG system easily. Simulation and experimental results under various conditions demonstrate the effectiveness and reliability of the proposed seamless power management strategy.

Numerical Investigation of Optical and Photoelectric Properties for 850 nm VCSELs with Arbitrary Crystal Orientation

High-speed VCSELs are widely used for high-capacity, short-range data communication links. Here, we numerically investigate the optical and electronic properties of a crystal orientation-dependent 1.06% compression InGaAs-AlGaAs laser emitting around 850 nm. The reduction of the density of states is observed in the largest energy range for the quantum well in the (110) orientation compared with the conventional (001) orientation. The calculated transparency carrier density decreases from 2.74 × 1018 cm−3 to 1.88 × 1018 cm−3 with the gain coefficient rising from 4969.4 cm−1 to 5427.2 cm−1 in (110) orientation. The 3 dB bandwidth of 31.25 GHz is realized in the (110) orientation, which can support 60 Gbps (NRZ) applications.

A Study of BER and EVM Degradation in Digital Modulation Schemes Due to PLL Jitter and Communication-Link Noise

A phase-locked-based frequency synthesizer – ubiquitously used to generate local oscillation in a communication transceiver – exhibits phase noise and jitter which considerably degrades bit-error rate (BER) and error vector magnitude (EVM) of a digital communication link. This paper presents an analytical study of EVM and BER degradation for a variety of widely used digital modulation schemes. Phase noise and jitter of a generic integer-N phase-locked loop (PLL) as a local oscillator feeding an RF mixer are derived, while accounting for the reference spurs and cyclo-stationarity of the mixer operation as well as the additive noise of the communication link. This jitter model is then utilized to directly study its impact on digital modulation constellations. Specifically, the EVM and BER degradation due to the PLL jitter in communication systems incorporating M-ary phase-shift keying (M-PSK) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${4^{M}}$ </tex-math></inline-formula> quadrature amplitude modulation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${4^{M}}$ </tex-math></inline-formula> QAM) are analyzed. Comparison between analytical models and system-level simulations verifies an excellent accuracy of these models.

Polymer modulators in silicon photonics: review and projections.

Optical modulators are vital for many applications, including telecommunication, data communication, optical computing, and microwave photonic links. A compact modulator with low voltage drive requirement, low power, high speed, and compatibility with CMOS foundry process is highly desirable. Current modulator technologies in Si suffer from trade-offs that constrain their power, performance (speed, drive voltage), and area. The introduction of additional materials to the silicon platform for efficient phase shift promises alternatives to relax those trade-offs. Si-organic-hybrid (SOH) devices demonstrate large modulation bandwidth leveraging the electro-optic (EO) effect and smaller drive voltage or footprint owing to a strong EO coefficient. In this study, we review various SOH modulators and describe their path towards integration to silicon, including their challenges associated with aging and temperature. We also briefly discuss other high-performance modulators such as plasmonic-organic-hybrid (POH), photonic-crystal-assisted SOH, and LiNbO3.

Cislunar distributed architectures for communication and navigation services of lunar assets

The last decade saw a renewed interest on the Moon as a well suited training premise in preparation to manned mission to Mars, but also as an interesting target itself, for scientific investigations, technological developments and new markets opportunities. As a result, numerous and very different missions to the Moon are currently being studied and implemented, assuming to have our satellite quite crowded soon.Such a scenario motivates the settling of space infrastructures to offer recurrent services like data relays, communication links and navigation in the cislunar environment which would facilitate and enlighten the single mission’s implementation and operation.The paper presents the strategy adopted to address the design of the orbital configuration for a distributed architecture to answer the communication and navigation needs to serve at the best the diversified lunar missions scenario expected for the next decades. First, a set of parameters of merit are identified and explained in their mathematical expression and physical meaning. Then, different regions of interest for possible future missions are identified and mapped to the relevant performances wanted for that specific region. Last a Multi-Objective Optimisation framework is presented, both in the exploited genotype and the different objectives participating to the definition of the cost function, in order to provide a versatile tool.The paper critically discusses the effectiveness of the proposed approach in detecting the best suited distributed orbital architectures for the servicers according to the expected service performance in specific user regions, spread all over the Earth–Moon volume — from Earth vicinity to Lunar surface, considering also robustness aspects. The benefits in the exploitation of the multibody dynamical regime offered by the Earth–Moon system to set up the most promising orbital set with a minimum number of servicing spacecraft are underlined as well.

Remote Run-Time Failure Detection and Recovery Control For Quadcopters

We propose an adaptive run-time failure recovery control system for quadcopter drones, based on remote real-time processing of measurement data streams. Particularly, the measured RPM values of the quadcopter motors are transmitted to a remote machine which hosts failure detection algorithms and performs recovery procedure. The proposed control system consists of three distinct parts: (1) A set of computationally simple PID controllers locally onboard the drone, (2) a set of computationally more demanding remotely hosted algorithms for real-time drone state detection, and (3) a digital twin co-execution software platform — the ModelConductor-eXtended — for two-way signal data exchange between the former two. The local on-board control system is responsible for maneuvering the drone in all conditions: path tracking under normal operation and safe landing in a failure state. The remote control system, on the other hand, is responsible for detecting the state of the drone and communicating the corresponding control commands and controller parameters to the drone in real time. The proposed control system concept is demonstrated via simulations in which a drone is represented by the widely studied Quad-Sim six degrees-of-freedom Simulink model. Results show that the trained failure detection binary classifier achieves a high level of performance with F1-score of 96.03%. Additionally, time analysis shows that the proposed remote control system, with average execution time of 0.49 milliseconds and total latency of 6.92 milliseconds in two-way data communication link, meets the real-time constraints of the problem. The potential practical applications for the presented approach are in drone operation in complex environments such as factories (indoor) or forests (outdoor).