Hybrid Communication System Research Articles

Design and Evaluation of a Hybrid 2D-SWZCC OCMDA System with Multicarrier MM-Wave

This paper presents a hybrid communication system combining optical code division multiple access (OCDMA) and multicarrier millimeter-wave (MM-Wave) architecture operating at 35, 55, 75, and 95 GHz connected to a home network center (HNC) and the end user (EU). Hybrid Link reduces congestion on complex RF networks by combining optical fiber backhaul with radio links. The OptiSystem simulation demonstrates successful data transmission and transmission capacity at 40Gbps over various distances. Furthermore, this new 40G-MM wave OCDMA system that takes advantage of a two-dimensional single-weighted zero cross-correlation (2D-SWZCC) system with a multiplexing scheme of polarization wavelength multiplies the same N channels to M OCDMA code of the MM-Wave system that dramatically increased scalability. The comparative analysis shows that the proposed 2D-SWZCC hybrid algorithm outperforms 1D-SWZCC regarding scalability. This study contributes to developing communication algorithms with high data rates and provides promising solutions for method limitations and scalability in hybrid-MM-Wave-OCDMA architectures.

Enhancing longevity: Sustainable channel modeling for wireless-powered implantable BANs

Wireless body area network (WBAN) has revolutionized the healthcare sector by enabling remote monitoring and control of wearable and implantable devices, providing freedom of mobility to patients. However, wireless channel modeling in BAN is a crucial aspect for designing an efficient off-body, on-body and in-body communication. Due to the unique characteristics of the human body, it aims to characterize the signal propagation through skin, tissues, internal organs and biological fluids of a patient’s body. Moreover, it is important to enhance the battery life of the low-powered devices for a sustainable BAN. In this work, we provide a hybrid communication channel model for wireless power transfer in a BAN including both off-body and in-body communication channels. An indoor room scenario is considered in which a movable patient having an implant inside its body is present along with an RF power source (for example, a Wi-Fi access point) situated in a ceiling corner. Implant is assumed to inhibit energy harvesting capability. For practicability, we have considered the effect of path loss, partition walls, floor attenuation factor along with other important body parameters. Specifically, we aim to statistically characterize this hybrid communication system, for which unique closed-form expressions of the probability distribution functions of the received power have been derived, thereby first calculating the instantaneous power at different layers of human body and then obtaining the closed-form expression for average received power. All the derived mathematical expressions have been verified via numerical simulations. Further, for elongating the lifespan of implants, we investigated the average power harvested by an implant and its power outage probability for analyzing the sustainability of implants. The results are numerically validated, considering different types of indoor room scenarios, in addition to providing key design insights.

Research progress of OWC/RF hybrid communication system

Research progress of OWC/RF hybrid communication system

CONCEPTS OF THE DEVELOPMENT OF A CIVIL NETWORK SYSTEM OF UNDERWATER TRAFFIC CONTROL

The article examines the development of underwater space in the interests of maritime freighttransport as such, which increases the carrying capacity of existing sea transport routes, increasesenergy efficiency and reduces the risks of freight transport, provided there is no negative impact on themovement of the vehicle by wind, surface waves and drift currents. It is proposed to create anextensive system of cargo transportation in the underwater space as an alternative to conventionalshipping. The best underwater data exchange in terms of speed and volume of transmitted informationis provided by laser methods. In second place is radio communication in the microwave range and inthird place is the hydroacoustic communication channel. Thus, underwater data transmission based onlasers and radio waves is effective for data transmission only in conditions where the underwatertransport vessel moves in the near-surface layer of the ocean. In the future, hybrid data exchangesystems will be created under water, based on the physical principles of data transmission by radio,laser, hydroacoustic communication. Hybrid communication systems based on hydroacoustics andradar are not excluded. Keywords: Underwater space, underwater vehicles, hydroacoustic, navigation, cargotransportation.

Adaptive overcurrent protection scheme coordination in presence of distributed generation using radial basis neural network

The operational performance of conventional overcurrent protection relay coordination connected to a distribution network is adversely affected by the penetration of distributed generators (DG) at different buses in the network. To address this problem, this paper proposes a novel adaptive protection coordination scheme using a radial basis function neural network (RBFNN), which automatically adjusts the overcurrent relay settings, i.e., time setting multiplier (TSM) and plug setting multiplier (PSM) based on the penetration of DGs. Short circuit currents and voltages measured at different buses are acquired using the remote terminal units (RTU) connected to different buses within the terminal network. Communication between the various remotes and local end station RTUs is through hybrid communication systems of fiber optic and power line communication system modules. The new adaptive overcurrent protection scheme is applied to the IEEE 33-bus distribution network with and without DGs, for single and multi-DG penetration using both the ETAP and MATLAB software. The simulation results show the proposed scheme significantly improves the protection coordination.

Performance Analysis of Multi-Hop Hybrid FSO/mm Wave Communication System for Next-Generation Wireless Networks

Next-generation wireless networks are facing increasing demand for high data rates, low latency, and seamless connectivity. To address these challenges, a multi-hop hybrid communication system integrating Free Space Optics (FSO) and millimeter wave (mm Wave) technologies for backhaul communication is proposed. This system combines the advantages of FSO, such as high bandwidth and low latency, with the robustness and reliability of mm Wave technology. The multi-hop architecture enables the formation of a network of interconnected nodes, providing improved coverage and flexibility. Each node is equipped with FSO and mm Wave transceivers, allowing for seamless handovers and adaptive routing. For the proposed system, analytical formulas for outage probability (OP) and average bit error rate (ABER) are derived and validated using simulations. The Monte Carlo simulations provide evidence of enhanced performance in the proposed Multi-Hop Hybrid FSO/mm Wave (MHFM) system compared to the FSO system.

A comprehensive review of performance analysis of RF-FSO hybrid communication systems

The combination of radio frequency (RF) and free-space optical (FSO) communication has grown in importance as a study area for wireless communication systems in recent years. This technology has the ability to address the rising need for high-speed, high-capacity wireless communication in a variety of applications by successfully integrating the benefits of both RF and FSO communication. The performance analysis of various communication systems based on RF-FSO hybrid technology is covered in detail in this research. An overview of the RF-FSO hybrid technology and its many architectures follows the introduction of the key features and benefits of RF and FSO communication. The performance analysis of several RF-FSO hybrid communication systems, including relay-assisted RF-FSO systems, cooperative diversity RF-FSO systems, and dual-hop RF-FSO systems, are discussed in detail. The performance metrics, such as bit error rate (BER), outage probability, and channel capacity, is analyzed and compared for these systems. Based on the analysis of existing literature, several key conclusions are drawn. First, RF-FSO hybrid technology can provide higher data rates and greater reliability than traditional communication systems. Secondly, the performance of the RF-FSO hybrid system, which combines the advantages of RF technology and FSO technology, has bright development prospects. Finally, the RF-FSO hybrid system can also be combined with other systems for better performance and wider application scenarios.

Performance analysis of a hybrid FSO/mmWave/THz system for short-range communication under rain and fog conditions

For fronthaul cellular networks, the suitability of a hybrid free space optical (FSO)/radio frequency (RF) high data rate communication systems such as millimeter wave (mmWave) and terahertz (THz) with reliable connectivity under weather conditions (rain and fog) is proposed and analyzed. The aim of this hybrid system is to suit short-range communication covering 5G/6G and beyond cellular networks. The 4 pulse amplitude modulation (PAM) scheme parallel transmission and adaptive receiver approach is considered for the work. The theoretical work on estimating the attenuation characteristics under various weather conditions is carried out followed by the simulation of a hybrid communication system for obtaining the received power at different link lengths. Based on the received power for a data rate of 1 Gbps signal-to-noise ratio (SNR) and bit error rate (BER) is calculated for a link length of 0.2 km, 0.5 km, and 1 km for 4 PAM. For varying fog conditions, mmWave/THz carrier is found to be suitable with a BER of 10−10 at a link length of 0.5 km. For varying rain rates, FSO performs well with a BER of 10−8. The link length and performance can be improved with increased transmit power in both communication systems. The THz carrier offers a high data rate, and a hybrid system is proposed with FSO/THz to have reliable connectivity in harsh weather scenarios.

UWB and MB-OFDM for Lunar Rover Navigation and Communication

This paper presents a comprehensive study of ultra-wideband (UWB) and multi-band orthogonal frequency-division multiplexing (MB-OFDM) technologies for lunar rover navigation and communication in challenging terrains. Lunar missions pose unique challenges, such as signal propagation in the lunar environment, terrain elevation, and rover movement constraints. To address these challenges, we propose a hybrid communication and navigation system that leverages UWB technology for high-precision positioning and MB-OFDM for robust and high-throughput communication. We develop a realistic simulation framework that incorporates terrain elevation, obstacles, and rover movement constraints, along with a simple fading model for communication. Simulation results demonstrate the effectiveness of the proposed system in navigating lunar rovers to their target locations while maintaining reliable communication links with a lunar lander. A novel approach based on game theory for rover navigation is also presented. The study provides valuable insights into the design and optimization of communication and navigation systems for future lunar missions, paving the way for seamless integration of advanced terrestrial technologies in extraterrestrial environments.

Analysis of Eavesdropping Region in Hybrid mmWave-Microwave Wireless Systems

Hybrid communication systems, where millimeter-wave (mmWave) links coexist with microwave links, have been an essential component in the fifth-generation (5G) wireless networks. Nevertheless, the open feature of the wireless medium makes hybrid systems vulnerable to eavesdropping attacks. Eavesdroppers in hybrid communication systems can enhance their attack performance by opportunistically eavesdropping on mmWave or microwave links. This paper, therefore, aims to answer a natural question: in which region do eavesdroppers prefer the mmWave links? To this end, we first formulate this question as an eavesdropping region characterization problem from the physical layer security perspective, where eavesdroppers select the link to eavesdrop based on the ratio between the security performances of the mmWave and microwave links. To model the security performances of both the mmWave and microwave links, we derive closed-form expressions for the secrecy outage probabilities and lower bounds/exact expressions for the secrecy rates of both links. Finally, we provide numerical results to validate our theoretical analysis and also illustrate the mmWave eavesdropping region under various network parameter settings.

Achromatic Broadband Multi‐Layer Diffraction Mode Multiplexing

AbstractEfforts have been made in recent years to achieve broadband mode‐division multiplexing (MDM) for wavelength and mode hybrid multiplexing optical interconnect. However, most multiplexers are suffering from either strong chromatic aberration or material dispersion, like planar lightwave circuits, mode selective couplers, and single‐layer diffraction elements. The multi‐layer diffraction structure provides a method for achieving both mode conversion and broadband properties. However, the reported multi‐layer diffraction MDM can usually only achieve high efficiency working at a specific narrow bandwidth due to the monochromatic coherent light design. Here, a general achromatic broadband multi‐layer diffraction model is proposed to compensate the dispersion by wavefront matching of discrete multi‐wavelength optical fields. Using this model, an achromatic orbital angular momentum beam generator and an achromatic linearly polarized mode multiplexer for coarse wavelength‐division multiplexing (CWDM) optical interconnections are designed. Compared with the monochromatic designs, the generator exhibits lower wavelength dependence and the multiplexer doubles the bandwidth with mode purity exceeding 91%. Additionally, signal transmission over a 5‐km fiber is demonstrated experimentally in the CWDM‐MDM hybrid communication system. This work represents a solid step toward practical implementation of achromatic MDM and may find applications in the design of various achromatic devices.

Analysis of LDPC Code in Hybrid Communication Systems

Free-space optical (FSO) communication is of supreme importance for designing next-generation networks. Over the past decades, the radio frequency (RF) spectrum has been the main topic of interest for wireless technology. The RF spectrum is becoming denser and more employed, making its availability tough for additional channels. Optical communication, exploited for messages or indications in historical times, is now becoming famous and useful in combination with error-correcting codes (ECC) to mitigate the effects of fading caused by atmospheric turbulence. A free-space communication system (FSCS) in which the hybrid technology is based on FSO and RF. FSCS is a capable solution to overcome the downsides of current schemes and enhance the overall link reliability and availability. The proposed FSCS with regular low-density parity-check (LDPC) for coding techniques is deliberated and evaluated in terms of signal-to-noise ratio (SNR) in this paper. The extrinsic information transfer (EXIT) methodology is an incredible technique employed to investigate the sum-product decoding algorithm of LDPC codes and optimize the EXIT chart by applying curve fitting. In this research work, we also analyze the behavior of the EXIT chart of regular/irregular LDPC for the FSCS. We also investigate the error performance of LDPC code for the proposed FSCS.

LambdaRoad: planning for future hybrid communication along the road network

The road transport system is facing one of its major transformations since the introduction of the internal combustion engine. The emergence of new technologies that facilitate the development towards increased digitalization and automation of vehicles is causing a paradigm shift in the transport sector, requiring a fundamental upgrade of the current communication infrastructure. Within the Norwegian research project LambdaRoad, the planning of a hybrid communication system is investigated utilizing both mobile network and ITS-G5 communication. Within this project a map-based planning tool is developed to investigate the coverage of communication (in terms of signal strength) along the road network.

Highly sensitive broadband terahertz modulator based on MAPbI<sub>3</sub>/Graphene/Si composite structure

A high-performance silicon-based terahertz modulator is one of the key devices for building an ultrawideband terahertz-fiber hybrid communication system. In this paper, an ultrawideband terahertz modulator with large modulation depth based on a chalcogenide/graphene/silicon (MAPbI<sub>3</sub>/Graphene/Si) composite structure driven by near-infrared light (NIR) is proposed. The experimental results show that the graphene thin film and the chalcogenide hole transport layer can effectively promote the interfacial charge separation, increase the carrier complex lifetime, significantly enhance the surface conductivity of the device, further modulate the terahertz wave transmission amplitude, and realize the function of the light-controlled terahertz wave modulator under the NIR light drive. The terahertz transmission characteristics of the device are characterized by an 808 nm NIR modulation excitation source, and a large modulation depth of up to 88.3% is achieved in an ultra-wide frequency range of 0.2–2.5 THz and a low power density of 6.1 mW/mm<sup>2</sup> driven by NIR light, which is much higher than that of the bare silicon substrate (14.0%), with the significant advantages of high sensitivity, broadband, and large modulation depth. The corresponding semi-analytical device model is established and the experimental results are verified by simulation. The proposed MAPbI<sub>3</sub>/Graphene composite thin film is effective in enhancing the silicon-based modulator performance and provides a new strategy for the future integration of silicon-based terahertz modulators in NIR terahertz-fiber hybrid communication systems.

‘What tools should we use?’: Politicized youth’s perspectives on digital activism in the Basque Country

As has occurred with all political activism, contentious counter-hegemonic activism has found a new space for political action on the internet. The massive expansion of digital space in recent years has increased the socializing importance of the field of communications, especially among young people. However, it is not known to what extent the use of internet-based tools has spread in the contemporary protest repertoires of young Basque activists. Based on qualitative research carried out with young pro-independence nationalist activists in the Basque Country in the period following the end of ETA’s armed activity, the main objective of this article is to analyse the scope and limits of digital activism from the point of view of these new political subjects. The principal finding is that activists construct hybrid communication systems, in which physical and virtual spaces are combined, and where their inheritance of a community-based counter-hegemonic political activism and experimentation with new forms have come together.

Performance of NOMA-Based Dual-Hop Hybrid Powerline-Wireless Communication Systems

The mixture of wireless and power line communications (PLC) is vital for implementing new applications in smart grid and vehicular communications. In this work, we investigate the performance of non-orthogonal multiple access (NOMA) based dual-hop hybrid communication systems with decode-and-forward relay. The wireless channel is characterized by Nakagami- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> fading under an additive white Gaussian noise (AWGN), while the PLC channels are characterized by Log-normal distribution with Bernoulli Gaussian noise including both background and impulsive noise components. New closed-form expressions for the outage probability, the asymptotic outage probability and ergodic capacity are derived and verified via extensive representative simulations. For more insights on the outage performance, we analyze the diversity order. Additionally, we proposed a power allocation optimization technique to achieve an outage-optimal performance. The results show that the system outage probability improves as the impulsive noise index and the arrival probability of the impulsive component of the PLC additive noise decrease, while their effect is negligible on the ergodic capacity. Finally, the performance of the proposed system is compared against a benchmark OMA-based system.

A metasurface-based light-to-microwave transmitter for hybrid wireless communications.

Signal conversion plays an important role in many applications such as communication, sensing, and imaging. Realizing signal conversion between optical and microwave frequencies is a crucial step to construct hybrid communication systems that combine both optical and microwave wireless technologies to achieve better features, which are highly desirable in the future wireless communications. However, such a signal conversion process typically requires a complicated relay to perform multiple operations, which will consume additional hardware/time/energy resources. Here, we report a light-to-microwave transmitter based on the time-varying and programmable metasurface integrated with a high-speed photoelectric detection circuit into a hybrid. Such a transmitter can convert a light intensity signal to two microwave binary frequency shift keying signals by using the dispersion characteristics of the metasurface to implement the frequency division multiplexing. To illustrate the metasurface-based transmitter, a hybrid wireless communication system that allows dual-channel data transmissions in a light-to-microwave link is demonstrated, and the experimental results show that two different videos can be transmitted and received simultaneously and independently. Our metasurface-enabled signal conversion solution may enrich the functionalities of metasurfaces, and could also stimulate new information-oriented applications.

A survey and bibliometric analysis of different communication technologies available for smart meters

A smart energy meter is one of the most significant smart grid products. The smart energy meter (SEM) is an advanced energy meter that collects data from end users' load devices, monitors energy usage, and then sends the data to the smart grid. Advanced Metering Infrastructure (AMI) is used by smart energy meters to send real-time consumption data to utilities and customers. It is made possible by the Internet of Things (IoT), which expands the internet's capabilities to enable machine-to-machine or machine-to-server communication. Smart meters can communicate with each other using a variety of communication technologies. This paper presents a survey on communication technologies to determine the suitable technology based on a few parameters like cost-effectiveness, security, long-range, low power consumption, and data rate that are pre-requisite for smart meter communication. Firstly, a short literature survey is conducted to investigate the previous researches and challenges associated with communication technologies. The findings and future work of these articles are then summarized in a separate table for a clear understanding for the readers. Following that, an overview of communication technologies and their pros and cons are presented to understand critical aspects of each technology. A bibliometric analysis is also done to find the top countries, universities, and authors with greater incidence in this subject area worldwide by extracting citation data from Scopus and Web of Science. Besides, a comparison of major communication technologies is made in the discussion. Additionally, based on the parameters and literature reviewed, this paper suggests some suitable communication technologies for smart meters. It presents a model of a cost-effective hybrid communication system for smart metering and AMI. Finally, the possible issues and challenges related to communication technologies are discussed. Based on the challenges, several future research directions are also provided, which may lead to promising findings in the near future.

Hybrid Power Line/Wireless Systems: Power Allocation for Minimizing the Average Bit Error Probability

This paper investigates power allocation for minimizing the average bit error probability (BEP) in hybrid communication systems, more specifically hybrid power line/wireless systems (HPWSs). In this regard, a brief discussion of HPWSs is presented in order to point out the complementary characteristics of power line and wireless media. By considering orthogonal frequency-division multiplexing and maximal-ratio combining, optimization problems associated with the minimization of the average BEP in hybrid communication systems are formulated under two distinct transmission power constraints, called sum power and sum power-channel constraints. For both constraints, it is demonstrated that at most one medium should be used for data transmission over subchannels with the same index in order to minimize the average BEP in hybrid communication systems. Based on this finding, power allocation algorithms are derived for this purpose in HPWSs. Numerical analyses are then used to validate the proposed algorithms by comparing them with interior-point-based power allocation algorithms. In addition, performance comparisons show the advantage of the proposals over alternative algorithms from the literature, including previous algorithms proposed for maximizing the achievable data rate.

HYBRID COMMUNICATION NETWORK FOR THE PURPOSE OF MARITIME APPLICA TIONS

The article presents the concept of the hybrid communication system for the purpose of maritime applications. The main idea of this system is that it will utilize the seamless roaming concept, which means the communication link at sea will be established automatically (and seamlessly for the user), using many possible communication techniques (cellular, LTE, Wi-Fi, VDES, etc.) which will be selected depending on the current conditions of the radio channel and the requirements and preferences of the user. The paper will introduce the general architecture of the system, the concept of the maritime cloud and the seamless roaming, including the way the latter will be implemented in the system. The authors will also briefly introduce the proposed test-bed of the system’s on-board device. The system presented in the article is one of the major topics of the EfficienSea 2 project (co-funded from the ‘Horizon 2020’ programme) in which the authors of the paper participate.