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For the potential of providing rates of multiple Giga-bps in a single channel, millimeter wave (mmWave) communications have recently attracted substantial research interest. While mmWave technology is already being used in stationary scenarios such as indoor hotspots or backhaul, it is challenging to use mmWave frequencies in mobile networks, where transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult. To fully exploit the high potential rates of mmWave in mobile networks, many significant technical challenges must be tackled. The main objective of this IEEE JSAC Special Issue on “Millimeter wave communications for future mobile networks” is to collect the most recent technical advances in mmWave for future mobile networks. The response from the community to the call has been overwhelming. We received 96 submissions with a call period short than 4 months. Many of the submissions are from the most well known research groups in the field. After a strict review process, we decided to accept 38 papers, which will be published in two issues. The papers were selected based on the technical relevance and merits. Unfortunately, due to space limitations, a number of interesting papers were not selected, despite the merits that they had. We sincerely hope those papers can find other publishing venues. [ABSTRACT FROM AUTHOR]

The development of IoT (the Internet of Things) wireless transmission opens a new era in communication systems. In the next years, the development and implementation of IoT systems will be very dynamic. It can be seen that the solutions of LTE – NB-IoT (Long Term Evolution – Narrowband IoT) transmission devices are implemented in a wide range of terrestrial solutions, e.g. smart grids. This paper aims to analyse the possibility of the use of NB-IoT technology for maritime communication applications and partially, for some maritime safety solutions, based on signal coverage analysis at sea. An interesting approach is the comparison of the results of NB-IoT coverage to the classic cellular LTE-based communication systems. Proposed solutions are based on the practical implementation of a designed specialised data concentrator with implemented gateway and radio modems, for both NB-IoT technology as well as LTE. In the paper, analyses of radio link budget and propagation loss models for sea environment are presented. The coverage analysis is based on real measurements of the efficiency of transmissions using wireless modems implemented in the developed data concentrator. [ABSTRACT FROM AUTHOR]

This paper considers a device-to-device (D2D) fog-radio access network wherein a set of users are required to store/receive a set of files. The D2D devices are connected to a subset of the cloud data centers and thus possess a subset of the data. This paper is interested in reducing the total time of communication, i.e., the completion time, required to disseminate all files among all devices using instantly decodable network coding (IDNC). Unlike previous studies that assume a fully connected communication network, this paper tackles the more realistic scenario of a partially connected network in which devices are not all in the transmission range of one another. The joint optimization of selecting the transmitting device(s) and the file combination(s) is first formulated, and its intractability is exhibited. The completion time is approximated using the celebrated decoding delay approach by deriving the relationship between the quantities in a partially connected network. The paper introduces the cooperation graph and demonstrates that the problem is equivalent to a maximum weight clique problem over the newly designed graph. Extensive simulations reveal that the proposed solution provides noticeable performance enhancement and outperforms previously proposed IDNC-based schemes. [ABSTRACT FROM PUBLISHER]

Summary: Intelligent fire safety systems place higher demands on the speed and reliability of data communication between sensors, controllers, and other devices. The two‐wire bus has become a significant trend in developing fire safety communication systems because of its low cost and simple maintenance. This paper proposes a two‐wire bus communication system for fire safety based on orthogonal frequency division multiplexing (OFDM) technology. First, we introduce the low‐voltage power line channel model and conduct relevant simulations, providing the conditions for subsequent simulation work. Then, we design the system's transmission and reception schemes, provide the parameters, and introduce each technology used. Finally, we conducted system simulations based on three different channel models, and the system performance is compared among different encoding, modulation, and channel estimation methods. The simulation results show that the system designed in this paper has superior performance compared with other systems and can meet the requirements of intelligent fire safety systems for communication speed and reliability. [ABSTRACT FROM AUTHOR]

The micro and small unmanned aerial vehicles (msUAVs) internet of things has been widely used in different fields. At the same time, the disordered flight of msUAVs inevitably become a potential threat to public security (such as airports, railway stations, major event venues, etc.). In view of the safety problem of msUAVs, the anti-micro and small unmanned aerial vehicles (AmsUAVs) is used to solve the defense problem of msUAVs in public safety places. The system blocks the communication link of the msUAVs by transmitting high power to achieve the purpose of low altitude control. At the same time, the AmsUAVs will also cause interference to the uplink of other nearby radio communication systems, such as civil aviation and mobile communication systems, In this paper, an analysis method based on the interference-to-noise ratio (INR) criterion is proposed and interference analysis is performed on AmsUAVs and some mobile communication systems uplink. First, to control msUAVs, it is necessary to calculate the minimum transmit power of the AmsUAVs in the corresponding frequency band according to the uplink and the radio wave propagation distance of the msUAVs. Second, to avoid harmful interference to other radio commnication systems (e.g., CDMA and TD-LTE), the frequency and distance separation between the AmsUAVs and mobile communication systems should be calculated according to factors such as application scenarios, radio wave propagation distance, and working frequency band. Finally, a simulation analysis provides the transmit power, off-axis angle, frequency separation, and distance separation of the AmsUAVs and mobile communication base station in different environments. [ABSTRACT FROM AUTHOR]

The frequency of natural disasters has increased recently, posing a huge threat to human society. Rapid, accurate, authentic, and comprehensive acquisition and transmission of disaster information are crucial in emergency response. In this paper, we propose a design scheme for an aerial remote sensing platform based on real-time satellite communication. This platform mainly includes a civilian heavy-duty unmanned aerial vehicle, ground observation system with the self-developed orthographic image stabilization device, wireless communication system with an airborne mobile communication device using Ku band, ground satellite information receiving station, and data processing and application analysis system. The image stabilization capability of the ground observation system and the communication capability of the wireless communication system were verified through ground and flight tests respectively. The results showed that the stability accuracy of the platform was better than the theoretical threshold, the system transmission rate was not less than 2 M bandwidth, the data packet loss rate was low, and the time delay was not more than 2 s. The images captured in the experiment were clear, with a resolution of less than 1cm and an overlap rate of more than 70%. These all results meet the emergency observation requirement, which indicates that the aerial remote sensing platform based on real-time satellite communication has great potential for application in natural disaster emergency response. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach towards space–ground integrated communication systems by combining terrestrial cellular networks, UAV networks, and satellite networks, leveraging advanced slicing technology. The proposed architecture addresses the challenges posed by future user surges and aims to reduce network overhead effectively. Central to our approach is the introduction of a marginal mobile station (MS)-assisted network resource allocation decision architecture. Building upon this foundation, we introduce the DP-DQN model, an enhanced decision-making algorithm tailored for MSs in dynamic network environments. Furthermore, this study introduces a feedback mechanism to ensure the accuracy and adaptability of the marginalization model over time. Through extensive simulations and experimental validations, our DP-DQN-based edge decision method demonstrates substantial potential in alleviating core network overhead while improving success access ratios compared to conventional methods. [ABSTRACT FROM AUTHOR]

The fifth generation (5G) cellular network roll-out provides high-speed performance, better coverage, and ubiquitous connectivity for the next-generation of intelligent communication systems. Compared to earlier versions, the new 5G wireless standard operates across a wider range of frequencies, which has raised aviation industry's concerns regarding safety and compatibility. For example, 5G systems operating with frequencies that are adjacent those used by radio altimeters could disrupt flight operations and navigation functions. This paper provides an overview of current research efforts assessing the 5G interference and its potential operational impact on altimeters. The work discusses the current stance of regulators and telecommunications operators worldwide on potential 5G interference with altimeters. The paper also compares the ongoing public consultations with key stakeholders globally regarding cellular systems' interference with altimeters. This work offers technical and policy recommendations to spectrum regulators and aviation authorities to inform the safe and efficient deployment of 5G spectra. This work identifies long-term solutions for achieving maximum 5G bands usability and ensuring compatibility among cellular technologies and aviation systems. • Aviation altimeters are highly susceptible to interference due to 5G mid-band. • Using directional 5G beams could be an interference mitigation solution. • Lack of definitive real-time data remains a barrier for interference estimation. • Regulations should be revised to reflect recent operational altimeter requirements. • Manufacturers need compliance with the altimeter's minimum operational standards. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is an innovation in technology. Continuous advancements based on the IoT cloud have revolutionized the lives of humans, and remote health monitoring of patients is no exception. The Telecare Medicine Information System (TMIS) allows physicians, other health care providers and patients to observe the medical data electronically. Therefore, security in remote medicine has always been a serious challenge. Recently, to make a secure communication system, biometrics-based schemes have played a crucial role in IoT, Wireless Sensor Networks (WSN), etc. are gaining popularity due to their authenticity and high security properties. Many key agreement schemes have been presented in this literature. These schemes are only for authorized access to medical services and initiate a session to negotiate a shared essential between users and servers. Recently, Xiong et al. and Mehmood et al. presented key exchange methods for healthcare applications that claimed these schemes provide greater privacy. However, we show that these schemes suffer from privacy issues and key compromise impersonation attacks. In this paper, to remove such restrictions, a novel scheme (ECKCI) based on Elliptic Curve Cryptography (ECC) with KCI resistance property was proposed. Furthermore, we demonstrate that the ECKCI not only overcomes problems such as key compromise impersonation attacks in previous protocols, but also resists all specific attacks. Finally, a suitable equilibrium between the performance and security of ECKCI in comparison with recently proposed protocols was obtained. Also, the simulation results with the Scyther and ProVerif tools show that the ECKCI is safe [ABSTRACT FROM AUTHOR]

Spatial Modulation(SM) and Orthogonal Frequency Division Multiplexing(OFDM) Multi-Mode Index Modulation (MM-OFDM-IM) techniques have significant advantages in Energy Efficiency(EE) and Spectral Efficiency(SE), respectively. The combination of multi-dimensional index modulation technology can apply multiple physical resources to meet the high demand for data transmission and system capacity in wireless communication systems. Therefore, SM and MM-OFDM-IM systems can be flexibly combined to construct an OFDM Multiple Mode Space Frequency Composite Index Modulation (MM-OFDM-SFCIM) based on space frequency combination. This system can retain the silent subcarriers in traditional subcarrier index modulation technique, expanding new composite coefficient dimensions and improving its SE and EE. Aiming at the complex characteristics of this system, this paper proposes a joint detection algorithm EL-REML (REML based on symbolic Energy and LLR) based on symbolic energy and log-likelihood. The simulation results show that the MM-OFDM-SFCIM system achieves about 30% improvement in SE compared to traditional space-frequency combination systems, and the EL-REML algorithm proposed in this system achieves a 3-4 dB improvement in BER (Bit Error Rate) compared to the LLR algorithm. Compared with traditional ML algorithm, this algorithm has lower computational complexity. [ABSTRACT FROM AUTHOR]

The proliferation of wireless technologies, particularly the advent of 5G networks, has ushered in transformative possibilities for enhancing vehicular communication systems, particularly in the context of autonomous driving. Leveraging sensory data and mapping information downloaded from base stations using I2V links, autonomous vehicles in these networks present the promise of enabling distant perceptual abilities essential to completing various tasks in a dynamic environment. However, the efficient down-link transmission of vehicular network data via base stations, often relying on spectrum sharing, presents a multifaceted challenge. This paper addresses the intricacies of spectrum allocation in vehicular networks, aiming to resolve the thorny issues of cross-station interference and coupling while adapting to the dynamic and evolving characteristics of the vehicular environment. A novel approach is suggested involving the utilization of a multi-agent option-critic reinforcement learning algorithm. This algorithm serves a dual purpose: firstly, it learns the most efficient way to allocate spectrum resources optimally. Secondly, it adapts to the ever-changing dynamics of the environment by learning various policy options tailored to different situations. Moreover, it identifies the conditions under which a switch between these policy options is warranted as the situation evolves. The proposed algorithm is structured in two layers, with the upper layer consisting of policy options that are shared across all agents, and the lower layer comprising intra-option policies executed in a distributed manner. Through experimentation, we showcase the superior spectrum efficiency and communication quality achieved by our approach. Specifically, our approach outperforms the baseline methods in terms of training average reward convergence stability and the transmission success rate. Control-variable experiments also reflect the better adaptability of the proposed method as the environmental conditions change, underscoring the significant potential of the proposed method in aiding successful down-link transmissions in vehicular networks. [ABSTRACT FROM AUTHOR]

As users can only make informed choices when the proposals being discussed are meaningful to them, enabling users to envision and make sense of those proposals is an essential element of all approaches to system design. The focus of this study is the conceptualization of a graphical authentication mechanism appropriate for ubiquitous environments. Therefore, the experiment presented in this paper uses the paper prototyping method is used to effectively simulate graphical authentication and distinguish the user preference between two system approaches in ubiquitous environments. Complementary, both a high fidelity paper and a mobile prototype is used in order to evaluate popular graphical authentication concepts which are based on separate cognitive functions: recall and recognition. This experiment uses a between group design where each participant evaluates a prototype for both authentication concepts in the same medium. The results of the study demonstrate that recognition-based graphical authentication mechanisms are more suitable for ubiquitous environments than recall-based systems. [ABSTRACT FROM AUTHOR]

In this paper, an artificial general perfect magnetic conductor (PMC) decoupling structure is proposed to improve the isolation between two-element closely spaced antenna arrays with an operating frequency around 2.4 GHz. This kind of PMC structure can effectively activate the in-phase coupling current and cancel the antiphase coupling current raised by the original perfect electric conductor (PEC) equivalent interface, thereby blocking the energy coupling from one antenna input port to another. The proposed design is composed of a transmission line and a lumped element in the neutral position of a pair of electrically small antennas. To validate the utility of this approach, we analyze the current/field distribution of this structure and the mode superposition mechanism in the present paper. The results show that, with a close center-to-center distance of 5 mm, the isolation between the arrays is improved from −5 dB to −20 dB at around 2.4 GHz. Furthermore, to validate the feature that this special in-phase coupling current distribution is insensitive to frequency, we analyze the decoupling performance in a frequency reconfiguration or a dual-frequencytwo-element antenna array. The decoupling feature emerges in the proposed structure over a larger frequency range (2.2–2.6 GHz) than the previous design. A sample of this two-element frequency reconfiguration antenna system is fabricated and measured in this paper. We also realized a dual-frequency antenna system with expected isolation. Through the above discussion, we can know that these decoupling geometrical parameters can be worked in the whole range of 2.2–2.6 GHz with the same decoupling structural parameters. Good performance and compact structures make the proposed structure suitable for mobile communication applications. [ABSTRACT FROM AUTHOR]

M2M is a concept and a general term for all technologies that enhance the communication and network capabilities of machines and equipment. It is a combination of different types of communication technologies. M2M enables all devices and users to share information, saving operation time and improving work efficiency. M2M is not a simple data transmission, but it is an intelligent and interactive communication between machines. Even if no real-time signal is sent, the machine will actively communicate according to the established program and select intelligently according to the obtained data. The communication system refers to the general term of the technology that completes the information transmission function. The modern communication system is mainly realized by the propagation of electromagnetic waves in free space or the transmission mechanism in the guiding medium. When the wavelength of the electromagnetic wave reaches the light wave range, such a telecommunication system is called an optical communication system, and the communication system in the other electromagnetic wave range is called an electromagnetic communication system, abbreviated as a telecommunication system. The purpose of this paper is to explore the study of wireless data sharing method for M2M mobile telecommunication systems in the 5G era. It is expected that the new algorithm will make the wireless resource allocation more reasonable and improve the resource utilization rate. The performance of the deterministic measurement matrix proposed in this paper is close to or even better than that of the random measurement matrix. The M-SP algorithm greatly improves the performance of the SP algorithm. The experimental results of this paper show that when the number of microbase stations is 10, the energy consumption of the direct algorithm is 175000 W, the energy consumption of the indirect algorithm is 350000 W, and the energy consumption of the direct algorithm is much smaller than that of the indirect algorithm. [ABSTRACT FROM AUTHOR]

The effect of additive noise on the channel state information (CSI) quality is a crucial issue in mobile communication systems. The adaptive subcarrier grouping (ASG) for sample matrix inversion (SMI) based minimum mean square error (MMSE) adaptive array has been previously proposed. However, this method needs to know the signal-to-noise ratio (SNR) in advance to set the threshold, perform grouping, and take the average, causing an insufficient number of signal samples. As a result, the ability to eliminate noise is limited. In this paper, we propose a new method based on data-aided weight calculation and the least mean square (LMS) algorithm without SNR information, which increases the number of samples. The decision results and initial weight are obtained by the SMI method with subcarrier grouping, and then the LMS method with subcarrier grouping is applied to reduce the channel estimation error as well as the amount of computation. Simulation results demonstrate that the proposed scheme is an efficient approach to improve Bit Error Rate (BER) performance under various Rician K factors. [ABSTRACT FROM AUTHOR]

Introduces a series of articles on multiple wireless and mobile access technologies

This paper is oriented to the credit investigation scenario of power grid supply chain enterprises and proposes a blockchain user credit assessment method based on improved Softmax regression in Power IoT. This method first designs a credit-rating mechanism that meets industry characteristics based on business needs. Second, it proposes a user credit evaluation model based on the blockchain architecture. Finally, the improved Softmax regression algorithm is used to train the proposed credit evaluation model, which effectively solves the credit rating. The multiclassification problem has achieved the goal of categorizing the credit rating of the enterprise. The simulation results show that the credit evaluation mechanism proposed in this paper can accurately evaluate the multisource credit data that lacks trust foundation and effectively realize the credit rating of power grid material supply chain enterprises. The credit evaluation mechanism proposed for Power IoT in this paper could have high potential for entity identity authentication and rating for securing mobile video communications. [ABSTRACT FROM AUTHOR]

Based on mobile edge computing and user perception technology, this paper analyzes and discusses the respective advantages and disadvantages of the important optimization models and mobile models in the animation art design, as well as the wireless block data transmission mechanism and protocol. In order to solve the problem that user mobility cannot be sensed, a content-centric mobile edge animation art design mechanism based on user mobility perception is proposed. This mechanism comprehensively calculates the centrality of users' perception of nodes, the idle rate of animation design, and the staying time of users in a small area. The mobile edge network controller integrates the information of each edge user's perception node, calculates the importance of each edge user's perception node and prioritizes it, and selects the appropriate content animation to design the user perception node according to the ranking result. Finally, various simulation or platform test experiments were carried out for all the design schemes in this paper, and the experimental results were analyzed. The simulation experiment results show that compared with the traditional animation design mechanism, the animation art design system effectively reduces the average number of hops for users to obtain content by up to 15.9%, improves the hit rate of edge user perception node animation design by at least 13.7%, and reduces the traffic entering the core network by up to 32.1%. According to the comparison results, the various designs in this work can successfully use sensor data to preclassify migration tasks in the mobile edge network environment. Compared with the latest block data transmission protocol, it has a significant performance improvement, reducing the data distribution delay by 34.8%, thereby helping to improve the overall efficiency of mobile edge computing. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the editor discusses various reports within the issue on topics including trustworthy operations for cellular networks, content leakage during video streaming, and trustworthy service evaluation .

Filter Bank Multicarrier(FBMC)is considered as one of the most standardized waveform for fifth generation (5G) mobile communication system application FBMC endures lot of nonlinear effects which occurs because of high Peak Average Power Ratio (PAPR). High value of PAPR due to the large dynamic range of multicarrier signal is one of the most significant issues in FBMC multicarrier based modulation technique. This paper presents one investigated PAPR reduction technique named as Selected Mapping (SLM) to minimize high PAPR by utilizing the complex signal divide into real and imaginary parts and then select minimum PAPR signal based on Modified Forest Optimization Algorithm (MFOA)to achieve good PAPR which can maintain the FBMC based system performance with a required Bit Error Rate (BER). The associated method was produced with the aim of optimize the phase factors so that the phase rotation operation is accomplished to minimize PAPR by fixing the MFOA into the conventional SLM. The simulation results demonstrate that the proposed technique gives better performance in terms of BER and PAPR compared to other SLM based optimization techniques. [ABSTRACT FROM AUTHOR]

Compared with railway communication service requirements on the mainline, requirements in hotspots such as stations and yards are more complicated in terms of service types as well as bandwidth, of which railway-dedicated mobile communication systems such as 5G-R facilitated with dedicated frequency support cannot meet the entire communication requirements. Therefore, other radio-communication technologies need to be adopted as a supplement, among which the mmWave communication system is a promising technology, especially for large bandwidth communication between train and trackside. However, there is a lack of evaluation of the 28 GHz mmWave channel characteristics for the railway marshaling yard scenario. In this paper, the railway marshaling yard mmWave propagation scenario is deeply analyzed and classified into three typical categories, based on which, a measurement campaign is conducted using an SDR channel sounding system equipped with a 28 GHz mmWave phased-array antenna. A self-developed software under the LabVIEW platform is used to derive the channel parameters. Conclusions on the relationship between the parameters of MPC numbers, time-spread, and received power and position, as well as the impact of typical obstructions such as the Catenary, adjacent locomotives, and buildings are drawn. The statistical results and conclusions of this paper are helpful for facilitating the design and performance evaluation of future mmWave communication systems for railway marshaling yards and can also be further extended and applied to the research of mmWave utilization in 6G and other future communication technologies for more scenarios. [ABSTRACT FROM AUTHOR]

The paper deals with a possible SOA based m-healthcare online system with secure mobile communication between patients and medical professionals with medical and insurance organizations. An example of an Android-based secure mobile client application is presented which can be used in the described secure m-healthcare model and it is experimentally evaluated. In the paper, we focus on possible optimization of cryptographic algorithms implemented in the secure Android mobile client application. The presented experimental results justify that security operations related to X.509v3 digital certificate generation and XML/WSS digital signature creation/veriffication are feasible on some current smart phones and justify the use of the proposed optimization techniques for implemented cryptographic algorithms. [ABSTRACT FROM AUTHOR]

Wireless channel characterization and modeling is the foundation of vehicular communication systems. However, most of the existing researches on vehicle-to-vehicle (V2V) channel are aimed at the traditional scenarios such as urban and suburban, and the researches on some complicated vehicular scenarios are insufficient. For example, little attention is paid to viaduct, tunnel, and cutting scenarios in vehicular communications, and these complex scenarios often become the high-incidence area of communication interruption, and then affect the overall performance of the vehicular communication system due to the bad and unique channel characteristics. In this paper, to fill this gap, time-varying characteristics of V2V channels in viaduct, tunnel, and cutting scenarios are investigated. Specifically, based on 5.9 GHz channel measurements, channel non-stationarity is quantitatively evaluated and compared. Further, a detailed analysis of time-varying power and delay of multipath components (MPCs) is presented. Based on the obtained results, the mechanism of physical environment affecting channel characteristics is analyzed, and the impacts of vehicular scenarios are quantified. Besides, the impacts of scenarios on the spatial distribution of MPCs are investigated. The angular distributions of MPCs in the three typical V2V scenarios are revealed, and the corresponding statistical characteristics are presented. Moreover, the characteristics of MPC clusters in different scenarios are further quantified and analyzed, such as MPC number in each cluster and cluster lifetime. It is revealed that the non-stationarity of the V2V channel originates from the birth-death process of MPC clusters, and the birth-death process is modeled statistically. The results in the paper show the V2V channel propagation mechanism and can be used for the design of vehicular communication systems in complicated scenarios. [ABSTRACT FROM AUTHOR]

Radio signal recognition has a wide application in future communication systems and the vehicular communication, whose core is the extraction of signal features such as electromagnetic fingerprints. With the rapid development of artificial intelligence technology, deep learning has made amazing breakthroughs in image recognition, speech recognition and other fields. Deep learning is applied to electromagnetic fingerprint extraction in this paper. Firstly, thousands of the downlink aircraft communications addressing and reporting system (ACARS) signals used for communication between civil aircraft and airport tower are collected and generated. Then a pre-transformation network suitable for electromagnetic signals is constructed to convert one-dimensional signals into two-dimensional feature maps, and afterwards the feature maps are input into the convolutional neural network (CNN) for classification. By adopting the attention modules, the classification results were improved by a few percentage points over the baseline with a little cost. The method proposed in this paper achieves an accuracy rate of 94.1% and can obtain the aircraft type in a shorter time than traditional method. Moreover, the robustness of the proposed model in response to additive Gaussian white noise (AWGN) and phase deviation is studied and tested. [ABSTRACT FROM AUTHOR]

This paper proposes a hierarchical error recovery method for the hybrid mobile broadcast/communication networks. The mobile broadcast network (e.g., DVB-T/H, T-DMB) transmits the base forward error correction (FEC) and the multimedia content at the same time for the error recovery. However, the occurrence of errors is different due to the receiving environment of the individual mobile broadcast network, and not all the base FECs can recover errors. The server retransmits the enhanced-FEC (E-FEC) to a terminal through the individual mobile communication network and a terminal can try to recover the packet with errors which the base FEC cannot recover. If there are more retransmitted source data to a user, the overhead of a user and the communication network will increase because the individual mobile communication is a subscription-based network. Therefore, this paper proposes a hierarchical error recovery method, and the E-FEC with higher channel coding rate than base FEC is generated and transmitted. The proposed method in this paper transmits only the redundancy data for the error recovery when errors occur, and reduces the resource by 50%–80% compared with the retransmission of the source. If the source bit rate is 800 kbps, for instance, the packet error ratio is 10%, and if a user watches a broadcast content for one hour, the amount of retransmitted data is 80 kbps × 3600 = 36 MBytes, but that of the proposed method in this paper is 7.2–18 MBytes. [ABSTRACT FROM AUTHOR]

An introduction is presented to the article in this issue on mobile communications and computer in challenged environments including "Autonomous aggregation in location aware ad hoc wireless networks," "A process calculus for energy-aware multicast communications of mobile ad hoc networks" and "Discovery and provision of content in vehicular networks."

Purpose — The main purpose of this paper is to analyze which standard/technology will win the 3G mobile markets. In addition, two sub topics are examined. First, which kind of victory will it be — will one technological solution be all-dominating or is co-existence more likely? Second, which are the most decisive factors in the battle between the different standards — which roles do respectively technology path-dependence, network effects and strategic concerns play? Design/methodology/approach — The approach taken in the paper is to examine the different kinds of stakeholders — in this field, first and foremost, equipment manufacturers, network operators, policy makers/administrators and end users; to analyze how such stakeholders are intervening in the different relevant steps — technology development, technology deployment and technology take-up — and to analyze these issues from different angles — technology, markets and economy, policy and regulation, and other social aspects. Findings — The paper concludes that WCDMA will dominate the markets, but that there will be a co-existence of different solutions — also inside individual countries where more than one solution is implemented. Originality/value — The paper is based on the understanding that a vast array of different factors in a complex dynamic environment goes into the determination of the outcome of such standardization games. However, the battle between 3G standards has already reached a level, where relatively certain predictions can be made. And, the paper contributes with a methodologically based discussion concerning the outcome of the battle between 3G standards. [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) technology is widely used in integrated radar and communication systems (IRCSs). Moreover, index modulation (IM) is a reliable OFDM transmission scheme in the field of communication, which transmits information by arranging several distinguishable constellations. In this paper, we propose a sparse reconstruction-based joint signal processing scheme for integrated MIMO-OFDM-IM systems. Combining the advantages of MIMO and OFDM-IM technologies, the integrated MIMO-OFDM-IM signal design is realized through the reasonable allocation of bits and subcarriers, resulting in better intercarrier interference (ICI) resistance and a higher transmission efficiency. Taking advantage of the sparseness of OFDM-IM, an improved target parameter estimation method based on sparse signal reconstruction is explored to eliminate the influence of empty subcarriers on the matched filtering at the receiver side. In addition, an improved sequential Monte Carlo signal detection method is introduced to realize the efficient detection of communication signals. The simulation results show that the proposed integrated system is 5 dB lower in the peak sidelobe ratio (PSLR) and 1.5 × 10 5 lower in the number of complex multiplications than the latest MIMO-OFDM system and can achieve almost the same parameter estimation performance. With the same spectral efficiency, it has a lower bit error rate (BER) than existing methods. [ABSTRACT FROM AUTHOR]

The metasurface is a promising technology that can help next-generation wireless communication systems not only improve the signal-to-noise ratio (SNR), but also increase security and mitigate interference. Further, introducing dual polarization (DP) in a metasurface can enhance its capabilities with polarization diversity, polarization multiplexing, and polarization-switched modulation. In this paper, we study a DP-metasurface-assisted single-user wireless communication system and propose a novel scheme that can improve the spectral efficiency (SE) and bit-error-rate (BER) performance compared to those of conventional schemes by exploiting the orthogonal property of dual-polarized waves. We employ the DP metasurface to increase the SNR at the receiver and create a specific phase difference between the polarized signals by controlling the transmit precoder and the phases of the metasurface reflecting elements representing some modulated bits. At the receiver, we use the recovered phase information to realign the modulated symbols in both polarizations, which are then added coherently. The simulation results demonstrate that the proposed scheme achieves significantly higher SE and BER performance than those of some closely related works. [ABSTRACT FROM AUTHOR]

The development of the fifth-generation (5G) mobile communication systems has entered the commercialization stage. 5G has a high data rate, low latency, and high reliability that can meet the basic demands of most industries and daily life, such as the Internet of Things (IoT), intelligent transportation systems, positioning, and navigation. The continuous progress and development of society have aroused wide concern. Positioning accuracy is the core demand for the applications, especially in complex environments such as airports, warehouses, supermarkets, and basements. However, many factors also affect the accuracy of positioning in those environments, for example, multipath effects, non-line-of-sight, and clock synchronization errors. This paper provides a comprehensive review of the existing works about positioning for the future wireless network and discusses its key techniques and algorithms, as well as the current development and future directions. We first outline the current traditional positioning technologies and algorithms, which are discussed and analyzed with the relevant literature. In addition, we also discuss application scenarios for wireless localization. By comparing different positioning systems, the challenges and future development directions of existing wireless positioning systems are prospected. [ABSTRACT FROM AUTHOR]

Hybrid beamforming (HBF) has been regarded as one of the most promising technologies in millimeter Wave (mmWave) communication systems. In order to guarantee the communication quality in non-line-of-sight (NLOS) scenarios, joint HBF design for the mmWave amplify-and-forward (AF) relay communication system is studied in this paper. The ideal case is first considered where the mmWave half-duplex (HD) AF relay system operates with channel state information (CSI) accurately known. In order to tackle the non-convex problem, a manifold optimization (MO)-based alternating optimization algorithm is proposed, where an optimization problem containing only constant modulus constraints in Euclidean space can be converted to an unconstrained optimization problem in a Riemann manifold. Furthermore, considering more practical cases with estimation errors of CSI, we investigate the robust joint HBF design with the system operating in full-duplex (FD) mode to obtain higher spectral efficiency (SE). A null-space projection (NP) based self-interference cancellation (SIC) algorithm is developed to attenuate the self-interference (SI). Different from the traditional SI suppression algorithm, there's no limit on the number of RF chains. Numerical results reveal that our proposed algorithms has a good convergence and can effectively deal with the influence of different CSI estimation errors. A significant performance improvement can be achieved in contrast with other approaches. [ABSTRACT FROM AUTHOR]

This paper examines the communication difficulties encountered in cross-media wireless optical transmission through simulated research on the utilization of orthogonal time and frequency space (OTFS) modulation technology. Our analysis and comparison demonstrate that OTFS significantly improves the reliability and throughput of data transmission in intricate multipath channel settings. In contrast to conventional orthogonal frequency division multiplexing (OFDM) technology, OTFS displays better resilience and transmission effectiveness. We foresee additional enhancements and progress in OTFS technology to present a sturdier and more efficient resolution for wireless communication, thereby providing valuable perspectives and encouragement for associated research initiatives. Our results underscore the capability of OTFS technology to transform wireless communication systems in demanding multipath channel conditions. [ABSTRACT FROM AUTHOR]

With the rapid development of Internet of Things (IoT) technology, the number of IoT users is growing year after year. IoT will become a part of our daily lives, so it is likely that the security of these devices will be an important issue in the future. Quantum computing is maturing, and the security threat associated with quantum computing will be faced in the transmissions of IoT devices, which mainly use wireless communication technologies. Therefore, to ensure the protection of transmitted data, a cryptographic algorithm that is efficient in defeating quantum computer attacks needs to be developed. In this paper, we propose a device authentication and secure communication system with post-quantum cryptography (PQC) for AIoT environments using the NTRU and Falcon signature mechanism, which can resist quantum computer attacks and be used in AIoT environments to effectively protect the confidentiality, integrity, and non-repudiation of transmitted data. We also used Raspberry Pi to simulate AIoT devices for implementation. [ABSTRACT FROM AUTHOR]

In the evolving landscape of Industry 4.0, the integration of advanced wireless technologies into manufacturing processes holds the promise of unprecedented connectivity and efficiency. In particular, the data transmission in a heavy industry environment needs stable connectivity with mobile operators. This paper deals with the performance study of 4G and 5G mobile signal coverage within a complex factory environment. For this purpose, a cost-effective and portable measurement setup was realized and used to provide long-term measurement campaigns monitoring and recording several key parameter indicators (KPIs) in 4G/5G downlink and upload. To support the reproducibility of the provided study and other research activities, the measured dataset is publicly available for download. Among others findings, the obtained results show how the performance of 4G/5G is influenced by a heavy industry environment and of the time of day on the network load. [ABSTRACT FROM AUTHOR]

This paper presented the high performance signature of transceiver fiber system based on cascade uniform fiber Bragg grating devices. This model has a data rate of 20 Gb/s extended along optical fiber length of 10 km that amplified with an optical EDFA amplifiers at 5 m length. The presented study clarified max. Q of 20.33 compared to the previous models at the value of 8.66. The electrical visualizer measured the total power at the receiver that is 9.564 dBm at the previous model and 23.347 dBm at the presented model. Therefore the total power at the receiver increased by 2.44 times at the presented model and the max. Q also upgraded by 2.96 times at the presented model. [ABSTRACT FROM AUTHOR]

Orthogonal frequency-division multiplexing (OFDM) chirp waveforms are an attractive candidate to be a dual-function signal scheme for the joint radar and communication systems. OFDM chirp signals can not only be employed to transmit communication data through classic phase modulation, but also can perform radar detection by applying linear frequency modulation for subcarriers. However, the performance of the OFDM chirp communication system under the phase noise environment still remains uninvestigated. This paper tries to discuss the influence of phase noise on OFDM chirp communication systems and proposes effective phase noise estimation and compensation methods. We find that the phase noise effect on OFDM chirp communication systems consists of a common phase error (CPE) and an inter-carrier interference (ICI). If not compensated, the performance of the dual-function systems can be seriously degraded. In particular, an exact expression for the signal-plus-interference to noise ratio (SINR) for the OFDM chirp communication system is derived and some critical parameters are analyzed to exhibit the phase noise effects on system performance. Moreover, two low-complexity estimation approaches, maximum likelihood (ML) and linear minimum mean square error (LMMSE), as well as two compensation approaches, the de-correlation and cancellation algorithms, are respectively utilized to eliminate the phase noise impairment. Finally, the phase noise effects and the effectiveness of the compensation approach are verified by extensive numerical results. [ABSTRACT FROM AUTHOR]

The advent of intelligent reflecting surface (IRS) technology has revolutionized the landscape of wireless communication systems, offering promising opportunities for enhancing the performance of Internet of Things (IoT) applications. This paper presents a comprehensive performance evaluation of multi-agent IoT monitoring systems leveraging IRS technology. We focus on three criteria for selecting IRS units and assess the impact on system performance. Specifically, we analyze the system performance by deriving an outage probability expression for each criterion. Our study begins by introducing the concept of IRS and its role in IoT monitoring. We then present three IRS unit selection criteria: optimal selection (OS), partial selection (PS), and random selection (RS). For each criterion, we mathematically model and analyze the system outage probability, shedding light on the reliability and connectivity of IoT devices. The outage probability expressions derived in this work offer valuable insights into the trade-offs associated with IRS unit selection criteria in the context of IoT monitoring. Additionally, our findings contribute to the optimization of multi-agent IoT monitoring systems, enabling improved communication performance and enhanced reliability. [ABSTRACT FROM AUTHOR]

Designing antennas for vehicular communication systems presents several unique challenges due to the dynamic nature of vehicular environments, mobility, and the need for reliable connectivity. A wider bandwidth is a critical requirement of vehicular antennas. In this paper, a super-wideband FR4 epoxy-based low-cost meander line patch antenna is designed for fifth-generation (5G) vehicular mobile frequency applications. The proposed antenna is excited through a microstrip feedline on top of the substrate with a continuous ground plane. The meander line is implemented through a theoretical formula to cover upper-5G frequency range 1 (FR1) and frequency range 2 (FR2). The proposed antenna has 7.5 dBi peak gain when operated at 28 GHz. The simulated bandwidth ratio (BWR) is 9.09:1 for a −10 dB reflection coefficient covering a 53.4 GHz (6.6 GHz to 60 GHz) frequency range. The proposed antenna has a linear meander line planar structure, occupies a small area of 34 mm × 20 mm × 1.6 mm, and satisfies the bandwidth requirements of 5G millimeter-wave and sub-bands of the sixth generation for vehicular applications. [ABSTRACT FROM AUTHOR]