Mobile Communication Environment Research Articles

RIS-assisted Optical Receiver Model and Reflected Angle Optimization for Visible Light Communication in Mobile Environment

RIS-assisted Optical Receiver Model and Reflected Angle Optimization for Visible Light Communication in Mobile Environment

A Study on the Implementation of a Network Function for Real-time False Base Station Detection for the Next Generation Mobile Communication Environment

The threat posed by false base stations remains pertinent across the 4G, 5G, and forthcoming 6G generations of mobile communication. In response, this paper introduces a real-time detection method for false base stations employing two approaches: machine learning and specification-based. Utilizing the UERANSIM open 5G RAN (Radio-Access Network) test platform, we assess the feasibility and practicality of applying these techniques within a 5G network environment. Emulating real-world 5G conditions, we implement a functional split in the 5G base station and deploy the False Base Station Detection Function (FDF) as a 5G NF (Network Function) within the CU (Central Unit). This setup enables real-time detection seamlessly integrated into the network. Experimental results indicate that specification-based detection outperforms machine learning, achieving a detection accuracy of 99.6% compared to 96.75% for the highest-performing machine learning model XGBoost. Furthermore, specification-based detection demonstrates superior efficiency, with CPU usage of 1.2% and memory usage of 16.12MB, compared to 1.6% CPU usage and 182.4MB memory usage for machine learning on average. Consequently, the implementation of specification-based detection using the proposed method emerges as the most effective technique in the 5G environment.

QR- CODES: THEIR CREATION AND USAGE AT THE ENGLISH LANGUAGE LESSON

The article reveals the essence of such concepts as mobile technologies, mobile learning, BYOD technology, QR-code. It is considered the specificity of the QR-code and the possibilities of its use in educational activities. It is noted that the technology of creation of QR-codes and recognition can be attributed to the elements of the mobile information and communication environment. The advantages and disadvantages of using QR-codes and the form of organization of educational activities are described. The research of modern scientists on the peculiarities of the implementation of the QR-codes in the educational process has been analyzed. The article provides an online resource that generates QR-codes. On the example of one of them, the peculiarities of using the resource and the sequence of stages of code generation are described. It is proposed an algorithm for scanning QR-code using camera of a mobile gadget, as well as a special application by pointing the camera at the image of the code and reading the information. It is mentioned that Internet resources for creating QR-codes are free, so anyone can create them using a special program, thus simplifying the learning process, which involves constant processing and analysis of certain information. Examples of the usage of QR-codes in teaching English are given: conducting quests, games, quizzes, polls and checking students’ knowledge through testing; conducting interesting online tours of world museums; the use of interesting and educational video files for a better understanding of the content learned during classes. It has been established that the usage of QR-codes in the educational process activates the educational activities among students, promotes quick and easy information searching, increases the motivation of students for studying, expands their horizons, provides an opportunity to improve the educational process, guarantees the accessibility and effectiveness of education and the preparation of the young generation for life in information environment.

Transmit Antenna Selection Based on SNR prediction in TDD Systems Using Convolutional Neural Network

This paper proposes a method for predicting future signal-to-noise ratio (SNR) in a time-division-duplexing (TDD) mobile communication environments using a convolutional neural network (CNN). The communication system uses multiple receive antennas and transmit using only one or two antennas among them. A CNN model is proposed to predict the SNR at a future transmission time based on past SNRs received from multiple antennas. The probability of reception at a certain is set to 10-100%. In case that SNR cannot be measured due to the absence of reception, linear interpolation is performed using two adjacent recorded SNRs. If even two adjacent SNRs do not exist, the SNR is set to 0dB. Comparing the predicted SNRs at multiple antennas, the antenna with the highest SNR value is selected for future transmission. To verify antenna selection accuracy, computer simulation is conducted. The simulation results substantiate the superiority of the proposed method over conventional method in single antenna selection. Regarding multi-antenna selection, the proposed method demonstrates diminished accuracy relative to conventional methods at lower speeds. Nevertheless, a comprehensive evaluation considering the root mean square error (RMSE) demonstrates the overall superiority of the proposed method across all speeds.

IEEE 802.15.4g/4x-Based Orthogonal Frequency-Division Multiplexing Transmission Scheme for Wide-Area and Mobile IoT Communication Systems

Radio communication systems using the frequency-shift keying (FSK) scheme standardized by the IEEE 802.15.4g standard can realize low-power consumption and highly reliable communications and are mainly adopted for smart metering as part of the Internet of Things (IoT). However, smart metering has recently broadened its application expectations, with broadband and long-distance communications now required. To fulfill these requirements, orthogonal frequency-division multiplexing (OFDM) has been incorporated into the IEEE 802.15.4g and 802.15.4x standards. However, comprehensive transmission performance analysis of OFDM under static and multipath fading environments has not been conducted. In this article, we first evaluated the packet error rate (PER) of OFDM assuming fixed communications using computer simulations. We then evaluated the transmission distance of OFDM and showed that OFDM can communicate at transmission distances up to 3.0 times longer than those specified in IEEE 802.15.4g FSK. Next, the PER in a mobile communication environment was evaluated using computer simulations. When only the long training field (LTF) was used to estimate multipath radio channels, the required PER of 10% was not achieved, even in a mobile communication environment at a speed of several km/h. To solve this problem, we proposed a receiving scheme which included a new channel estimation scheme. This scheme successively utilized not only the LTF but also pilot signals inserted into the transmitter to estimate radio propagation characteristics. Computer simulation results showed that the required PER was achieved even in a mobile communication environment at 30–40 km/h by using the proposed scheme.

An MIH-enhanced fully distributed mobility management (MF-DMM) solution for real and non-real time CVBR traffic classes in mobile internet

The integration of wireless access networks has progressed rapidly in recent years. Within the mobile communication environment, the operator provides multiple interface options for the mobile node (MN) to switch its connection to any access network during mobility to achieve the quality of service (QoS) for various traffic classes. The conventional centralised mobility management (CMM) scheme lacks reliability, dynamic anchoring and a single point of failure. This stimulates the distributed mobility management (DMM) scheme to handle mobility at the access network rather in a centralised manner. Therefore, in this paper, an IEEE 802.21 media independent handover (MIH) enhanced fully DMM (MF-DMM) solution is proposed for real- and non-real-time constant and variable bit rate (CVBR) traffic classes for mobile internetworking applications. The performance factors of handover delay, packet loss rate, throughput and signalling overheads are compared with the existing CMM scheme. The simulation results prove that the presented MF-DMM technique considerably reduces the handover delay while switching to different access technologies and, thus, achieves seamless connection by managing mobile internet protocol (IP) traffic locally.

Parents’ literacy on mobile advertising aimed at children: a cross - cultural approach

PurposeThe use of mobile devices by children and adolescents is increasing significantly; therefore, it is relevant to research the level of advertising literacy (AL) of parents who act as mediators between children and mobile advertising. This study aims to explore the conceptual, moral and attitudinal dimensions of AL and its relationship with different styles of parental control.Design/methodology/approachA cross-sectional survey was applied simultaneously to a sample of parents with children between 5 and 16 years old in three Spanish-speaking countries: Mexico, Spain and Colombia. Participants from the three countries were recruited via online social media networks and were asked to fill in an online survey. A questionnaire, which has been adapted from previous literature to suit the mobile advertising context and the population of interest, was designed. Cross-country samples of varying sizes, with a predetermined quota of 200 participants for each country, were used. The total sample consisted of 1,454 participants.FindingsFour factors of mobile AL were found, which, to a greater extent, correspond to the dimensions of AL proposed in the literature. The following are the dimensions that were identified: cognitive, moral, attitudinal and an emerging factor is known as “children’s perceived mobile AL.” Differences in parents’ perceived knowledge of mobile advertising, parental control styles and AL levels in the three countries were identified. Parents with an authoritative style were identified to have more knowledge than those with an indulgent style. Differences were also identified between countries concerning the amount of exposure that children have to mobile advertising, while no significant differences were found in the moral dimension.Practical implicationsMarketing practitioners and public policymakers must consider that parents differ in some dimensions of AL. Parents also seem to lack adequate knowledge about the advertising tools available to announcers that affect children and adolescents in a mobile communication environment. Therefore, government agencies should consider developing mobile digital media literacy programs for parents.Originality/valueThis paper explores the dimensions of AL applied to the mobile context and identifies the level of parental mobile AL in three Spanish-speaking countries, as well as the differences between these sub-samples concerning parental mobile AL profiles and parental control styles, thus expanding the literature on AL with a cross-cultural approach.

CP-ABE-Based Secure and Verifiable Data Deletion in Cloud

Cloud data, the ownership of which is separated from their administration, usually contain users’ private information, especially in the fifth-generation mobile communication (5G) environment, because of collecting data from various smart mobile devices inevitably containing personal information. If it is not securely deleted in time or the result of data deletion cannot be verified after their expiration, this will lead to serious issues, such as unauthorized access and data privacy disclosure. Therefore, this affects the security of cloud data and hinders the development of cloud computing services seriously. In this paper, we propose a novel secure data deletion and verification (SDVC) scheme based on CP-ABE to achieve fine-grained secure data deletion and deletion verification for cloud data. Based on the idea of access policy in CP-ABE, we construct an attribute association tree to implement fast revoking attribute and reencrypting key to achieve fine-grained control of secure key deletion. Furthermore, we build a rule transposition algorithm to generate random data blocks and combine the overwriting technology with the Merkle hash tree to implement secure ciphertext deletion and generate a validator, which is then used to verify the result of data deletion. We prove the security of the SDVC scheme under the standard model and verify the correctness and effectiveness of the SDVC scheme through theoretical analysis and ample simulation experiment results.

MIMO Systems in a Composite Fading and Generalized Noise Scenario: A Review

Multiple-Input Multiple-Output (MIMO) systems have been endorsed to enable future wireless communication requirements. The efficient system designing appeals an appropriate channel model that considers all the dominating effects of the wireless environment. Therefore, some complex or less analytically acquiescent composite channel models have been proposed typically for Single-Input Single-Output (SISO) systems. These models are explicitly employed for mobile applications, though, we need a specific study of a model for the MIMO system which can deal with radar clutters and different indoor/outdoor and mobile communication environments. Subsequently, the performance enhancement of the MIMO system is also required in such a scenario. The system performance enhancement can be examined by low error rate and high capacity using spatial diversity and spatial multiplexing respectively. Furthermore, for a more feasible and practical system modeling, we require a generalized noise model along with a composite channel model. Thus, all the patents related to MIMO channel models are revised to achieve the nearoptimal system performance in a real-world scenario. This review paper offers the methods to improve MIMO system performance in less and severe fading as well as shadowing environment and focused on a composite Weibull-gamma fading model. The development is the collective effects of selecting the appropriate channel models, spatial multiplexing/detection, and spatial diversity techniques both at the transmitter and the receivers in the presence of arbitrary noise.

Detecting Colluding Inter-App Communication in Mobile Environment

The increase in computing capabilities of mobile devices has, in the last few years, made possible a plethora of complex operations performed from smartphones and tablets end users, for instance, from a bank transfer to the full management of home automation. Clearly, in this context, the detection of malicious applications is a critical and challenging task, especially considering that the user is often totally unaware of the behavior of the applications installed on their device. In this paper, we propose a method to detect inter-app communication i.e., a colluding communication between different applications with data support to silently exfiltrate sensitive and private information. We based the proposed method on model checking, by representing Android applications in terms of automata and by proposing a set of logic properties to reduce the number of comparisons and a set of logic properties automatically generated for detecting colluding applications. We evaluated the proposed method on a set of 1092 Android applications, including different colluding attacks, by obtaining an accuracy of 1, showing the effectiveness of the proposed method.

Accurate Variable-Order Approximations to the Sum of α – μ Variates With Application to MIMO Systems

Sum of fading signals arises in several communication applications such as maximal-ratio combining (MRC) used in multiple antenna systems and eliminating the inter-symbol interference in high speed wireless networks. The exact formulation of the statistics of the sum is known to be very complicated. This article presents two simple closed-form approximations to the probability density function (PDF) and cumulative distribution function (CDF) of the sum of $\alpha -\mu $ variates, resembling an urban mobile communication environment. By direct integration, it is demonstrated that the PDF of the sum of $\alpha -\mu $ random variables can be approximated by a weighted sum of few identical $\alpha -\mu $ distributions including order one coefficients. The proposed approximations are of variable-order to achieve the desired accuracy and also have specific parameters using which, multiple-input multiple-output (MIMO) diversity systems can be explicitly analyzed as simply as a single-input single-output (SISO) system. In addition, a MIMO wireless system utilizing orthogonal space-time block coding technique (OSTBC-MIMO) in an $\alpha -\mu $ frequency nonselective fading environment is analyzed, and expressions for outage probability (OP) and bit error rate (BER) of digital binary modulations as well as the capacity are obtained. Moreover, the asymptotic OP and BER expressions are derived from the declared approximate expressions. The asymptotic OP and BER performances clearly indicate a diversity order equal to the product of the $\frac {\alpha }{2}$ parameter, the $\mu $ parameter, the number of transmit antennas and the number of receive antennas. Analytical results are verified by simulation.

A multi-level AI-based scheduler to increase adaptiveness in time-constrained mobile communication environments

Scheduling is one of the classic problems in real-time adaptive systems. Due to the complex nature of these applications, the implementation of some sort of run-time intelligence is required, in order to build intelligent systems capable of operating adequately in dynamic environments. The incorporation of artificial intelligence planning techniques in a real-time scenario allows a timely reaction to external and internal events. In this work, a layered architecture integrating real-time scheduling at the bottom level and artificial intelligence planning techniques at the top level has been designed, to implement a multi-level scheduler with the capability to perform effectively in this kind of situation. This multi-level scheduler has been implemented and evaluated in a simulated information access system destined to broadcast information to mobile users in a time-constrained communication environment, modeling mobile users’ realistic information access patterns. Results show that the incorporation of artificial intelligence planning improves the overall performance, adaptiveness, and responsiveness with respect to the non-AI-based scheduler version of the system.

Channel modelling for vehicle‐to‐vehicle MIMO communications in geometrical rectangular tunnel scenarios

This study presents a multiple-input multiple-output (MIMO) statistical channel model for vehicle-to-vehicle (V2V) line-of-sight (LOS) and non-LOS mobile communication system in a rectangular tunnel environment. In order to improve the V2V communication system performance, the authors introduced the elevation and azimuth angles in three-dimensional modelling based on the original literature. In the proposed reference channel model, the single-bounced scattering propagation path of electromagnetic signals is considered and it is assumed that the scatterers are randomly distributed on the rectangular tunnel wall. Starting from the statistical physical channel model, the time-variant transfer functions are derived. Thereafter, the analytical expressions of the space–time–frequency cross-correlation function, the space cross-correlation function, the temporal autocorrelation function, the frequency correlation function, and MIMO channel capacity are derived. The influence of model parameters on the performance of the V2V communication system is also analysed. This work provides an innovative approach to channel modelling in a rectangular tunnel mobile communication environment.

Parameter Adaptation and Situation Awareness of LTE-R Handover for High-Speed Railway Communication

In the evolution of railway mobile communications from Long Term Evolution for Railway ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LTE-R</i> ) to the future 5th Generation Wireless System ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5G</i> ), the rapid increase in the number of low-power base station nodes along the railway has brought more frequent handovers. The current handover parameter selection mechanism often relies on the on-site measured results in a limited number of discrete scenarios. It cannot deal with the continuous changing characteristics of the high-speed railway mobile communication environment, which leads to a serious lack of accuracy, adaptability and intelligence. This article hopes to construct a parameter-adaptive handover mechanism suitable for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5G</i> in the high-speed railway dedicated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LTE-R</i> communication system. The mechanism first uses the interaction of Temporal-Difference( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TD</i> )-learning-based reinforced agents to obtain high-speed railway handover performance and network performance in different combinations of speeds and handover parameters, and continuously updates the accumulated rewards used to target optimization, obtaining a Discrete TD value cube with closely related handover performance. Further, based on the Discrete TD value cube, we use the approximation function method for the completion of “continuous” situation of handover parameter selection, and construct a continuous TD value cube and the corresponding performance cubes. Our experimental results prove that TD learning agents with function approximation can accurately estimate and predict the handover performance and network performance of state combinations with different speeds and handover parameters, and further show that the handover parameter adaptation mechanism based on the Inference ability can find the optimal handover parameters to improve the handover performance and network performance.

Iterative Joint Channel Estimation, User Activity Tracking, and Data Detection for FTN-NOMA Systems Supporting Random Access

Given the requirements of increased data rate and massive connectivity in the Internet-of-things (IoT) applications of the fifth-generation communication systems (5G), non-orthogonal multiple access (NOMA) was shown to be capable of supporting more users than OMA. As a further potential enhancement, the faster-than-Nyquist (FTN) signaling is also capable of increasing the symbol rate. Since NOMA and FTN signaling impose non-orthogonalities from different perspectives, it is possible to achieve further increased spectral efficiency by exploiting both. Hence we investigate the FTN-NOMA uplink in the context of random access. Although random access schemes reduce the signaling overheads as well as latency, they require the base station to identify active users before performing data detection. As both inter-symbol and inter-user interferences exist, performing optimal detection requires a prohibitively high complexity. Moreover, in typical mobile communication environments, the channel envelope of users fluctuates violently, which imposes challenges on the receiver design. To tackle this problem, we propose a joint user activity tracking and data detection algorithm based on the factor graph framework, which relies on a sophisticated amalgam of expectation maximization (EM) and hybrid message passing algorithms. The complexity of the algorithm advocated only increases linearly with the number of active users. Our simulation results show that the proposed algorithm is effective in tracking user activity and detecting data symbols in dynamic random access systems.

An effective hyper-dense deployment algorithm via search economics

Developing an effective strategy for deploying base stations of a mobile communication environment has been a critical issue for years because it typically needs to take into account several conflict factors, such as coverage ratio and interference. Since 5G cellular services are expected to be commercially available in 2020, a “good deployment strategy” for the hyper-dense deployment problem (HDDP) has attracted the attention of researchers from different disciplines in recent years. To enhance the performance of a 5G mobile communication environment, an effective search algorithm for solving the HDDP, called search economics for hyper-dense deployment problem (SE-HDDP), is presented in this paper. A distinctive feature of the proposed algorithm is that it divides the search space into a set of subspaces and dynamically allocates the computing resources to these subspaces based on their potentials during the convergence process. The simulation results show that the proposed algorithm is able to find a better result of HDDP for a 5G mobile communication environment than all the other metaheuristic and rule-based algorithms compared in this paper.

Mobil Flört Uygulaması Wapa Hakkında Bir Netnografi Çalışması

Bu arastirmada mobil flort uygulamalarinda (MFU) cinsiyet performaslari ve iletisim bicimleri queer kuram ve netnografi yontemi ile incelenmistir. Arastirma Turkiye’deki Wapa kullanicilari ile gerceklestirilmistir. Wapa lezbiyenleri hedef alan populer, konum bazli ve gercek zamanli bir mobil flort uygulamasidir. Bu calismada Wapa kullanicilarinin profillerinde kendilerini tanitirken kullandiklari anlatilar incelenmekte ve cevrimici mulakatlar araciligiyla elde edilen kullanici deneyimlerine odaklanilmaktadir. Arastirma bulgulari bir mobil iletisim ortaminda erkek ve kadinlarin yeniden urettigi maskulenligini ortaya cikararak iletisim, teknoloji ve cinsiyet calismalariyla ilgili literature katkida bulunmaktadir. Arastirma sonunda MFU teknolojisinin kullanicilara yas araligi, cografi yakinlik ve cinsel yonelim gibi secenekler sunmasina karsin; mobil ortamin ayni zamanda queer kimlikler hakkindaki kliseleri yeniden ureten ve dolasima sokan bir alan oldugu saptanmistir.

An Effective Search Algorithm for Hyper-Dense Deployment Problem of 5G

Deploying cells in a 5G mobile communication environment has been a difficult optimization problem because many conflict factors, such as coverage ratio and interference, have to be taken into account at the same time. The hyper-dense deployment problem (HDDP) for the 5G environment has attracted the attention of researchers from different disciplines, because it provides a way to depict the deployment problem we have to confront in a 5G environment. In this paper, an effective search algorithm is presented for solving the HDDP. The proposed algorithm is based on a novel metaheuristic algorithm, called search economics for hyper-dense deployment problem (SE-HDDP); the main difference is in that it will divide the solution space into a set of subspaces and determine the investment of searches based on the expected value (i.e., potential) of each subspace. The simulation results show that the proposed algorithm is able to find a better solution than the other metaheuristic and rule-based algorithms compared in this paper.

Anonymous and expeditious mobile user authentication scheme for GLOMONET environments

SummaryThe Global Mobility Network (GLOMONET) is rapidly becoming important as well as a popular feature in today's high‐performance network. The legal mobile users enjoy life using the ubiquitous services via GLOMONET. However, because of the broadcast nature of the wireless channel, providing user authentication along with the privacy and anonymity of the users in GLOMONET is indeed a challenging task. In this article, we come up with a secure and expeditious mobile communication environment using symmetric key cryptosystem to ensure mobile users' anonymity and privacy against eavesdroppers and backward/forward secrecy of the session key. Our scheme can also protect numerous security threats, like man‐in‐the‐middle attack, known session key attack, lost smartcard attack, and forgery attack. Furthermore, we put forward a new technique named as “friendly foreign agent policy,” where many foreign agents can make different groups among themselves and perform important responsibilities to authenticate a legitimate mobile user without interfering his or her home agent even though the mobile user moves to a new location, covered by a new foreign agent (belongs to the same group). Security and performance analyses show that the proposed scheme is secure and more efficient as compared with other competitive schemes for GLOMONET environments.

Spatial Signature Modulation: A Novel Secure Modulation Approach for MIMO Wiretap Channel

Security in physical and application layers have been always thought of as a complementary paradigm. In this paper, we argue that potential cooperation between physical and application layers provides several advantages and unique features that are not available in each paradigm by itself. The problem of exchanging confidential messages between nodes, A and B, in the presenceof an active adversary, E, over an insecure MIMO channel is considered. We introduce a double layer spatial signature modulation (SSM) in which the transmitted information is conveyed into the spatial signature of the transmitting antenna array observed by the intended receiver. Meanwhile, any other eavesdropper does not share the same bearing angle of the legitimate receiver obtains infinitesimally small amount of information. Further, to establish a secure link, A and B are required to share a secret common information prior to communication while keeping E ignorant about it. To that end, we introduce a novel physical layer assisted secret key agreement (SKA) protocol that leverages the cooperation between physical and application layer security. Angle of Arrival (AoA) and Angle of Departure (AoD) are physical layer parameters that can be exploited not only for their well performance at low SNR, but also for their contextual meaning that provides security advantages. In the proposed SKA protocol, AoA is explored as a physical mean for message source authentication, meanwhile, AoD is used as a common source of randomness in a smart signal processing approach to generate secret key bits without any extra communication overhead. We show that E can be kept ignorant about the generated key bit stream conditioned on its physical location. This work introduces the notion of physical hardness to an adversary pursuing either active or passive strategy. After establishing a secret common information, we show that the continuous use of AoA as a mean for message source authenticity provides a considerable advantage against active adversary during the message exchange phase. Extending the proposed scheme to a mobile communication environment is also provided. Finally, quantitative analysis for the security gain due to the potential cooperation between physical and application layer security is developed..