Cellular Mobile Systems Research Articles

Survey on 5G Physical Layer Security Threats and Countermeasures.

With the expansion of wireless mobile networks into both the daily lives of individuals as well as into the widely developing market of connected devices, communication is an increasingly attractive target for attackers. As the complexity of mobile cellular systems grows and the respective countermeasures are implemented to secure data transmissions, the attacks have become increasingly sophisticated on the one hand, but at the same time the system complexity can open up expanded opportunities for security and privacy breaches. After an in-depth summary of possible entry points to attacks to mobile networks, this paper first briefly reviews the basic principles of the physical layer implementation of 4G/5G systems, then gives an overview of possible attacks from a physical layer perspective. It also provides an overview of the software frameworks and hardware tool-software defined radios currently in use for experimenting with 4G/5G mobile networks, and it discusses their basic capabilities. In the final part, the paper summarizes the currently most promising families of techniques to detect illegitimate base stations-the machine-learning-based, localization-based, and behavior-based methods.

Coverage Analysis and Proposed Cell Sizes to Enhance the Performance of the 5G Cellular System

The global demand for more digital data motivates the evolution of mobile communication systems from 2G and 3G to 4G and 5G to support high data rate applications. The International Mobile Telecommuication-2020 (IMT-2020) defined the minimum technical performance requirements and guidelines for evaluating the 5G mobile cellular system. The New Radio (NR) millimeter wave (mmWave) and massive Multiple Input Multiple Output (mMIMO) antenna systems are technologies used in the 5G cellular system. Therefore, this paper studies the performance of the mmWave system combined with the mMIMO antenna system using the IMT-2020 channel model in a dense urban microenvironment, considering different frequency bands and numbers of elements at the Base Station (BS) antenna array. The performance is evaluated through system-level simulation in terms of Signal power to Noise power Ratio (SNR), Spectral Efficiency (SE), and cell edge user SE. A cell size reduction technique is proposed to meet the target requirements set by IMT-2020. Simulation results showed that the sub. 6 GHz frequency bands achieve the target SE of IMT-2020, while in the mmWave frequency range, the target SE requirement can be achieved using a high number of antenna elements at the BS antenna for some frequency bands.

Energy Conservation for Mobile Cellular Systems through Site Optimization (Base Transceivers Station Optimization)

Mobile communication systems have cemented their position as a vital and practical tool for communication that supports productive corporate operations. The energy use of wireless access networks has grown to be a significant economic and environmental problem, the potential for utilizing the conserved energy was highlighted along with techniques that may boost energy efficiency in this paper's investigation of the energy consumption of base transceivers stations (BTS). Analysis of the data reveals that by optimizing 60 BTSs, the energy consumption decreases by 36.83% with 127.4MWh of monthly reserve. This is equivalent to powering 35 additional BTSs with a demand of 3.64224MWh or 69 homes for a daily power supply of 10 hours with a demand of 1.8452MWh and 440 homes with a total demand of 289.8KWh.

Optimum Base Station Antenna Tilt Angle for Inter-Cell Interference Limited Mobile Cellular System

This paper investigates the effect of base station (BS) antenna tilt angle on the performance of LTE-Advanced physical layer downlink channel in Inter-Cell Interference (ICI) limited scenario for five cell ranges, two carrier frequencies, and two BS antenna heights. The cellular system is deployed following the 3GPP hexagonal grid with a frequency reuse factor of one and three sectors per site. An urban based 3D ray-tracing tool is used to model the wireless channel for many BS and user equipment (UE) links. System performance is evaluated in terms of Signal power to Interference plus Noise power Ratio (SINR), received signal power, received interference power, achievable throughput (THR), Average Spectrum Efficiency (ASE) and UEs outage probability. The objective is to find the BS antenna tilt angle that provides the maximum ASE, minimum UEs outage probability, or optimum ASE and UE outage probability. The obtained simulation results unveil that the maximum ASE occurs at a tilt angle where the mean of the SINR is maximum and the mean of rms delay spread is minimum, while the minimum UEs outage occurs at a tilt angle where the received signal power is maximum. This is an important finding to facilitate the planning and the deployment of cellular system in the presence of ICI. Moreover it is found that the optimum tilt angles decrease as the cell range increase and BS antenna height decrease. The results also show that these optimum tilt angles are independent of the carrier frequency.

Energy Conservation for Mobile Cellular Systems Through Site Optimization: Base Transceivers Station Optimization

Energy Conservation for Mobile Cellular Systems Through Site Optimization: Base Transceivers Station Optimization

Intelligent Jammer on Mobile Network LTE Technology: A Study Case in Bucharest

The purpose of this study was to develop a laboratory model that enables the monitoring of communications carried out through mobile phones and their blocking in cases where it is prohibited. The main goal was to realise an intelligent jammer that blocks only illicit communications. The jammer was built with a software-defined radio (SDR) that can be found on the market and is accessible from a financial point of view. This study consisted of an analysis of the behaviour of mobile phones and mobile networks using the long-term evolution (LTE) of UMTS technologies so that the jamming technique can disrupt the communication of the cellular mobile system by using the software-defined radio and Python ecosystem. Because the 5G standalone (5G SA) is not yet implemented in Romania, we could not start developing a laboratory model for jamming this technology. When 5G SA is implemented, we will adapt this intelligent jamming solution to the new technology.

Frequency allocation algorithm

Wireless communication technology's quick advancement has facilitated the ongoing formation of numerous new communication business scenarios and the thorough connectivity of man-machine-object-space. The conflict between few channel resources and high demand is becoming more and more obvious, which adds to the stress on the entire network. In order to enhance communication quality with constrained frequency resources, more optimal channel allocation techniques are urgently required. This paper discusses the increasing demand for frequency resources due to the exponential growth of data traffic, which has necessitated more efficient channel allocation methods to optimize communication quality with limited frequency resources. The evolution of mobile wireless cellular communication systems from the first generation to the current fifth generation, and the imminent emergence of the sixth generation, are also discussed. The paper highlights the importance of ultra-dense networks and device-to-device communication in meeting the capacity and coverage requirements of 5G networks. The advantages and disadvantages of different frequency reuse methods, specifically Fractional Frequency Reuse (FFR) and water injection algorithm, are analyzed. The paper summarizes these methods' principles and application effects in specific situations, emphasizing the need for appropriate frequency reuse methods to achieve optimal channel allocation and communication quality.

RF Health Safety Limits and Recommendations [Health Matters

The rapid proliferation of cellular mobile telecommunication devices and systems is raising public health concerns about the biological effects and safety of RF radiation exposure. There is also concern about the efficacy of promulgated health safety limits, rules, and recommendations for the RF radiation used by these devices and systems. This article reviews and discusses the U.S. Federal Communications Commission (FCC) notices and rules, International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines, and International Committee on Electromagnetic Safety (ICES) standard for safety levels with respect to human exposure to electric, magnetic, and electromagnetic fields (EMFs). The recently revised RF exposure limits are adjusted only for heating with RF radiation. These limits are largely intended to restrict short-term heating by RF radiation that raises tissue temperatures. They are narrow in scope and are not applicable to long-term exposure at low levels. This review discusses the assumptions underlying the standards and the outdated exposure metrics employed, and concludes that the revised guidelines do not adequately protect children, workers, or the public from exposure to RF radiation or people with sensitivity to electromagnetic radiation from wireless devices and systems. Furthermore, the review discusses important animal data that the standards do not appear to take into account. Moreover, for millimeter-wave radiation from 5G mobile communications, there are no adequate human health effects studies in the published literature. The conclusions by scientific organizations, such as the International Agency for Research on Cancer (IARC), that diverge from these standards are also discussed. The review concludes that many of the recommended limits are debatable and require more scientific justification from the standpoint of safety and public health protection.

INVESTIGATING THE PATH LOSS OF CELLULAR MOBILE NETWORK IN SUBURBAN AREAS OF BENIN METROPOLIS OF NIGERIA AT 910MHZ

This paper focuses on investigating path loss of mobile cellular network in suburban areas of Benin metropolis at a propagation frequency of 910MHz. The network Cell Info Lite application installed in GIONEE M5 CDMA was used to measure the received signal strength of the transmitted signal. The relative parameters were obtained from 100meters from the Glo base station from August, 2021 to October, 2021 within an average temperature of 270C. The results showed that Hata models are extensively used for the analysis of path loss evident in mobile cellular networks, GSM and CDMA system as depicted by the terrain of sub-urban areas of Benin City Metropolis. It was observed that the more the mobile stations move away from the base station, the higher the signal loss. This paper therefore guides cellular network service provider on accurate method of designing, deploying, and managing network to enhance good network coverage.

A Proposed Analytical Inter-Cell Interference Model for Mobile Cellular Systems with Isotropic Antenna

4G and beyond cellular systems intend to use a frequency reuse factor of one with three sectors per BS site. This configuration leads to an increase in inter-cell interference (ICI). Thus, ICI modeling is very necessary to design and analyze any cellular system. The impact of ICI is modeled analytically in this paper. The effect of six interfering BS sites surrounding the serving BS is examined. The ICI is first mathematically modeled as a function of BS-UE distance for several environments based on pathloss exponent and then validated using an explicit simulation model. Secondly, the results obtained from the proposed model and the explicit simulation model are compared. The comparisons showed good agreement between the results of the proposed model and the simulation model. The mathematical model is convenient to the standardized ITU-R model and has the flexibility to apply any antenna patterns that is compatible with these international models. Furthermore, this model enables ICI estimation by deploying the serving BS cell only without the need to deploy the surrounding nine interfering cell. This has positive impact on reducing the time required for system level simulation.

Impact of Inter Cell Interference on the Performance of Homogenous Cellular Systems

Deployment of cellular system with frequency reuse of one is critical to support increased data traffic and high data rate applications in 4G and beyond radio interface technologies. Such deployment leads to substantial increase in Inter-Cell Interference (ICI). Therefore, this paper investigates and evaluates the capacity performance of mobile cellular system with a frequency reuse of one and three-sector per Base Station (BS). The communication channel between the BSs and user equipment links is modeled using ITU-R channel model. The study considers different carrier frequencies and different cell ranges. The system performance is assessed in terms of Signal to Noise Ratio (SNR), Signal to Interference plus Noise Ratio (SINR) and ergodic capacity. The SNR and ergodic capacity improve significantly as the cell range and carrier frequency decreases for ICI free scenario. However, for ICI scenario, there are slight variation in the performance when changing the cell range and the carrier frequency. The study recommends a cell size of 800 m.

Steady State Analysis of Base Station Buffer Occupancy in a Cellular Mobile System

The 3rd generation partnership project (3GPP) standards organizations makes great efforts in order to reduce the latency of 5G mobile networks to the least possible extent. Recently, these networks are associated with big buffers to maximize the network utilization and minimize the wasted wireless resources. However, in existence of the TCP congestions, having bottlenecks are still expected on radio access networks (RANs) data paths. Consequently, this influences the network performance and reduces its quality of services (QoSs). Apparently, studying and improving the behavior of buffers deployed at 5G mobile networks devices can contribute to solving these problems (at least by reducing the queuing time at these buffers). In this paper, we study the buffer behavior of base stations in a 5G mobile network at steady state. We consider a cellular mobile network consisting of finite number of users (stations, terminals, and mobiles). At any time-slot, a station may be using the channel (busy) or not using the channel (idle). Since system analysis of cellular mobile networks in general form is rather complex, solutions are always obtained in closed forms or by numerical techniques. A two-dimensional traffic system for cellular mobile networks is presented, and the main performance evaluations are derived. Moreover, different moments of the base station buffer occupancy are calculated. The study reveals that there is a correlation between the state of the mobile stations (busy or idle) and the expected buffers occupancy of the base station. In addition, the results discussions demonstrate some important factors and parameters that affect the base station buffers and the overall network performance. These factors can be further worked on and controlled to obtain the least possible latency in next generation mobile networks.

K-means Clustering, Unsupervised Classification, K-NN, Euclidean Distance, Genetic Algorithm

In recent days, the need to provide reliable data transmission over Internet traffics or cellular mobile systems becomes very important. Transmission Control Protocol (TCP) represents the prevailing protocol that provide reliability to data transferring in all end-to-end data stream services on the Internet and many of new networks. TCP congestion control has become the key factor manipulating the behavior and performance of the networks. TCP sender can regulates the size of the congestion window (CWND) using the congestion control mechanism and TCP dynamically adjust the window size depending on the packets acknowledgment (ACK) or by indicates the packets losses when occur. TCP congestion control includes two main phases, slow-start and congestion avoidance and these two phases even work separately, but the combination of them controls CWND and the packet injection to the network pipe. Congestion avoidance and slow-start are liberated mechanisms and using unlike objectives, but if the congestion happens, they are executed together. This article provides an efficient and reliable congestion avoidance mechanism to enhancing the TCP performance in large-bandwidth low-latency networks. The proposed mechanism also includes a facility to send multiple flows over same connection with a novel technique to estimate the number of available flows dynamically, where the all experiments to approving the proposed techniques are performed over the network simulation NS-2.

The key moment in the genesis of mobile cellular systems. Control of radio links in universal mobile cellular systems

The most crucial moment in the genesis of mobile cellular systems is the implementation of a universal telecommunications system, as one of its most important aspects is to integrate existing second-generation cellular standards into a single platform. Universal mobile systems are based on several different standards, one of which is WCDMA. It is compatible with the widespread GSM technology and uses a bandwidth between 5 MHz and 10 MHz, thus creating a stable platform for deploying applications using wide bandwidth. The purpose of this article is to present the main emphasis in the control of radio communications in universal mobile cellular systems. To systematize the protocols used in the layers related to radio control and to summarize their basic functions. Control processes such as radio interface measurements, handover, borrowing, reconfiguring, and releasing radio resources needed by one radio link and others are affected.

Research of femtocell technologies for mobile cellular networks

The purpose of writing this article is to present and study femtocellular technologies for mobile cellular networks. With the introduction of the fourth 4G-LTE and the fifth 5G generation of mobile cellular systems, the term femto cell began to be strongly mentioned. Femto cells are very small cells that provide mobile service users with a home base station to connect to the telecommunications operator's network. The femtocell technologies are mainly looking for ever higher data rates indoors, which most often leads to the implementation of UMTS / HSPA modules in the femtocell access point, as well as LTE and 5G.

Recency effect and self-regulating design of mobile cellular systems in the context of interlaced generations: network bandwidth, power efficiency, and connection reliability

The mobile cellular system is undergoing a generation-interlaced evolution from 2G/3G/4G to 5G, with various signals and protocols coexisting for a long period. A crucial but challenging problem that emerges is how to ensure high performance (fast transmission), high energy efficiency (low power consumption), and high reliability (stable connection) for the services in a large, heterogeneous, and highly dynamic cellular environment. This problem simultaneously involves mobile phone manufacturers, network service providers, and OS/application developers. In this paper, we comprehensively review the representative related works in recent years, and learn that a series of performance anomalies in cellular systems is in fact attributed to the “recency effect" at the core mechanisms. Upon selecting which mobile network to use, there exist generation biases and unconscious performance-first tendencies affected by public opinions and commercial promotions. The biases and tendencies lead to knock-on effects like the “loss-making migration" towards 5G, the “saturated hunger" of network capacity, and the “ping-pong jumping" among base station connections. To overcome the above shortcomings, we propose self-regulating techniques based on 4G/5G dual-connectivity and Time-Inhomogenous Markov Process, which reduce the failure rate of 5G devices by 40% and the average failure duration of all devices by 36%. We also discuss other insights and innovations based on large-scale industrial practice.

Millimeter-Wave Mobile Sensing and Environment Mapping: Models, Algorithms and Validation

Integrating efficient connectivity, positioning and sensing functionalities into 5G New Radio (NR) and beyond mobile cellular systems is one timely research paradigm, especially at mm-wave and sub-THz bands. In this article, we address the radio-based sensing and environment mapping prospects with specific emphasis on the user equipment (UE) side. We first describe an efficient <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula>-regularized least-squares (LS) approach to obtain sparse range&#x2013;angle charts at individual measurement or sensing locations. For the subsequent environment mapping, we then introduce a novel state model for mapping diffuse and specular scattering, which allows efficient tracking of individual scatterers over time using interacting multiple model (IMM) extended Kalman filter and smoother. Also the related measurement selection and data association problems are addressed. We provide extensive numerical indoor mapping results at the 28 GHz band deploying OFDM-based 5G NR uplink waveform with 400 MHz channel bandwidth, covering both accurate ray-tracing based as well as actual RF measurement results. The results illustrate the superiority of the dynamic tracking-based solutions, compared to static reference methods, while overall demonstrate the excellent prospects of radio-based mobile environment sensing and mapping in future mm-wave networks.

Performance Comparison for Single-User and Multi-User Network MIMO Cellular Systems with Power Management

Cellular mobile systems aim at aggressive spectrum reuse to achieve high spectral efficiency. Unfortunately, this leads to unacceptable interference near cell borders. To control this, network multi-input multiple-output (MIMO) can be adopted to improve coverage and cell-edge throughput through multi-cell cooperation. With network MIMO, multiple geographically separated base stations (BSs) cooperatively serve their cell-edge users (CEUs) using their antennas, acting together as a network of distributed antenna array. It can be single-user (SU) or multi-user (MU) network MIMO by coordinating channel allocation in adjacent cells. In this paper, we make a capacity comparison of SU- and MU-network MIMO. In network MIMO, a collaborative BS simultaneously serves its own cell-center users (CCUs) and CEUs, and the CEUs of other partner BSs under a power constraint. As a result, power management among three types of users (intra-cell CCUs/CEUs, inter-cell CEUs) becomes necessary. Accordingly, we propose power management methods to help raise the signal strength of inter-cell CEUs and in the meantime gratify the performance of intra-cell users. Simulation results show that MU-network MIMO with superposition coding offers much better CEU capacity than SU-network MIMO. As for the CCU capacity, MU-network MIMO is generally better than SU-network MIMO.

Groups of mobile cellular service stations for operational radio communication tasks in remote areas

The authors of the article consider solutions needed to organize mobile cellular communication systems in remote areas. Modern mobile stations do not have the capability to overcome marshy areas, steppe, heavily rugged reliefs of the desert, water barriers and forests. Moreover, the coverage area from one base station is not highly localized (radio coverage area is not significant). Furthermore, modern mobile communication facilities have poor autonomy. The article proposes measures for an operational organization of cellular communications in large remote areas with a coverage radius of a medium-sized city. Article also considers the issues posed by a temporary organization of communication service in large sections near important locations (pipelines, riverbeds, transport and railway lines). The need for such an operational usage of mobile communication systems is most associated with geological exploration and scientific research in large remote areas and large areas with a damaged communication system due to natural emergencies or military operations.

Analyzing the Effect of Radiation on Human beings of Electromagnetic waves from BTS and MS in Kushtia, Bangladesh

Based on Base Transceiver Station (BTS) and Mobile Station (MS) radiation, the residence of Kushtia district in Bangladesh is usually concerned with the potential health effects. Inhabitants, living in this part of Bangladesh are using communication, internet browsing, and other related uses with the help of mobile cellular communication system. The subscriber needed improving radio coverage, excellent communication networks, and quicker speed for internet browsing with the recent developments in mobile cellular communication technologies. To meet this demand, service providers of mobile cellular companies set up several BTS, which emit harmful radiation that has extremely detrimental impact on the human body. Through this paper, the effects of electromagnetic radiation of MS as well as BTS on the human body have been analyzed and Electromagnetic Field (EMF) radiation levels of MSs along with BTSs located in this region have been measured. These measurements have been compared with the measured value provided by the World Health Organization (WHO) and International Commission of Non-Ionizing Radiation Protection (ICNIRP). Finally, a cross-sectional analysis was carried out to evaluate the understanding and self-reported health risks of Electromagnetic waves (EMW) radiation emittedfrom the MS as well as BTS among the inhabitants of this region who are living near and a little away from BTS.