User Density Research Articles

Harnessing Intelligent RIS for Optimized Capacity and Latency in 6G Cooperative NOMA Systems

This article examines the performance of cooperative NOMA systems in a massive MIMO configuration inside the sixth-generation (6G) network, including scenarios with and without reconfigurable intelligent surfaces (RIS). The emphasis is on comprehending the effects of implementing static, dynamic, and intelligent RIS on the capacity of the cooperative NOMA system with differing user quantities. The study examines how different user loads and RIS densities affect average latency and effective area spectral efficiency (EASE). Integration of a proposal system in a novel way with water-filling in the multi-user channel logarithm to enhance capacity, average latency, and EASE for diverse user densities. The results show that RIS significantly improves capacity, average latency, and EASE, especially with intelligent RIS. All scenarios, in conjunction with the suggested algorithm, markedly improve network performance, particularly under conditions of increased user demand. Additionally, it enhances the system's capability and spectrum efficiency, especially when deployment numbers rise.

Relational Analysis of User Density, Number of Train Services and Population around Rail Stations on Local Railways in Japan

Relational Analysis of User Density, Number of Train Services and Population around Rail Stations on Local Railways in Japan

3-D Placement of Aerial Base Stations to Support Terrestrial Network Based on Adaptive Particle Swarm Optimization

Problem statement. With the increasing load on terrestrial communication networks, it is necessary to implement new solutions to ensure stable and high-quality user service. One of the promising approaches is the use of aerial base stations (ABS), which can be rapidly deployed in areas with high user density or during emergency situations. This paper addresses the problem of three-dimensional deployment of ABS to support terrestrial communication networks, where the number of users exceeds the capacity of the current ground-based system. The main goal of this work is to determine the minimum number of ABS and their optimal placement while meeting user service requirements. However, this is an NP-hard problem (nondeterministic polynomial-time hardness), so to solve it, we propose using Adaptive Particle Swarm Optimization. Scientific novelty: the proposed approach consists in developing a method for optimizing three-dimensional ABS placement using an adaptive particle swarm algorithm aimed at minimizing the number of ABS while maintaining high quality of service to users. Unlike classical PSO, the proposed algorithm allows connecting more users to ABS due to more efficient resource allocation and selection of ABS location. Simulation results show that the proposed algorithm ensures high coverage performance in environments with various user distributions. Theoretical / practical significance: In practice, the results can be used in planning and deploying ABS in congestion or emergency situations to ensure sustainable coverage.

Use of Low-Cost Technologies for Monitoring User Density on Beaches: A Case Study of Guarita Beach, Southern Brazil

Use of Low-Cost Technologies for Monitoring User Density on Beaches: A Case Study of Guarita Beach, Southern Brazil

Summer outdoor thermal risk area mapping on a university campus in Auckland, New Zealand

Outdoor thermal risks in urban areas are increasingly critical due to climate change and urbanization. This study identifies high-risk areas at Auckland University of Technology, New Zealand, using a multi-layered approach integrating hazard, exposure, and vulnerability. Locations with Physiologically Equivalent Temperature (PET) exceeding 23°C were analyzed alongside user density and survey-based vulnerability assessments, pinpointing two high-risk zones. Future projections for 2050 and 2080 (RCP 4.5 and RCP 8.5 scenarios) indicate rising PET levels, amplifying thermal discomfort. Mitigation strategies, including green walls and tree planting, demonstrated PET reductions of 2°C and 3°C, respectively, under current conditions. These findings underscore the critical role of greenery in enhancing outdoor thermal comfort and resilience. The study’s replicable methodology offers urban planners a practical framework for addressing thermal risks and adapting outdoor spaces to climate change impacts, fostering urban livability.

Optimizing resource allocation for enhanced urban connectivity in LEO-UAV-RIS networks

Optimizing resource allocation for enhanced urban connectivity in LEO-UAV-RIS networks

Development model of a high-performance multiple input multiple output microstrip antenna based on a planar series array with 8×2 elements for 5G communication systems

MIMO (Multiple Input Multiple Output) makes a major contribution to 5G communication systems by increasing network capacity and spectrum efficiency. In 5G, MIMO enables the use of multiple antennas at base stations and user devices, allowing simultaneous sending and receiving of data over multiple paths. This significantly increases data throughput and connection reliability, especially in environments with high user density. In addition, MIMO technology supports the implementation of beamforming, which focuses signals on a specific direction, reduces interference, and improves signal coverage and quality, making it one of the keys to achieving faster and more responsive 5G performance. Therefore, antennas with wide bandwidth, high gain and MIMO performance are crucial for supporting 5G communication systems. This paper proposes a high-performance MIMO microstrip antenna based on a series planar array with 8×2 elements operating at a resonant frequency of 3.5 GHz for 5G communication systems. A spiral stub and a feed inset are proposed to control the reflection coefficient and bandwidth of the antenna while the series planar array is proposed to increase the gain. To support the MIMO communication system, the proposed antenna is separated into two different ports with a certain distance. From the measurement results, the proposed antenna has high performance indicated by a wide bandwidth of 680 MHz (3–3.68 GHz) and a high gain of 17.8 dB at a resonant frequency of 3.5 GHz. In addition, the proposed antenna has high mutual coupling and diversity indicated by ECC and DG of 0.001 and 9.99 dB, respectively. This work provides a solution to design a high-performance microstrip antenna and can be implemented as a receiving antenna for 5G communication systems

The concept of effective coverage radius use of the unlicensed high-frequency range in the operation of the 5G network

Economic expediency encourages mobile operators to deploy 5G networks in places with a high concentration of speed-demanding subscribers. In such conditions, sharp fluctuations in the volume of traffic with regulated requirements for the quality of service are inevitable. Note that 5G operates in the millimeter range. Accordingly, the quality of traffic service is affected both by the number of subscribers simultaneously initiating requests from one sector of coverage, and by the appearance of obstacles opaque to radio radiation in the space between the subscriber device and the base station. Effective smoothing of 5G traffic fluctuations, taking into account these disturbing factors, is an urgent task. The goal of this research is to evaluate the service quality parameters in a target area characterized by a specific user density. It takes into account that if the declared QoS requirements for connection speed for users in a network segment deployed within the licensed frequency range for 5G are not met, they can utilize a network segment deployed in the unlicensed high-frequency range for 5G under conditions of free competition. The metric being studied is the probability of session loss in the licensed network segment and the achievable transmission speed in the unlicensed network segment. Based on this, a method for assessing the density of base station deployment in the unlicensed network segment necessary to support the specified user density in the licensed network segment with defined QoS guarantees in terms of bandwidth is formalized. The experiment results showed that the probability of losing sessions with regulated requirements for the quality of service in both network segments, in addition to the base station placement density and subscriber devices, is significantly affected by the minimum data transfer rate, the intensity of obstacles, and the value of the Contention Window.

Digital Dividends: Exploring The Impact Of Telecommunication Infrastructure On Economic Growth In India

This paper examines the effect telecommunications infrastructure has on the growth of the Indian economy, emphasising the role that telecommunication usage and tools play on the GDP per capita and other economic parameters. It accesses information from different organisations, including the Telecom Regulatory Authority of India and UDISE+, to study the links between wireless and wireline users, user density, and school digital access and their impact on economic indicators. With advanced econometrics models, i.e. OLS regression, correlation analysis, random forests, step-wise regression, granger analysis, adfuller, and others, predictable solid relationships and directional relationships are proved to exist between the telecommunications background and GDP growth variable. The study results indicate that in India, there is a strong correlation between internet access in schools and wireless internet users. Moreover, it proposes policies to catalyse economic growth and digital adoption in India. It is a resource that policymakers can leverage to make the right decisions in harnessing the power of ICT for economic development

Corneal endothelial density and morphology in long-term soft contact lens users in Japan: a retrospective cross-sectional study of 17,732 eyes

Purpose There is a lack of long-term and large-scale studies on the adverse effects of soft contact lenses (SCLs) on the corneal endothelia of Asian populations. Here, we aimed to examine the effects of long-term SCL use on corneal endothelial density and morphology. Materials and Methods This retrospective study involved consecutive patients at the Miyata Eye Hospital (Miyazaki, Japan), who had used SCLs for more than 1 year. Patients with ophthalmological disorders without refractive errors were excluded. The period of SCL use, SCL type, corneal endothelial cell density (ECD), appearance rate of hexagonal cells (HEX), and coefficient of variation of cells (CV) were analyzed. Results In total, 17,732 eyes of 8866 patients were included in the analysis (age, 26.0 ± 8.8 years). The mean period of SCL use was 6.3 ± 5.4 years. Multivariate regression analysis revealed that ECD and HEX were significantly negatively correlated with the period of SCL use, age, and sex (p < 0.001 for all). The CV was significantly positively correlated with the period of use (p < 0.001), sex (p = 0.002), and age (p < 0.001). Conclusions Corneal ECD, HEX, and CV were significantly associated with the period of SCL use in long-term users. It is essential to regularly check the corneal endothelium in patients with a history of long-term SCL use.

Improving Network Service Quality in parts of Sampang City: QoS Evaluation and User Perception of QoE

In an era of rapid urbanization, the quality of network services in urban environments is becoming increasingly important. This article explores efforts to improve network service quality in several sampang cities through an evaluation of Quality of Service (QoS) and user perceptions of Quality of Experience (QoE). The research is based on a survey conducted at various locations in sampang city to collect data on the reliability, speed, and availability of network services. The survey involved a diverse sample of users, covering a wide range of ages, professions, and levels of technology usage. In addition, we also analyzed users' perceptions of service quality based on their experiences of using the network in an urban environment. The results highlighted several key challenges in improving QoS, such as user density, signal interference, and network infrastructure limitations. However, we also found that strategies such as the use of advanced network technologies, such as 5G and beamforming, as well as traffic prioritization based on application type, can help to significantly improve QoS. In addition, we found a strong positive correlation between improved QoS and improved QoE, suggesting that improved quality of service has a direct impact on improving user experience. These findings provide valuable insights for network operators and policy makers in their efforts to improve network services in dense urban environments. The research also recommends further investment in network technologies and the development of policies that support more effective management of network traffic to ensure optimal quality of service.

Implementation of 802.11ax and cell-free massive MIMO scenario for 6G wireless network analysis extending OMNeT++ simulator

In an era where ubiquitous connectivity and escalating data demands are altering the landscape of wireless communications, our paper proposes a pioneering enhancement for the OMNeT++ simulator to support the advanced features of IEEE 802.11ax high efficiency (HE) alongside cell-free massive multiple-input multiple-output (MIMO) systems. Traditional wireless networks face daunting challenges in sustaining elevated quality of service (QoS), primarily due to fluctuating user densities and signal quality. Cell-free massive MIMO serves as a compelling answer to this predicament by decentralizing the cellular architecture. It eradicates conventional cell boundaries, furnishing uniform QoS regardless of user locations. However, these advancements come at the expense of complex backhaul networks and articulated joint signal processing. The 802.11ax standard, touted for its robustness and efficiency, remains underexplored in this new paradigm. Our research not only dissects the architectural elements and constraints of both 802.11ax and cell-free massive MIMO but also elaborates on the adaptations required to extend OMNeT++ functionalities for these technologies. By doing so, we bridge a crucial gap, enabling the simulator to provide a more precise, detailed, and scalable evaluation of emerging 6G scenarios and directional communications also taking into account the impact of the most known routing protocols such as dynamic source routing (DSR), ad hoc on-demand distance vector routing (AODV), optimized link state routing (OLSR), and dynamic mobile ad hoc network on-demand (DYMO) that were selected for this comparative study. The proposed extensions promise to revolutionize network simulations and lay the foundation for in-depth analyses of wireless systems in complex and dynamic environments. Through extensive simulations, our study demonstrates that cell-free massive MIMO configurations significantly improve network throughput in high-density mobile ad hoc network (MANET) environments, with results indicating an average throughput gain of up to 30% compared with non-cell-free configurations. This improvement highlights the efficacy of cell-free massive MIMO to take advantage of the spatial and frequency multiplexing capabilities inherent in the 802.11ax standard, making it a promising solution for future wireless systems in densely populated areas.

What affected the vitality of high-speed rail station areas? A case study of Chengdu-Chongqing urban agglomeration, China

With the rapid expansion of high-speed rail (HSR), the HSR station areas are often the key development areas of the cities and the gateways to display the cities’ image. However, the problem of lack of vitality in these areas has emerged. Limited studies have quantified the vitality of HSR station areas and examined the factors influencing it. The purpose of this study is to assess the impact of various factors on the vitality of HSR station areas. To accomplish this objective, we propose a method for measuring the vitality of HSR station areas using Baidu’s real-time user density data. We demonstrate the method through the case study of 91 HSR station areas in the Chengdu-Chongqing urban agglomeration in China. We construct structural equation models using a Bayesian approach to test the effects of intercity accessibility, intracity accessibility, surrounding area density, and local socio-economic development on the vitality of HSR station areas. The results show that (1) Intracity accessibility, surrounding area density, and local socioeconomic development have significant positive effects on the vitality density of HSR station areas. Intercity accessibility has a negative effect on the vitality density of HSR station areas. (2) Surrounding area density positively influences the stability of weekday and weekend vitality in HSR station areas. Local socio-economic development negatively impacts the stability of weekend vitality in HSR station areas. (3) High-vitality HSR station areas are mostly located in Chengdu and Chongqing, both megacities. Station areas with low vitality are primarily located in small cities. This study’s findings can be used to guide the planning and decision-making of HSR station areas aimed at enhancing their vitality.

User-Centric Internet of Things and Controlled Service Scheduling Scheme for a Software-Defined Network

Mobile users can access vital real-time services through wireless paradigms like software-defined network (SDN) topologies and the Internet of Things. Point-of-contact-based infrastructures and dynamic user densities increase resource access and service-sharing concurrency. Thus, controlling power consumption and network and device congestion becomes a major issue for SDN-based IoT applications. This paper uses the Controlled Service Scheduling Scheme (CS3) to address the challenge of simultaneous scheduling and power allocation. The suggested approach uses deep recurrent learning and probabilistic balancing for power allocation and service distribution during user-centric concurrent sharing intervals. The SDN control plane decides how much power to use for service delivery while forecasting user service demands directs the scheduling interval allocation. Power management is under the control plane of the SDN, whereas service distribution is under the data plane. Power-to-service requirements are evaluated probabilistically, and updates for both aircraft are obtained via the deep learning model. This allocation serves as the basis for training the learning model to alleviate power deficits across succeeding intervals. The simulation experiments are modeled using the Contiki Cooja simulator, where 200 mobile users are placed. The proposed plan delivers a 14.9% high-service distribution for various users, 18.29% less delay, 13.34% less failure, 5.54% less downtime, and 18.68% less power consumption.

Integrating Multi-Access Edge Computing (MEC) into Open 5G Core

Multi-Access Edge Computing (MEC) represents the central concept that enables the creation of new applications and services that bring the benefits of edge computing to networks and users. By implementing applications and services at the edge, close to users and their devices, it becomes possible to take advantage of extremely low latency, substantial bandwidth, and optimized resource usage. However, enabling this approach requires careful integration between the MEC framework and the open 5G core. This work is dedicated to designing a new service that extends the functionality of the Multi-Access Traffic Steering (MTS) API, acting as a strategic bridge between the realms of MEC and the 5G core. To accomplish this objective, we utilize free5GC (open-source project for 5G core) as our 5G core, deployed on the Kubernetes cluster. The proposed service is validated using this framework, involving scenarios of high user density. To conclude whether the discussed solution is valid, KPIs of 5G MEC applications described in the scientific community were sought to use as a comparison parameter. The results indicate that the service effectively addresses the described issues while demonstrating its feasibility in various use cases such as e-Health, Paramedic Support, Smart Home, and Smart Farms.

The Interplay of Spectral Efficiency, User Density, and Energy in Grant-Based Access Protocols

We employ grant-based access with retransmissions for multiple users with small payloads, particularly at low spectral efficiency (SE). The radio resources are allocated via non-orthogonal multiple access (NOMA) in the time into T slots and frequency dimensions, with a measure of non-orthogonality η. Retransmissions are stored in a receiver buffer with a finite size C buf and combined via Hybrid Automatic Repeat reQuest (HARQ), using Chase Combining (CC) and Incremental Redundancy (IR). We determine the best scaling for the SE (bits/rdof) and for the user density J/n, for a given number of users J and a blocklength n, versus signal-tonoise ratio (SNR, ρ) per bit, i.e., the ratio E b /N 0 , for the sum-rate optimal regime and when the interference is treated as noise (TIN), using a finite blocklength analysis. Contrasting the classical scheme (no retransmissions) with CC-NOMA, CC-OMA, and IR-OMA strategies in TIN and sum-rate optimal cases, the numerical results on the SE demonstrate that CC-NOMA outperforms, almost in all regimes, the other approaches. For high C buf and small η, IR-OMA could surpass CC-NOMA. At low E b /N 0 , the SE of CC-OMA with TIN, as it exploits CC and offers lower interference, can approach the trend of CC-NOMA and outperform the other TIN-based methods. In the sum-rate optimal regime, the scalings of J/n versus E b /N 0 deteriorate with T , yet from the most degraded to the least, the ordering of the schemes is as (i) classical, (ii) CC-OMA, (iii) IR-OMA, and (iv) CC-NOMA, demonstrating the robustness of CC-NOMA. Contrasting TIN models at low ρ, the scalings of J/n for CC-based models improve the best, whereas, at high ρ, the scaling of CC-NOMA is poor due to higher interference, and CC-OMA becomes prominent due to combining retransmissions and its reduced interference. The scaling results are applicable over a range of η, T , C buf , and J, at low received SNR. The proposed analytical framework provides insights into resource allocation in grant-based access and specific 5G use cases for massive ultra-reliable low-latency communications (URLLC) uplink access.

Multinomial logit regression adoption: Identifying user characteristics of e-wallets in Can Tho City, Vietnam

This research adopted Multinomial Logit Regression to investigate factors that influence users’ choice of e-wallets and how these elements affect the probability of current e-wallet usage, suggesting that each service is preferred by different user groups based on demographic and behavioural traits. This paper employed a quantitative approach using a face-to-face survey of 140 respondents using e-wallets in Can Tho City, Vietnam. This study has identified the user characteristics of the top three e-wallet services in Can Tho City, Vietnam, suggesting that each service has unique features that attract different user groups. People with lower incomes, who frequently use e-wallets and engage in smaller transactions, prefer the MoMo e-wallet, which has emerged as the market leader. On the other hand, ZaloPay attracted men with higher incomes, while older individuals with higher spending patterns who used Agribank or MBBank preferred Other e-wallets. E-wallet service providers could identify their target audience through the research findings and then work on developing both existing and new features that align with the needs of those potential users, all aimed at boosting loyalty and expanding user density. However, a more extensive and diverse sample is required to provide a more reliable and comprehensive understanding.

Assessment and mapping of noise pollution in recreation spaces using geostatistic method after COVID-19 lockdown in Turkey

Increased use of recreational areas after the lifting of COVID-19 pandemic restrictions has led to increased noise levels. This study aims to determine the level of noise pollution experienced in recreational areas with the increasing domestic and international tourism activities after the lifting of pandemic lockdowns, to produce spatial distribution maps of noise pollution, and to develop strategic planning suggestions for reducing noise pollution in line with the results obtained. Antalya-Konyaaltı Beach Recreation Area, the most important international tourism destination of Turkey, is determined as the study area. To determine the existing noise pollution, 31 measurement points were marked at 100 m intervals within the study area. Noise measurements were taken during the daytime (07:00–19:00), evening (19:00–23:00), and nighttime (23:00–07:00) on weekdays (Monday, Wednesday, Friday) and weekends (Sunday) over 2 months in the summer when the lockdown was lifted. In addition, the sound level at each measurement point was recorded for 15 min, while the number of vehicles passing through the area during the same period was determined. The database created as a result of measurements and observations was analyzed using statistical and geostatistical methods. After the analysis of the data, it was found that the co-kriging-stable model showed superior performance in noise mapping. Additionally, it was revealed that there is a high correlation between traffic density and noise intensity, with the highest equivalent noise level (Leq) on weekdays and weekend evenings due to traffic and user density. In conclusion, regions exposed to intense noise pollution were identified and strategic planning recommendations were developed to prevent/reduce noise sources in these identified regions.

Assessment of airborne bacteria in the indoor of public-use facilities concentrated on influencing factors and opportunistic pathogenic bacteria

For public-use facilities in urban centers with high occupancy, it is imperative to effectively manage opportunistic pathogenic bacteria due to the diverse range of users, including the immunocompromised population, such as the elderly, children. Therefore, we investigated the concentration of airborne bacteria at several public-use facilities in urban centers in South Korea. The level of total airborne bacteria in the facilities was positively correlated with user density and CO2 levels. Notably, subway compartments demonstrated particularly high levels of airborne bacteria. Subway compartments and daycare centers contained opportunistic pathogenic bacteria associated with antibiotic resistance. The relative abundance of genera associated with these species showed minor differences by season and facility; the genera Klebsiella and Staphylococcus showed high relative abundance in subway compartments and daycare centers, respectively. Based on our findings, we recommend enhancing management strategies targeting opportunistic pathogenic bacteria related to antibiotic resistance in the air of subway compartments and daycare centers.

A study on the ambient electromagnetic radiation level of 5G base stations in typical scenarios

Knowledge of the electromagnetic radiation characteristics of 5G base stations under different circumstances is useful for risk prevention, assessment, and management. This paper selects several typical scenes (Open spaces, building concentration areas, user and building intensive areas) for electromagnetic radiation monitoring, and analyzes the relationship between ambient radiated power density and base station background. The results show that the factors that have significant impacts on the environmental radiation power density of 5G base stations including transmission distance, base station distribution, user density, building reflection superposition and so on. The radiation energy decays rapidly with distance. When the density of the building distribution is too large, the superposition effect caused by the reflected wave is concentrated at the distance of 50-70 meters. When the user density decreases (the superposition effect of reflected waves decreases), the 5G monitoring value follows the direct wave attenuation law and decreases rapidly with the increase of distance. Points with higher measured radiation in the simple access condition also had higher measured radiation in the high-speed download condition. With the popularization of 5G mobile phones and the increase of user density, the resource utilization of a single user will decline to the normal operation state, and the radiation environmental impact will be further reduced.