Mobile Cellular Networks Research Articles

Power Consumption and GoS Tradeoff in Cellular Mobile Networks With Base Station Sleeping and Related Performance Studies

Mobile network operators usually consider power consumption and Grade of Service (GoS) as two important aspects in the design and planning of modern cellular networks. Base station (BS) sleeping is an effective approach to reduce the power consumption of the network, by switching some of the BSs to a low-power “sleep mode” during off-peak traffic hours. In this paper, we model each BS with sleeping mechanism as an M/G/1/K queue with vacations, and the entire cellular network as a network of such queues, to incorporate practical factors in BS sleeping, such as close-down and startup periods and additional power consumption for activating a sleeping BS. We investigate the power consumption and GoS under three BS sleeping schemes: (1) the isolated scheme, in which each BS switches between active and sleep modes based on its own realtime traffic load, (2) the cooperative scheme, in which selective BSs are switched to long-term sleep and traffic is allowed to overflow from sleeping BSs to nearby active BSs, and (3) the hybrid scheme, in which some BSs are switched to long-term sleep and other BSs switch modes according to their real-time traffic load. A robust, scalable and computationally efficient analytical method is proposed to evaluate GoS metrics, including mean delay and blocking probability, and power consumption under each scheme. We validate the accuracy of the proposed method, demonstrate the trade-off among power consumption, blocking probability and mean delay, and compare the performance of the three schemes via extensive and statistically reliable numerical experiments.

A Review of Cellular Networks: Applications, Benefits and Limitations

Over decades the world has witnessed stepwise evolution in Cellular networks technology and mobile network industry which have transformed nation’s economy and created job opportunities since 1970. The stepwise evolution of the cellular networks from first generation (1G) to fifth generation (5G) have shown tremendous increase in technology, benefits, user demand and applications. As new generation of cellular network unfold, the challenges and limitations of preceded generations are being tackled as always depicted in the design architecture of each new generation. The first generation (1G) cellular network was based on analogue and was able to cater for mobile voice transmission but posed some challenges in terms of quality of service and security of network. Second generation (2G) came with the introduction of digitally encrypted technology and greater security for sender and receiver with services such as text messages and MMS. Third generation (3G) was developed to offer high speed data and multimedia connections to subscribers. Fourth generation evolves from 3G with higher data rate, lower latency, greater spectral efficiency and simple protocol architecture with efficient multicast than its predecessors. Fifth-generation (5G) networks is being deployed to meet growing demands for data from consumer and industrial users and to enable the use of advanced technologies such as smart city applications, autonomous vehicles and navigation. The envisioned sixth generation (6G) of cellular network is expected to witness an unparalleled revolution that would significantly distinguish it from the existing generations and will drastically re-shape the wireless evolution from "connected thing to connected intelligence. This paper provides a comprehensive review of cellular networks applications and challenges from 1G to 6G. Keywords: 1G, 2G, 3G, 4G, 5G, 6G, Applications Benefits, and Limitations DOI: 10.7176/NCS/11-04 Publication date: December 31st 2020

Analysis of Dynamic Frequency Reuse Techniques in LTE – A Cellular Network

Inter-cell Interference (ICI) is a significant obstacle which is degrading the efficiency of mobile cellular networks particularly for end users. Frequency reuse is an ICI synchronization technique which helps to mitigate ICI by assigning dissimilar frequency reuse factors on the basis of its position to User equipment (UE). This paper proposes a Self-organized resource allocation (SORA) framework that chooses the reuse factors randomly. The output of this strategy is configured using MATLAB and correlated with numerous reuse factor combinations. Results from simulation show improved efficiency for Cell Edge Users (CEU).

Study Of Signal Quality Relationship On The Number Of Clusters And Propagation Parameters In Mobile Comumunication

A suitable telecommunications system to support a mobile communication system is a wireless communication system, which is a radio communication system complete with transmitting antennas and radio equipment. To be able to cover such a wide coverage, the coverage area is divided into sub-areas called cells. A collection of several cells is called a cluster, and several clusters will form a mobile cellular communication network area. The number of clusters in an area is affected by changes in parameters, especially the pathloss from the propagation environment. Planning in designing a communication network is needed to be able to see how much influence the parameter changes, especially the propagation attenuation factor and the number of clusters, is to make a computer program for cell planning. From the cell planning program, it can be obtained that the value of c/i is influenced by changes in the value of J when the value of n is 3.9. The value of c/i when the value of J is 3 is 6.5321. The value of c/i when the value of J is 4 is 8.4062. The value of c/i when the value of J is 5 is 9.8599. The value of c/i when the value of J is 6 is 11.0476. The value of c/i when the value of J is 7 is 12.0518. The value of c/i when the value of J is 8 is 12.9217. The value of c/i when the value of J is 9 is 13.6889. The value of c/i is influenced by changes in the value of n when the value of J is 15. The value of c/i when the value of n is 3 is 17.0167. The value of c/i when the value of n is 3.2 is 18.6698. The value of c/i when the value of n is 3.4 is 20.3231. The value of c/i when the value of n is 3.6 is 21.9761. The value of c/i when the value of n is 3.8 is 23.6293. The value of c/i when the value of n is 3.9 is 24.4561. The greater the number of cells, the greater the value of the signal ratio ratio (c/i) in the propagation. The propagation attenuation value is directly proportional to the signal ratio ratio (c/i). The greater the number of cells and the propagation attenuation, the greater the signal ratio ratio (c/i). The greater the value of the signal ratio ratio (c/i), the better the received signal quality.

Multi-dimensional Prediction Model for Cell Traffic in City Scale

Traffic prediction is a classical time series prediction which has been investigated in different domains, but most existing models are proposed based on limited time or spatial scale. Mobile cellular network traffic prediction is of paramount importance for quality-of-service (QoS) and power management of the cellular base stations, especially in the 5G era. Through the statistical analysis of the real historical traffic data obtained in a city scale spanning across multiple months, this paper makes an in-depth study of the temporal characteristics and behavior rules of the model data traffic. Considering that the time series data show different changing rules under the different time dimensions, spatial dimensions and independent dimensions, a multi-dimensional recurrent neural network (MDRNN) prediction model is established to predict the future cell traffic volume over various temporal and spatial dimensions. The data of this paper are trained and tested over real data of a city, and the granularity of the proposed prediction model can be drilled down to the cell level. Compared with the traditional trend fitting method, the proposed model achieves mean absolute percentage error (MAPE) reduction of 6.56%, and provides guidance for energy efficiency optimization and power consumption reduction of base stations in various temporal and spatial dimensions.

Unveiling large-scale commuting patterns based on mobile phone cellular network data

In this study, with Estonia as an example,we established an approach based on Hidden Markov Model to extract large-scale commuting patterns at different geographical levels using a massive amount of mobile phone cellular network data, which is referred to as Call detail record (CDR). The proposed model is designed for reconstructing and transforming the trajectories extracted from the CDR data. This step allowed us to perform origin-destination matrix extraction among different geographical levels, which helped in depicting the commuting patterns. Besides, we introduced different techniques for analyzing the commuting at the urban level. Our results unveiled that there is great potential behind mobile data of the cellular networks after transforming it into meaningful mobility patterns. That can easily be used for understanding urban dynamics, large-scale daily commuting and mobility. The aggressive development and growth of ubiquitous mobile sensing have generated valuable data that can be used with our approach for providing answers and solutions to the growing problems of transportation, urbanization and sustainability.

Monitoring System of Transmission Line in Mountainous Area Based on LPWAN

In light of the difficulty of the inspection and maintenance of a transmission line condition monitoring system in remote mountainous areas, this paper proposes a long-term online monitoring scheme based on a low power wide area network (LPWAN). Considering different failure rates, three monitoring periods of transmission lines in mountainous areas are proposed. An online monitoring framework of transmission lines in mountainous areas was designed based on long range radio (LoRa) and a cellular mobile network, and a dynamic group network model of LoRa was established. The multi-objective particle swarm optimization algorithm can be used to optimize the energy and delay of the system, and then the suitable working mode for the three monitoring periods can be obtained. The simulation results showed that the minimum packet loss rate of the system could be less than 1%, the energy consumption of the system was 80% lower than the existing monitoring system, and the service life of the system can reach 15.13 years under the normal failure rate. Compared with the existing schemes, the proposed work shows the advantages of high reliability transmission, low cost and long-term monitoring, which is especially for transmission line monitoring in mountainous areas.

Interference Minimization Resource Allocation for V2X Communication Underlaying 5G Cellular Networks

In this paper, the resource allocation for vehicle-to-everything (V2X) underlaying 5G cellular mobile communication networks is considered. The optimization problem is modeled as a mixed binary integer nonlinear programming (MBINP), which minimizes the interference to 5G cellular users (CUs) subject to the quality of service (QoS), the total available power, the interference threshold, and the minimal transmission rate. To achieve that, the original MBINP is decomposed into three steps: transmission power initialization, subchannel assignment, and power allocation. Firstly, the minimum transmission power required by the V2X users (VUs) is set as the initial power value. Secondly, the Hungarian algorithm is used to obtain the appropriate subchannel. Finally, an optimization mechanism is proposed to the power allocation. Simulation results show that the proposed algorithm can not only ensure the minimal transmission rate of VUs but also further improve the CUs’ channel capacity under the premise of guaranteeing the QoS of the CUs.

Minimizing the Signaling Overhead and Latency Based on Users’ Mobility Patterns

We demonstrate a distributed and a centralized 4G/5G compliant approach to minimize signaling and latency related to user mobility in cellular networks. This is crucial due to the densification of networks and the additional signaling introduced by the new 5G service-based architecture. By exploiting standardized protocols, our solutions dynamically reorganize the association between nodes in radio access network (RAN) and the core. We validated the proposed approaches using real user mobility datasets. Our results show that both our distributed and centralized solutions significantly reduce the signaling between core and RAN compared to the traditional approach based on geographical proximity. As a result, both approaches significantly reduce the average handover procedure processing time. Moreover, by relying on locally available information, the distributed approach can quickly adapt to changes in the user movement patterns as they happen.

Performance Analysis of Millimeter-Wave UAV Swarm Networks under Blockage Effects.

Due to their high mobility, unmanned aerial vehicles (UAVs) can offer better connectivity by complement or replace with the existing terrestrial base stations (BSs) in the mobile cellular networks. In particular, introducing UAV and millimeter wave (mmWave) technologies can better support the future wireless networks with requirements of high data rate, low latency, and seamless connectivity. However, it is widely known that mmWave signals are susceptible to blockages because of their poor diffraction. In this context, we consider macro-diversity achieved by the multiple UAV BSs, which are randomly distributed in a spherical swarm. Using the widely used channel model incorporated with the distance-based random blockage effects, which is proposed based on stochastic geometry and random shape theory, we investigate the outage performance of the mmWave UAV swarm network. Further, based on our analysis, we show how to minimize the outage rate by adjusting various system parameters such as the size of the UAV swarm relative to the distance to the receiver.

A Study on Packet Scheduling Algorithms for Healthcare Contents over Fifth Generation (5G) Mobile Cellular Network

A Study on Packet Scheduling Algorithms for Healthcare Contents over Fifth Generation (5G) Mobile Cellular Network

Design of a New Type of Optical Fiber Infrasound Sensor and Its Usage in Karst Geological Exploration

In this study, the demand of optical fiber (OF) sonic sensor is analyzed, and a composite OF infrasound sensor is proposed aiming at the detection demand of low-frequency infrasound waves in specific occasions. With this sensor, the polymer thin film and the aluminum soil can be combined to form a kind of composite film, the ECF/P interferometer can be formed between the end faces of the ferrule of the OF FC contact, the sensor head of the OF ECF/P infrasound sensor system is fabricated and then packaged. The designed OF infrasound sensor is used in the construction of a wireless sensor network (WSN) for karst geological exploration. The structure of the WSN includes the SimpliciTI communication network protocol, ADF7021 RF transceiver chip, STM32 processor chip, etc. New types of environment from karst can be sampled with this WSN. During the test, the performance of the composite OF infrasound sensor is analyzed at the beginning. The acoustic sensitivity of up to –136.73 dB re 1 V/μPa can be obtained in the low frequency infrasound range (1–20 Hz); the WSN based on the composite OF infrasound sensor has lower power consumption and faster networking speed. In addition, it can realize signal cover in karst areas without public mobile cellular networks, and send the information collected by the sensor to the data center, thus proving the fiber optic sound wave sensor designed in this study is successful and helpful for the geological prospectors to monitor the environment.

Modeling of OpenFlow-related handover messages in mobile networks

Software defined networking (SDN) and its most popular southbound implementation OpenFlow (OF) are already greatly exploited in the existing mobile cellular networks as part of data centers and mobile core networks. Due to user’s mobility, it is of upmost importance for the operators to provide the shortest possible interruption when the mobile users are performing the procedure of handover. In this work, we proposed a novel analytical approach to model the OF-related handover messages exchanged between the OF-switches and the SDN controller. We modeled two different OF-switch implementations and we compared the results: (1) single shared buffer used for the control and data plane; (2) two priority buffers, where the data plane packets are served only when there are no packets to be processed in the control plane. We numerically evaluated the two systems and we validated the model by using simulations. The obtained results clearly point that although the priority buffering increased the complexity, it effectively provided the shortest handover delay. Therefore, the priority buffering should be the preferred mechanism for mobile networks.

Performance analysis of image transmission with various channel conditions/modulation techniques

This paper investigates the impact of different modulation techniques for digital communication systems that employ quadrature phase shift keying (QPSK) and quadrature amplitude modulation (16-QAM and 64-QAM) to transmit images over AWGN and Rayleigh fading channels for the cellular mobile networks. In the further steps, wiener and median filters has been adopted to the simulation are used at the receiver side to remove the impulsive noise present in the received image. This work is performed to evaluate the transmission of two dimensional (2D) gray-scale and color-scale (RGB) images with different values from signal to noise ratios (SNR), such as; (5, 10 and 15) dB over different channels. The correct conclusions are made by comparing many of the observed Matlab simulation results. This was carried out through the results that measure the quality of received image, which is analyzes in terms of SNRimage peak signal to noise ratio (PSNR) and mean square error (MSE).

Optimized channel allocation in emerging mobile cellular networks

The task of optimizing service quality in wireless networks is a continuous research that requires the design of efficient channel allocation schemes. The problem is how limited channel resources can be maximally utilized, to guarantee seamless communication while maintaining excellent service quality. Whereas, fixed channel allocation (FCA) schemes treat new and handoff calls equally without preference to normally prioritized handoff calls; dynamic channel allocation (DCA) schemes accommodate users mobility in randomly changing network conditions. However, classical Erlang-B models are deficient and do not consider users mobility and dynamically changing traffic of the mobile network environment. A modified Erlang-B dynamic channel allocation (MEB-DCA) scheme is therefore introduced in this paper, for improved network performance. The MEB-DCA algorithm introduces a conditional threshold for handoff request assignment to ensure that communication systems do not unnecessarily prioritize handoff calls at the detriment of new calls. Deriving knowledge from imprecise network data is difficult when developing functional relationships between parameters, requiring advanced modeling techniques with cognitive experience. Soft computing techniques have been shown to handle this challenge given its ability to represent precisely, both data and expert knowledge. An adaptive neuro-fuzzy inference system-based dynamic channel allocation (ANFIS-DCA) framework was proposed to automate the learning of communication parameters for optimized channel allocation decisions. Network parameters considered were received signal strength indication impacted by user mobility, number of guard and general channels, carried traffic, and handoff blocking threshold. The performance of the proposed ANFIS-DCA model was found to outsmart the static FCA and back propagation neural network-based DCA (NN-DCA) schemes using mean square error and root mean square error as performance measures. Our approach can be effectively deployed to improve channel allocation, resource utilization, network capacity, and satisfy users experience.

Improvement and Testing of Models for Field Level Evaluation in Urban Environment

Through the advent of mobile cellular networks the number of radio base stations installed in urban environments has increased exponentially. As a consequence, the level of the electromagnetic (EM) field has increased at the same pace, sometimes approaching the limits set by the national rules. The first step of a compliance test campaign is the field estimation, mainly close to the base stations. In this article, the estimation of EM field generated by UHF base station is presented. A rephrasing of the COST 231 - Walfisch-Ikegami model is used to evaluate the path loss at distances greater than 20 m from the base station. Then, the knowledge of the full antenna pattern allows to estimate the field level. Since antenna manufacturers measure, and publish, only the patterns on the principal planes, an extrapolation procedure is also presented. A measurement campaign in the specific small urban and irregular environments of Dorgali (NU), Cala Gonone (NU) and Lunamatrona (CA), Italy, done in the context of Onde Chiare project, has been used to assess the approach presented here.

A Survey on WSN and MCN Convergence Networks

In this paper, we present a survey concerned with research focusing on the convergence of wireless sensor networks (WSN) and mobile cellular networks (MCN). The convergence of WSNs and MCNs may be a trigger stimulating new research dealing with such issues as architecture, protocols and air interfaces. The highlights and constraints of the phenomenon are discussed in this paper as well. The survey deals with convergence networks and with their smarty city applications. A few open research issues are also brought to the attention of researchers specializing in this field

5G and Wi-Fi 6 Milestones

Papers in the March 2020 issue of the Journal include discussion on the future of the $51 billion National Broadband Network (NBN), IoT device and system management and the mobile cellular networks in Indonesia. The Telecommunications Association is hosting public forums on the future of the NBN in 2020 at RMIT University in Melbourne. The Australian mobile network operators continue to rollout 5G and Telstra has announced a 5G milestone. In the U.S., the FCC has announced the allocation of 1,200 MHz in the 6 GHz band for unlicensed use including Wi-Fi 6. The Journal welcomes contributions on telecommunications and the digital economy.

A New Green Prospective of Non-orthogonal Multiple Access (NOMA) for 5G

Energy efficiency is a major concern in the emerging mobile cellular wireless networks since massive connectivity is to be expected with high energy requirements from the network operators. Non-orthogonal multiple access (NOMA) being the frontier multiple access scheme for 5G, there exists numerous research attempts on enhancing the energy efficiency of NOMA enabled wireless networks while maintaining its outstanding performance metrics such as high throughput, data rates and capacity maximized optimally.The concept of green NOMA is introduced in a generalized manner to identify the energy efficient NOMA schemes. These schemes will result in an optimal scenario in which the energy generated for communication is managed sustainably. Hence, the effect on the environment, economy, living beings, etc is minimized. The recent research developments are classified for a better understanding of areas which are lacking attention and needs further improvement. Also, the performance comparison of energy efficient, NOMA schemes against conventional NOMA is presented. Finally, challenges and emerging research trends, for energy efficient NOMA are discussed.

Optimal management of distance-based location registration using embedded Markov chain

In this study, we deal with a Distance-Based Registration with Implicit Registration, which is an enhanced scheme of the Distance-Based Registration in mobile-cellular networks. In comparisons with other Location Registration schemes, various studies on the Distance-Based Registration scheme and performance have been performed. However, a real network hierarchy has not been properly reflected in the performance evaluation of the Distance-Based Registration. To accurately evaluate the registration and paging costs of the Distance-Based Registration, a real network hierarchy should reflect that a mobile network is made up of many Visitor Location Register areas. Furthermore, we use an embedded Markov-Chain model in the Visitor Location Register hierarchy, which can reflect not only the Implicit Registration effect of the outgoing calls of user equipment but also cell staying time of the user equipment that may follow a general distribution. Without consideration of the Visitor Location Register, the paging cost decreases due to a small paging area, but the location registration cost rises because of frequent inter Visitor Location Register. The numerical results according to the various conditions show an accurate evaluation of the Distance-Based Registration performance in a real network hierarchy and the general cell staying time. Generally, the total signaling cost will increase when we consider the Visitor Location Register. However, for more appropriate evaluation of the Distance-Based Registration performance, it is necessary to consider the Visitor Location Register hierarchy.