Customer Churn Prediction in Telecom Sector: A Survey and way a head

© 2021 International Journal of Scientific & Technology Research. This work is licensed under a Creative Commons Attribution 4.0 International License.The telecommunication (telecom)industry is a highly technological domain has rapidly developed over the previous decades as a result of the commercial success in mobile communication and the internet. Due to the strong competition in the telecom industry market, companies use a business strategy to better understand their customers’ needs and measure their satisfaction. This helps telecom companies to improve their retention power and reduces the probability to churn. Knowing the reasons behind customer churn and the use of Machine Learning (ML) approaches for analyzing customers' information can be of great value for churn management. This paper aims to study the importance of Customer Churn Prediction (CCP) and recent research in the field of CCP. Challenges and open issues that need further research and development to CCP in the telecom sector are exploredPeer reviewe

Design of Radiation Pattern-Reconfigurable 60-GHz Antenna for 5G Applications

noReconfigurable beam steering using circular disc microstrip patch antenna with a ring slotis proposed. The overall dimension of the antenna is 5.4×5.4 mm2 printed on a 0.504 mm thick, Rogers RT5870 substrate with relative permittivity 2.3 and loss tangent 0.0012. The designed antenna operates at the expected 5G frequency band 60 GHz with a central coaxial probe feed. TwoNMOS switches are configured to generate three different beam patterns. Activating each switch individually results in a near 70 degree shift in the main beam direction, whereas the frequency characteristics are unchanged. The power gains are between 3.9 dB and 4.8dB for the three states of switches configurations. Simulated results in terms of return loss, peak gains and radiation pattern are presented and show a reasonable agreement at the expected 60 GHz bandfor 5G applications.The published journal webpage is no longer available

Performance Comparison of Particle Swarm Optimization, and Genetic Algorithm in the Design of UWB Antenna

yesAn efficient multi-object evolutionary algorithms are proposed for optimizing frequency characteristics of antennas based on an interfacing created by Matlab environment. This interface makes a link with CST Microwave studio where the electromagnetic investigation of antenna is realized. Very small, compact printed monopole antenna is optimized for ultra- wideband (UWB) applications. Two objective functions are introduced; the first function intends to increase the impedance bandwidth, and second function to tune the antenna to resonate at a particular frequency. The two functions operate in the range of 3.2 to 10.6 GHz and depend on the level of return loss. The computed results provide a set of proper design for UWB system in which the bandwidth achieved is 7.5GHz at the resonance frequency 4.48GHz, including relatively stable gain and radiation patterns across the operating band

Fabrication of Te Micro-Tubes and TeO2 Micro-Wires From Powders by Cold Spray

A one-dimensional micro-structured tellurium (Te) microtube and tellurium dioxide (TeO2) microwire were successfully prepared by cold spray process in large scale by a facile approach of sprayed (Te), (TeO2) dry powder in an inert atmosphere using helium gas onto glass substrate. Tellurium and Tellurium dioxide were sprayed by heating carrier gas at (200,300,400 and 500 °C) and 2 MPa pressure on the glass substrate (100°C). Heat treatment was done under vacuum (0.0133mbar) for (30 min) at (200°C) for Te and (400°C) for TeO2.The prepared microtubes and microwire was examined by XRD, AFM and SEM. The result showed that the obtained microtubes and microwire were highly pure

Design of Frequency Reconfigurable Multiband Compact Antenna using two PIN diodes for WLAN/WiMAX Applications

YesIn this paper, we present a simple reconfigurable multiband antenna with two PIN diode switches for WiMAX/WLAN applications. The antenna permits reconfigurable switching in up to ten frequency bands between 2.2 GHz and 6 GHz, with relative impedance bandwidths of around 2.5% and 8%. The proposed antenna has been simulated using CST microwave studio software and fabricated on an FR-4 substrate. It is compact, with an area of 50 × 45 mm2, and has a slotted ground substrate. Both measured and simulated return loss characteristics of the optimized antenna show that it satisfies the requirement of 2.4/5.8 GHz WLAN and 3.5 GHz WiMAX antenna applications. Moreover, there is good agreement between the measured and simulated result in terms of radiation pattern and gain.Engineering and Physical Science Research Council through Grant EP/E022936A

Harmonic-suppression Using Adaptive Surface Meshing and Genetic Algorithms

yesA novel design strategy for microstrip harmonic-suppression antennas is presented. The computational method is based on an integral equation solver using adaptive surface meshing driven by a genetic algorithm. Two examples are illustrated, all involving design of coaxially-fed air-dielectric patch antennas implanted with shorting and folded walls. The characteristics of the antennas in terms of the impedance responses and far ¯eld radiation patterns are discussed theoretically and experimentally. The performances of all of the GA-optimised antennas were shown to be excellent and the presented examples show the capability of the proposed method in antenna design using GA.MSCR

Study on the effect of the substrate material type and thickness on the performance of the filtering antenna design

This article presents a new design of a four-pole microstrip filtering antenna. The filtering antenna consists of a bandpass filter, which has four resonators integrated to a monopole patch antenna. The filtering antenna is designed with a relatively high bandwidth of about 1.22 GHz to satisfy a high-speed data transmission. Three types of dielectric substrate materials were used for the design of the filtering antenna, which is RT/Duroid 5880, RO3003, and FR-4. The simulation results of the filtering antenna design, which are established on the three different dielectric substrate materials, are done by using Computer Simulation Technology (CST) software. Comparison results of the filtering antenna that is established on the three different dielectric substrate materials are done at a fixed substrate height and different substrate heights. The filtering antenna is designed at a center frequency f0 = 2.412 GHz, which is suitable for WLAN applications

Design of 2x2 U-shape MIMO slot antennas with EBG material for mobile handset applications.

yesA compact dual U-shaped slot PIFA antenna with Electromagnetic Bandgap (EBG) material on a relatively low dielectric constant substrate is presented. Periodic structures have found to reduce mutual coupling and decrease the separation of antenna and ground plane. A design with EGB material suitable for a small terminal mobile handset operating at 2.4 GHz was studied. Simulated and measured scattering parameters are compared for U-shaped slot PIFA antenna with and without EBG structures. An evaluation of MIMO antennas is presented, with analysis of the mutual coupling, correlation coefficient, total active reflection coefficient (TARC), channel capacity and capacity loss. The proposed antenna meets the requirements for practical application within a mobile handset.Electronics and Telecommunication

A Frequency Tunable PIFA Design for Handset Applications.

yesA frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is tunable over from 1850 MHz to 2200 MHz, with an associated volume of 21×13.5×5 mm3, making it suitable for potential integration in a commercial handset or mobile user terminal